Tiger I, Pershing & a T34
07-09-2018, 02:48 AM
#1
Thread Starter
Join Date: Jul 2018
Posts: 44
Likes: 0
Received 0 Likes
on
0 Posts
Tiger I, Pershing & a T34
Hi to all I'm a new signatory here but have been a modeller and RC hobbyist for 42 years.
I go back to a Tamiya CS Countach and aero engines with a compression screw.
I could probably count my RC vehicles but would prefer not to, I do know it's over 300 and I have over 100 working internal combustion engines.
If it spins I'm there.
I ran a hobby shop for several years and have several degrees, engineering, electronics etc so I'm not a Noob in the classic sense.
Bought my first tank in 2005 and have played on and off since then.
I've just finished a 1:7 scale Spitfire and a 1:5 scale Sopwith Camel
The last few years have been 1:5 scale buggies with 30cc Gas engines and some electric crawlers.
I've also got one of every series of RC10 ever made in better than V-good condition.
Slot cars, an 80 ft AFX layout and some 1/24 competition stuff.
Now I'm going to have a go at doing tanks to a respectable level.
This forum seems to be one of the better "Tankcentric" so I think that I'll concentrate my efforts here for the moment.
I've read every post from the last 2 years and so I'm pretty switched on in the level of knowledge and have taken much with me into my realignment towards 1:16 scale and tracks. I've also done the odd robot and Pi/arduino so that stuff is OK as well as a few drones and have a few 250 FPV racers as well as a couple of 450 size that I've been using for AI programming so I hope I can bring some of that tech to my Tanking.
I recently acquired a Bulldog , a Panther and a King Tiger as well and am looking for a Leopard at the right price.
I intend to do a series of build logs that would reflect the levels I'd recommend as the old school LHS bloke would do. Not extreme modding or severely over complicated controllers but good value solutions that you can grow with.
I am sure that the hard core tankers will chip in with invaluable advice but what I'd like to do is to show how you can get a good quality Tank going with relatively inexpensive kit.
I won't do scale, this is for those dedicated to it and from what I've seen here some of you do insanely good work, I'm going to work with a definitive set of hardware and electronic sets and optimise the user satisfaction.
And thus this adventure begins...
...with an old school Heng Long Pershing.
I'll update the electronics to an RX-18
Driven by a 9XR radio
and cleaned up internals.
For less than $100
We'll Get a a hobby grade i6x radio and mod it for centering on the throttle and assign other uses to some other channels.
For less than $90
Better motors and some reasons why.
A lot of stuff has been addressed so if I'm going somewhere and it's a redundant post interrupt and point me to the post.
Making it easy for a new tanker is the priority.
Then we'll do an OPENPANZER config.
I see this as the future of RC Tanks.
I'd just like to share some of the stuff I've learned and show it to a new community.
To a long and fruitful future
Salut'
Bill
I go back to a Tamiya CS Countach and aero engines with a compression screw.
I could probably count my RC vehicles but would prefer not to, I do know it's over 300 and I have over 100 working internal combustion engines.
If it spins I'm there.
I ran a hobby shop for several years and have several degrees, engineering, electronics etc so I'm not a Noob in the classic sense.
Bought my first tank in 2005 and have played on and off since then.
I've just finished a 1:7 scale Spitfire and a 1:5 scale Sopwith Camel
The last few years have been 1:5 scale buggies with 30cc Gas engines and some electric crawlers.
I've also got one of every series of RC10 ever made in better than V-good condition.
Slot cars, an 80 ft AFX layout and some 1/24 competition stuff.
Now I'm going to have a go at doing tanks to a respectable level.
This forum seems to be one of the better "Tankcentric" so I think that I'll concentrate my efforts here for the moment.
I've read every post from the last 2 years and so I'm pretty switched on in the level of knowledge and have taken much with me into my realignment towards 1:16 scale and tracks. I've also done the odd robot and Pi/arduino so that stuff is OK as well as a few drones and have a few 250 FPV racers as well as a couple of 450 size that I've been using for AI programming so I hope I can bring some of that tech to my Tanking.
I recently acquired a Bulldog , a Panther and a King Tiger as well and am looking for a Leopard at the right price.
I intend to do a series of build logs that would reflect the levels I'd recommend as the old school LHS bloke would do. Not extreme modding or severely over complicated controllers but good value solutions that you can grow with.
I am sure that the hard core tankers will chip in with invaluable advice but what I'd like to do is to show how you can get a good quality Tank going with relatively inexpensive kit.
I won't do scale, this is for those dedicated to it and from what I've seen here some of you do insanely good work, I'm going to work with a definitive set of hardware and electronic sets and optimise the user satisfaction.
And thus this adventure begins...
...with an old school Heng Long Pershing.
I'll update the electronics to an RX-18
Driven by a 9XR radio
and cleaned up internals.
For less than $100
We'll Get a a hobby grade i6x radio and mod it for centering on the throttle and assign other uses to some other channels.
For less than $90
Better motors and some reasons why.
A lot of stuff has been addressed so if I'm going somewhere and it's a redundant post interrupt and point me to the post.
Making it easy for a new tanker is the priority.
Then we'll do an OPENPANZER config.
I see this as the future of RC Tanks.
I'd just like to share some of the stuff I've learned and show it to a new community.
To a long and fruitful future
Salut'
Bill
Last edited by Brycevr; 07-09-2018 at 02:56 AM.
07-09-2018, 03:40 AM
#2
Thread Starter
Join Date: Jul 2018
Posts: 44
Likes: 0
Received 0 Likes
on
0 Posts
Here's where I'll start, with a Pershing that's been on my shelf and screwed with for about 14 years.
It came with the old open PCB TX-13 board and was at best a nightmare and at worst a start for a scale shelf queen.
All work on all tanks will begin with separating the upper and lower hulls.
Remove all extraneous features from the upper hull as they are more easily refitted after being removed properly than trying to put them back after they've been broken off. This will also clear the way for detailing and attaching optional peripherals.
You will find that most are attached by posts glued into holes in the hull. You will break some of these and we'll show a new way that you can re-attach them if this does happen in the top hull tutorial later.
In anticipation of this event, acquire some pin vises and some small drills. 1.5mm to 3mm in as many graduations as you can afford.
A Dremel and the basic bits is also a REALLY handy thing to have.
The number of screws and their location will vary but in some cases this can be a little bit complicated.
On some models you will have to remove the tracks.
Generally after doing this for the first time you'll identify the key points and use these only. Some experienced modellers use magnetic catches or spring catches to re-attach the upper hull.
You can explore this but for the moment find 6-8 key screws and use these. You will be splitting the hulls VERY often as you learn and test all of your new found magic.
PRO TIP #1 Never use an electric driver, the speed and friction will soften the plastic and you will strip screws easily, to re insert properly, insert the screw and back around until you feel a "tick" this is the beginning of the original thread and then load down and you'll find the screws will thread in evenly and clean.
PRO TIP #2 drop a bit of CA (a minute amount) down the female screw posts to reinforce them. Don't fill the hole but just a touch to harden the plastic. I use a toothpick
Lift the upper shell away and you will find a white 8 pin JST XH connector that connects the upper hull functions to the controller unit.
Gently but firmly detach this connector.
The upper and lower hulls should be separated now.
and thus we end lesson #1
(pics tomorrow)
B
It came with the old open PCB TX-13 board and was at best a nightmare and at worst a start for a scale shelf queen.
All work on all tanks will begin with separating the upper and lower hulls.
Remove all extraneous features from the upper hull as they are more easily refitted after being removed properly than trying to put them back after they've been broken off. This will also clear the way for detailing and attaching optional peripherals.
You will find that most are attached by posts glued into holes in the hull. You will break some of these and we'll show a new way that you can re-attach them if this does happen in the top hull tutorial later.
In anticipation of this event, acquire some pin vises and some small drills. 1.5mm to 3mm in as many graduations as you can afford.
A Dremel and the basic bits is also a REALLY handy thing to have.
The number of screws and their location will vary but in some cases this can be a little bit complicated.
On some models you will have to remove the tracks.
Generally after doing this for the first time you'll identify the key points and use these only. Some experienced modellers use magnetic catches or spring catches to re-attach the upper hull.
You can explore this but for the moment find 6-8 key screws and use these. You will be splitting the hulls VERY often as you learn and test all of your new found magic.
PRO TIP #1 Never use an electric driver, the speed and friction will soften the plastic and you will strip screws easily, to re insert properly, insert the screw and back around until you feel a "tick" this is the beginning of the original thread and then load down and you'll find the screws will thread in evenly and clean.
PRO TIP #2 drop a bit of CA (a minute amount) down the female screw posts to reinforce them. Don't fill the hole but just a touch to harden the plastic. I use a toothpick
Lift the upper shell away and you will find a white 8 pin JST XH connector that connects the upper hull functions to the controller unit.
Gently but firmly detach this connector.
The upper and lower hulls should be separated now.
and thus we end lesson #1
(pics tomorrow)
B
Last edited by Brycevr; 07-09-2018 at 03:58 AM.
07-09-2018, 04:06 AM
#4
Thread Starter
Join Date: Jul 2018
Posts: 44
Likes: 0
Received 0 Likes
on
0 Posts
I'm going for a sort of "big dummies" guide thing. Get more people comfortable and everyone wins.
Not everyone is a battler or a scale giant, sometimes just driving the tank around the yard and shooting the dog is enough fun.
Not everyone is a battler or a scale giant, sometimes just driving the tank around the yard and shooting the dog is enough fun.
07-09-2018, 12:48 PM
#7
I look forward to seeing your ideas and approach to R/C tanks.
07-11-2018, 12:49 AM
#8
Thread Starter
Join Date: Jul 2018
Posts: 44
Likes: 0
Received 0 Likes
on
0 Posts
I am working on the battery, motors and radio segment now as there is a lot of tankcenrtric info but not a lot of the generic info explained fully.
Next post tonight I hope.
Ordered my Open Panzer board but really should buy an ASP and ElMod as well to do a fair comparison.
Next post tonight I hope.
Ordered my Open Panzer board but really should buy an ASP and ElMod as well to do a fair comparison.
07-11-2018, 02:01 AM
#9
Thread Starter
Join Date: Jul 2018
Posts: 44
Likes: 0
Received 0 Likes
on
0 Posts
Batteries
Batteries seem to be an area where there is conflicting and often misinterpreted information.
To put it simply, the Volts is the power of the battery (how fast it will turn a motor, how brightly it will light a lamp etc).
Amps is how long it will do it for. Unless you're using a lot of amps a big battery (in Mah)is no faster.
It generally corresponds to how long the device will run.
From my limited experience a 2Ah battery will give my about 30-40 minutes of normal "playtime" on my tanks.
A normal "stick pack" that comes with your tank is about 1800-3000 Mah and is usually an arrangement of 6 x 1.2v per cell NiCd or NiMh. Nominally 7.2V for the pack.
Whilst they work fine a LiPo Lithium Polymer pack is much more efficient and compact as well as offering slightly more voltage (3.7v per cell) 2 x 3.7=7.4v.
Using batteries any of higher voltage in a 1/16 tank is a recipe for disaster. The circuits and drivetrain are designed around the 7-8v paradigm and so all of the electronics, and mechanical components are optimised in these ranges. I've done a 12v system for giggles and used a tank mixer with car ESC's. Stripped gear boxes and a thrown track was my reward. It was fast for a while though.
I'd imagine 12v and 30-40A esc's for a 1/8 or 1/6th scale.
Our basic 1/16 tank in standard form draws about 1.2amps per side flat-out along the ground with 500gms of ballast. Up hill and in stall conditions this would go up considerably but they really don't use much, my simple run time observation from above seems to concur.
So, our actual POWER is... 7.5v x 1.2A = 9 watts per track x2 =18 watts total. The ancillaries use so little as to be inconsequential.
There is no definitive as everyone drives differently and batteries are not all equal.
Do not bother even keeping NiCads. The technology is so old and their care is so fussy it's just not worth it.
Remember the "memory effect" this is exclusive to NiCads and their energy density is pitiful. I began RC racing in 1983 and that was all we had so I know all of the pitfalls of a a NiCad and there are many.
NiMh cells have had their day in the sun, I still use them and they are a good idea for the standard tank config.
Slow charge rates and bulk are the biggest disadvantage but for all intents and purposes they work well. (remember they are still 1.2v per cell x 6 = 7.2v) They usually only come in the standard "SubC" rendered a standard by the RC car racing community back in the '80's
I'll drop in a truism here that my father imparted many years ago...
"A new item does not render the old one incapable of still doing its job"
So there is nothing wrong with using those old batteries lying around.
Lipo's are here to stay so this next segment is probably of the most interest.
Personally I see the biggest advantage is the ability to use different configuration and sizes to allow for chassis layout optimisation.
A 2.5Ah LiPo with a hard case is smaller than a packet of cigarettes, (not a politically correct simile but I'm sticking with it).
Personally I have been using 18650 cells, they look like a AA on steroids and are the most common LiPo cells in the world.
Most laptop packs are 18650 cells in a series/parallel arrangement, likewise most power tool packs. This is why we see common voltage ranges in most tool marketing (a lot of manufacturers round up to 4.0v per cell as a fully charged LiPo is about 4.15-4.2v).
Elon musk uses these by the 1000's in modular arrangement to drive his legendary TESLA's.
So there we have a cheap source for LiPos without breaking the bank. Most laptop and tool packs fail because 1 cell dies, some manufacturers put a cell count and the battery dies whilst still being perfectly good.
We are not going for hyper performance here, our use is mild and if you can obtain the cells from recycling then you have an ample supply of cheap cells.
Lipos also feature another specification that seems to confuse people
The infamous "C" rating.
Simply put a batteries capacity means the it will deliver its rated voltage at that current for an hour.
The "C" rating is a multiplier of its current that it can deliver continually.
So...
A 7.4v 2500mAh 10c battery will deliver 10 times the rated current in our example 25amps continuous for 6 minutes.
Using the same formula 7.4v 2500mAh 40c battery will give us 100amps for 90 seconds. This is important for racing cars and planes as often a large current surge is needed on acceleration of in the case of planes stunt manoeuvres.
Now you might understand why we often see 80-100 amp ESC in cars and for a 1.2m metre scale warbird a 60-80A ESC is common. They need to deliver very strong bursts of power but again how you drive/fly can drastically effect the runtime of any of these devices.
The effect of not having sufficient capacity or "C rating" feels like the battery is flat. It cannot deliver the required power.
Our tanks have relatively no dynamics in the drivetrain and so a 2000mAh battery of about 8C is all that is really needed.
Having a better rated battery will not hurt but any hi performance LiPo is completely redundant in this application, a battery of 5C is sufficient run a standard chassis.
I'll follow up with some example photos soon (Later tonight if I can).
I just bought some new Battery cradles and will do a tutorial on fitting a 2 cell 18650 holder into a standard chassis, a cheap and effective very simple and cheap upgrade for a standard unit.
To put it simply, the Volts is the power of the battery (how fast it will turn a motor, how brightly it will light a lamp etc).
Amps is how long it will do it for. Unless you're using a lot of amps a big battery (in Mah)is no faster.
It generally corresponds to how long the device will run.
From my limited experience a 2Ah battery will give my about 30-40 minutes of normal "playtime" on my tanks.
A normal "stick pack" that comes with your tank is about 1800-3000 Mah and is usually an arrangement of 6 x 1.2v per cell NiCd or NiMh. Nominally 7.2V for the pack.
Whilst they work fine a LiPo Lithium Polymer pack is much more efficient and compact as well as offering slightly more voltage (3.7v per cell) 2 x 3.7=7.4v.
Using batteries any of higher voltage in a 1/16 tank is a recipe for disaster. The circuits and drivetrain are designed around the 7-8v paradigm and so all of the electronics, and mechanical components are optimised in these ranges. I've done a 12v system for giggles and used a tank mixer with car ESC's. Stripped gear boxes and a thrown track was my reward. It was fast for a while though.
I'd imagine 12v and 30-40A esc's for a 1/8 or 1/6th scale.
Our basic 1/16 tank in standard form draws about 1.2amps per side flat-out along the ground with 500gms of ballast. Up hill and in stall conditions this would go up considerably but they really don't use much, my simple run time observation from above seems to concur.
So, our actual POWER is... 7.5v x 1.2A = 9 watts per track x2 =18 watts total. The ancillaries use so little as to be inconsequential.
There is no definitive as everyone drives differently and batteries are not all equal.
Do not bother even keeping NiCads. The technology is so old and their care is so fussy it's just not worth it.
Remember the "memory effect" this is exclusive to NiCads and their energy density is pitiful. I began RC racing in 1983 and that was all we had so I know all of the pitfalls of a a NiCad and there are many.
NiMh cells have had their day in the sun, I still use them and they are a good idea for the standard tank config.
Slow charge rates and bulk are the biggest disadvantage but for all intents and purposes they work well. (remember they are still 1.2v per cell x 6 = 7.2v) They usually only come in the standard "SubC" rendered a standard by the RC car racing community back in the '80's
I'll drop in a truism here that my father imparted many years ago...
"A new item does not render the old one incapable of still doing its job"
So there is nothing wrong with using those old batteries lying around.
Lipo's are here to stay so this next segment is probably of the most interest.
Personally I see the biggest advantage is the ability to use different configuration and sizes to allow for chassis layout optimisation.
A 2.5Ah LiPo with a hard case is smaller than a packet of cigarettes, (not a politically correct simile but I'm sticking with it).
Personally I have been using 18650 cells, they look like a AA on steroids and are the most common LiPo cells in the world.
Most laptop packs are 18650 cells in a series/parallel arrangement, likewise most power tool packs. This is why we see common voltage ranges in most tool marketing (a lot of manufacturers round up to 4.0v per cell as a fully charged LiPo is about 4.15-4.2v).
Elon musk uses these by the 1000's in modular arrangement to drive his legendary TESLA's.
So there we have a cheap source for LiPos without breaking the bank. Most laptop and tool packs fail because 1 cell dies, some manufacturers put a cell count and the battery dies whilst still being perfectly good.
We are not going for hyper performance here, our use is mild and if you can obtain the cells from recycling then you have an ample supply of cheap cells.
Lipos also feature another specification that seems to confuse people
The infamous "C" rating.
Simply put a batteries capacity means the it will deliver its rated voltage at that current for an hour.
The "C" rating is a multiplier of its current that it can deliver continually.
So...
A 7.4v 2500mAh 10c battery will deliver 10 times the rated current in our example 25amps continuous for 6 minutes.
Using the same formula 7.4v 2500mAh 40c battery will give us 100amps for 90 seconds. This is important for racing cars and planes as often a large current surge is needed on acceleration of in the case of planes stunt manoeuvres.
Now you might understand why we often see 80-100 amp ESC in cars and for a 1.2m metre scale warbird a 60-80A ESC is common. They need to deliver very strong bursts of power but again how you drive/fly can drastically effect the runtime of any of these devices.
The effect of not having sufficient capacity or "C rating" feels like the battery is flat. It cannot deliver the required power.
Our tanks have relatively no dynamics in the drivetrain and so a 2000mAh battery of about 8C is all that is really needed.
Having a better rated battery will not hurt but any hi performance LiPo is completely redundant in this application, a battery of 5C is sufficient run a standard chassis.
I'll follow up with some example photos soon (Later tonight if I can).
I just bought some new Battery cradles and will do a tutorial on fitting a 2 cell 18650 holder into a standard chassis, a cheap and effective very simple and cheap upgrade for a standard unit.
Last edited by Brycevr; 07-11-2018 at 02:51 AM. Reason: inevitable typo
07-11-2018, 04:15 AM
#10
Join Date: Jul 2013
Location: Palm, PA
Posts: 70
Likes: 0
Received 0 Likes
on
0 Posts
Good write up for the batteries. Coming from RC Crawlers and on-road cars its surprising how few people seem to use Lipos in tanks considering how popular they are in other RC segments. Seems to be a lot of mis-information on them floating around. One thing that you did not mention about them though is proper use and storage which is the key for staying safe. Things such as fireproof storage/charging area, making sure not to over discharge or over charge, storage voltage, visual inspection for general condition, proper balance charger and finally disposal. Long story short if you follow best practices for Lipos they are a great battery technology to use.
07-11-2018, 05:14 AM
#11
Join Date: Feb 2015
Location: Alexandria, Minnesota, USA
Posts: 493
Received 0 Likes
on
0 Posts
Welcome to the forum Bill.
It appears you can bring some helpful knowledge to the forum.
The electronics part seems to be the biggest concern for tankers, from what I can see.
I have used a couple, and am now trying out a couple Open Panzers. Curious to see your
comments when you get yours.
Enjoy,
Shad
It appears you can bring some helpful knowledge to the forum.
The electronics part seems to be the biggest concern for tankers, from what I can see.
I have used a couple, and am now trying out a couple Open Panzers. Curious to see your
comments when you get yours.
Enjoy,
Shad
07-11-2018, 10:36 AM
#12
Batteries seem to be an area where there is conflicting and often misinterpreted information.
To put it simply, the Volts is the power of the battery (how fast it will turn a motor, how brightly it will light a lamp etc).
Amps is how long it will do it for. Unless you're using a lot of amps a big battery (in Mah)is no faster.
It generally corresponds to how long the device will run.
From my limited experience a 2Ah battery will give my about 30-40 minutes of normal "playtime" on my tanks.
A normal "stick pack" that comes with your tank is about 1800-3000 Mah and is usually an arrangement of 6 x 1.2v per cell NiCd or NiMh. Nominally 7.2V for the pack.
Whilst they work fine a LiPo Lithium Polymer pack is much more efficient and compact as well as offering slightly more voltage (3.7v per cell) 2 x 3.7=7.4v.
Using batteries any of higher voltage in a 1/16 tank is a recipe for disaster. The circuits and drivetrain are designed around the 7-8v paradigm and so all of the electronics, and mechanical components are optimised in these ranges. I've done a 12v system for giggles and used a tank mixer with car ESC's. Stripped gear boxes and a thrown track was my reward. It was fast for a while though.
I'd imagine 12v and 30-40A esc's for a 1/8 or 1/6th scale.
Our basic 1/16 tank in standard form draws about 1.2amps per side flat-out along the ground with 500gms of ballast. Up hill and in stall conditions this would go up considerably but they really don't use much, my simple run time observation from above seems to concur.
So, our actual POWER is... 7.5v x 1.2A = 9 watts per track x2 =18 watts total. The ancillaries use so little as to be inconsequential.
There is no definitive as everyone drives differently and batteries are not all equal.
Do not bother even keeping NiCads. The technology is so old and their care is so fussy it's just not worth it.
Remember the "memory effect" this is exclusive to NiCads and their energy density is pitiful. I began RC racing in 1983 and that was all we had so I know all of the pitfalls of a a NiCad and there are many.
NiMh cells have had their day in the sun, I still use them and they are a good idea for the standard tank config.
Slow charge rates and bulk are the biggest disadvantage but for all intents and purposes they work well. (remember they are still 1.2v per cell x 6 = 7.2v) They usually only come in the standard "SubC" rendered a standard by the RC car racing community back in the '80's
I'll drop in a truism here that my father imparted many years ago...
"A new item does not render the old one incapable of still doing its job"
So there is nothing wrong with using those old batteries lying around.
Lipo's are here to stay so this next segment is probably of the most interest.
Personally I see the biggest advantage is the ability to use different configuration and sizes to allow for chassis layout optimisation.
A 2.5Ah LiPo with a hard case is smaller than a packet of cigarettes, (not a politically correct simile but I'm sticking with it).
Personally I have been using 18650 cells, they look like a AA on steroids and are the most common LiPo cells in the world.
Most laptop packs are 18650 cells in a series/parallel arrangement, likewise most power tool packs. This is why we see common voltage ranges in most tool marketing (a lot of manufacturers round up to 4.0v per cell as a fully charged LiPo is about 4.15-4.2v).
Elon musk uses these by the 1000's in modular arrangement to drive his legendary TESLA's.
So there we have a cheap source for LiPos without breaking the bank. Most laptop and tool packs fail because 1 cell dies, some manufacturers put a cell count and the battery dies whilst still being perfectly good.
We are not going for hyper performance here, our use is mild and if you can obtain the cells from recycling then you have an ample supply of cheap cells.
Lipos also feature another specification that seems to confuse people
The infamous "C" rating.
Simply put a batteries capacity means the it will deliver its rated voltage at that current for an hour.
The "C" rating is a multiplier of its current that it can deliver continually.
So...
A 7.4v 2500mAh 10c battery will deliver 10 times the rated current in our example 25amps continuous for 6 minutes.
Using the same formula 7.4v 2500mAh 40c battery will give us 100amps for 90 seconds. This is important for racing cars and planes as often a large current surge is needed on acceleration of in the case of planes stunt manoeuvres.
Now you might understand why we often see 80-100 amp ESC in cars and for a 1.2m metre scale warbird a 60-80A ESC is common. They need to deliver very strong bursts of power but again how you drive/fly can drastically effect the runtime of any of these devices.
The effect of not having sufficient capacity or "C rating" feels like the battery is flat. It cannot deliver the required power.
Our tanks have relatively no dynamics in the drivetrain and so a 2000mAh battery of about 8C is all that is really needed.
Having a better rated battery will not hurt but any hi performance LiPo is completely redundant in this application, a battery of 5C is sufficient run a standard chassis.
I'll follow up with some example photos soon (Later tonight if I can).
I just bought some new Battery cradles and will do a tutorial on fitting a 2 cell 18650 holder into a standard chassis, a cheap and effective very simple and cheap upgrade for a standard unit.
To put it simply, the Volts is the power of the battery (how fast it will turn a motor, how brightly it will light a lamp etc).
Amps is how long it will do it for. Unless you're using a lot of amps a big battery (in Mah)is no faster.
It generally corresponds to how long the device will run.
From my limited experience a 2Ah battery will give my about 30-40 minutes of normal "playtime" on my tanks.
A normal "stick pack" that comes with your tank is about 1800-3000 Mah and is usually an arrangement of 6 x 1.2v per cell NiCd or NiMh. Nominally 7.2V for the pack.
Whilst they work fine a LiPo Lithium Polymer pack is much more efficient and compact as well as offering slightly more voltage (3.7v per cell) 2 x 3.7=7.4v.
Using batteries any of higher voltage in a 1/16 tank is a recipe for disaster. The circuits and drivetrain are designed around the 7-8v paradigm and so all of the electronics, and mechanical components are optimised in these ranges. I've done a 12v system for giggles and used a tank mixer with car ESC's. Stripped gear boxes and a thrown track was my reward. It was fast for a while though.
I'd imagine 12v and 30-40A esc's for a 1/8 or 1/6th scale.
Our basic 1/16 tank in standard form draws about 1.2amps per side flat-out along the ground with 500gms of ballast. Up hill and in stall conditions this would go up considerably but they really don't use much, my simple run time observation from above seems to concur.
So, our actual POWER is... 7.5v x 1.2A = 9 watts per track x2 =18 watts total. The ancillaries use so little as to be inconsequential.
There is no definitive as everyone drives differently and batteries are not all equal.
Do not bother even keeping NiCads. The technology is so old and their care is so fussy it's just not worth it.
Remember the "memory effect" this is exclusive to NiCads and their energy density is pitiful. I began RC racing in 1983 and that was all we had so I know all of the pitfalls of a a NiCad and there are many.
NiMh cells have had their day in the sun, I still use them and they are a good idea for the standard tank config.
Slow charge rates and bulk are the biggest disadvantage but for all intents and purposes they work well. (remember they are still 1.2v per cell x 6 = 7.2v) They usually only come in the standard "SubC" rendered a standard by the RC car racing community back in the '80's
I'll drop in a truism here that my father imparted many years ago...
"A new item does not render the old one incapable of still doing its job"
So there is nothing wrong with using those old batteries lying around.
Lipo's are here to stay so this next segment is probably of the most interest.
Personally I see the biggest advantage is the ability to use different configuration and sizes to allow for chassis layout optimisation.
A 2.5Ah LiPo with a hard case is smaller than a packet of cigarettes, (not a politically correct simile but I'm sticking with it).
Personally I have been using 18650 cells, they look like a AA on steroids and are the most common LiPo cells in the world.
Most laptop packs are 18650 cells in a series/parallel arrangement, likewise most power tool packs. This is why we see common voltage ranges in most tool marketing (a lot of manufacturers round up to 4.0v per cell as a fully charged LiPo is about 4.15-4.2v).
Elon musk uses these by the 1000's in modular arrangement to drive his legendary TESLA's.
So there we have a cheap source for LiPos without breaking the bank. Most laptop and tool packs fail because 1 cell dies, some manufacturers put a cell count and the battery dies whilst still being perfectly good.
We are not going for hyper performance here, our use is mild and if you can obtain the cells from recycling then you have an ample supply of cheap cells.
Lipos also feature another specification that seems to confuse people
The infamous "C" rating.
Simply put a batteries capacity means the it will deliver its rated voltage at that current for an hour.
The "C" rating is a multiplier of its current that it can deliver continually.
So...
A 7.4v 2500mAh 10c battery will deliver 10 times the rated current in our example 25amps continuous for 6 minutes.
Using the same formula 7.4v 2500mAh 40c battery will give us 100amps for 90 seconds. This is important for racing cars and planes as often a large current surge is needed on acceleration of in the case of planes stunt manoeuvres.
Now you might understand why we often see 80-100 amp ESC in cars and for a 1.2m metre scale warbird a 60-80A ESC is common. They need to deliver very strong bursts of power but again how you drive/fly can drastically effect the runtime of any of these devices.
The effect of not having sufficient capacity or "C rating" feels like the battery is flat. It cannot deliver the required power.
Our tanks have relatively no dynamics in the drivetrain and so a 2000mAh battery of about 8C is all that is really needed.
Having a better rated battery will not hurt but any hi performance LiPo is completely redundant in this application, a battery of 5C is sufficient run a standard chassis.
I'll follow up with some example photos soon (Later tonight if I can).
I just bought some new Battery cradles and will do a tutorial on fitting a 2 cell 18650 holder into a standard chassis, a cheap and effective very simple and cheap upgrade for a standard unit.
What type of tank, gearbox and track were you running during your 12volts of fun? It would not surprise me that this happened if the gearbox, track, track tension, sprocket, road wheels and suspension were not set up to handle the power output.
I have learned both by research and first hand hard running as it relates to the current Heng Long electronics/motors (and rebrands), that they can easily handle up to 9.6 volts and are rated at almost 11volts. The basic silver motors that come stock with the lower priced tanks run well at 8.4 to 9.6 volts, but wear fast. The better 380 size (black or blue cans) and 390 size motors (commonly red cans) do not really come to life until they are run with at least 8.4volts and there are a number of member here that even run there 390s up to 12volts without any issues (with aftermarket control boards). Yes they get hot and will wear at a faster rate but they are relatively cheap and easy to replace even for those with very basic skills. I switched from 8.4 volt to 9.6 volts six months ago and have been running them for many hard hours since and have yet to see any degradation in electronics or motor performance. Unfortunately these volt levels are not available in LiPos so I am stuck running NiMh batteries which is not a big issue for my larger modern tank hulls to fit.
Last edited by Fsttanks; 07-11-2018 at 10:44 AM.
07-11-2018, 10:47 AM
#13
Just a note on battery types.
While I agree Lipo is the way of the future, NiMH works wonderfully too.
And for NiCd, I never found the 'fussy' issues mentioned except memory effect if not completely cycled.
One consideration to battery choice is capacity is really not critical, as the nature of tank simulation/battling is sporatic movement, not constant like racing.
A 50-60% duty cycle is more realistic for tank driving, where the motor RPM is fairly constant (because of the gear ratio).
My experience in the past with NiCd for instance, is 30 minutes on a 1500 pack, battling, not bad for a NiCd.
While I agree Lipo is the way of the future, NiMH works wonderfully too.
And for NiCd, I never found the 'fussy' issues mentioned except memory effect if not completely cycled.
One consideration to battery choice is capacity is really not critical, as the nature of tank simulation/battling is sporatic movement, not constant like racing.
A 50-60% duty cycle is more realistic for tank driving, where the motor RPM is fairly constant (because of the gear ratio).
My experience in the past with NiCd for instance, is 30 minutes on a 1500 pack, battling, not bad for a NiCd.
07-11-2018, 10:57 AM
#14
Personally I use lipos exclusively in everything I have. However most of the stock systems available are not setup for lipos at this time and run the voltage down way lower than you want on a 2S lipo. In fact I've seen some controllers run down to 6V or lower for the NIMH batteries. I suggest to all who wish to run lipo either do one of these two things:
There are all kinds of shipping restrictions on lipos and storage for them is pretty scary here in FL. They are much more temperamental when it comes to storage than NIMHs and heat. The last thing I worry about is safety. WOW would you guys be surprised at some of the stories I hear haha. In fact a pretty large hobby store burnt down about a year ago due to one of the "techs" charging a lipo as a NIMH to recover it a few volts so he could charge it correctly. He wasn't paying attention just for a minute or two and the whole store burnt down. One thing good I can say about the NIMH batteries.... they are pretty darn safe albeit a bit weak sometimes. To each his own though, those lipos can be super dense and great to work with if you know your stuff.
- Run a simple LVA (low voltage alarm) off your balance leads. Make sure the beeper is super loud and that you aren't too far away.
- Better yet, run an aftermarket system that allows you to send battery voltage telemetry back (like FRSky and FlySky) and monitor it from your transmitter.
There are all kinds of shipping restrictions on lipos and storage for them is pretty scary here in FL. They are much more temperamental when it comes to storage than NIMHs and heat. The last thing I worry about is safety. WOW would you guys be surprised at some of the stories I hear haha. In fact a pretty large hobby store burnt down about a year ago due to one of the "techs" charging a lipo as a NIMH to recover it a few volts so he could charge it correctly. He wasn't paying attention just for a minute or two and the whole store burnt down. One thing good I can say about the NIMH batteries.... they are pretty darn safe albeit a bit weak sometimes. To each his own though, those lipos can be super dense and great to work with if you know your stuff.
07-12-2018, 03:01 AM
#15
Thread Starter
Join Date: Jul 2018
Posts: 44
Likes: 0
Received 0 Likes
on
0 Posts
I am roughing out a chapter on Radio protocols and modifying to use a standard Hobby grade transmitter.
Do you think I should begin a different thread for each of these subjects?
I think the battery segment may elicit questions that deserve a thread all by themselves.
The radio solutions can be very intricate but I'm going to try and address the essential "tank centric" issues and demonstrate some advantages of using a 6-8ch radio and I'm hoping to get my hands on a FS-6 and modify it with centring on the throttle for tank specific use.
This radio seems to be born for for this hobby.
I will probably try to work with OpenPanzer on this as I see an integrated Hi-End option pack based on the OP and this radio.
I've also been playing with a
iRangeX IRX4 Plus 2.4G 4 IN 1 Multiprotocol STM32 TX Module
This allows my radio to emulate 90% of the 2.4Ghz protocols out there so I can control almost any device from one radio.
I'm going to play with this a bit and enlist the help of many other forums and their specialist users to summarise this here.
I will say that the RC5HL is the best tool I’ve ever seen to make the hobby attainable.
Ah Ha my dear friend Arctic Cat. you seem to have read my mind.
My initial Battery post was of course a basic intro into battery chemistry and relevance.
Most particularly into the power requirements of a good 1/16 tank.
Of course there are are specific nuances that apply to any battery technology and I’ll also address any specific requirements for NiMh as well if people ask. We can do pB and solar for the big scale guys if you really need to go there. I have a solar wheelbarrow that is so cool.
Pt 2 was to be a specific rant on the way to use the technologies properly.
Charging, use and storage are of course important for any item that is capable of the explosive consumption and dumping over 12hp of energy in less than a second, in a package that is smaller than an iPhone. Anything with that sort of potential deserves respect, Lipos more so, because a short circuit can trigger a breakdown that can be catastrophic.
Plastic tanks and massive thermal breakdown will result in a puddle of melted plastic.
I saw that once when a Corvette caught fire, that was just so sad.
I will go into low voltage issues and over current charging but unless you try to do a better than a 5 minute charge (12C) on a 2500 mAh battery they are pretty safe.
Millions of laptops and smartphones use this tech with impunity, by and large the issues are for extreme usage and outside the purview of of the tanker requirements.
Thanks for the Kudos .
I was using an old original TX-13 equipped Pershing that was stock. I was under no illusion that something wasn’t going to break, it was an exercise in testing the parameters of the stock drivetrain.
I agree that the electronics will run at 11 volts though I am unsure of the durability and I wouldn’t do it. There are too many ways to avoid over voltage to risk it. If you need to use higher voltage then you’ve modified to the point where the stock controller is redundant anyway. Spring some coin and get a set of proper upgraded electronics. A standard fully charged 2s LiPo is essentially 7.8-8v anyway so it’s a power upgrade from the get go.
You also seemed to miss the original idea that was to offer simple upgrade options for entry level type users.
The 380 and 390 motors are meant to be used with 12 volts (though there are 6v versions available) and a steel geared gearbox with metal drive wheels and tracks will obviously cope with substantially more than the original hardware but that is getting into the realm of super modified. This is moving away from the original premise again and anyone prepared to drop $3-400 on a drivetrain is going to be dropping some coin in the other areas as well. Usually with aftermarket control units etc. Do not transpose voltage for current. A 390 uses nearly twice the current of a 380 and this kills ESCs’.
I will be moving to 390’s in everything myself as they offer considerably more torque than 380’s. In much the same way as 550 motors are used in 4wd 1/10th trucks as opposed to the ubiquitous 540 in just about everything else. Torque is more important in tracked armour.
Input capacitors on the ESC's will give added initial punch if required. and a limiting circuit on the electronics input can tame the supply voltage to the electronics. Everyone who flies serious planes uses 2 batteries, one for the electronics, but for something that doesn't fall out of the sky when it stops, I would be using a 6v UBEC on the electronics and feeding the 12V to the drivetrain, best of both worlds.
Whilst this is outside the purview of the original post I shall do a simple "how to" on using a UBEC to allow split voltages with aftermarket hardware for those that must have the punch of over voltage or are pushing full metal rigs where a 12v system does make perfect sense. To bring the speed down just set the throttle end points to 75-85% so you can emulate true scale speeds, 4km/h would be about right for most historic armour which is a moderate walking pace, modern armour, a brisk walking pace, 6km/h is about right.
I am trying to get away from discussions of the minutiae and offer more broad solutions to make the hobby more accessible, not make the best hot rod, puppy killing armour in the world. History has shown that the elitists kill hobbies faster than the marketing people. It becomes so competitive that even to ask a question seems daunting and belittling.
It’s really all about the fun, not taking oneself too seriously. Believe me, I can get SO hardcore that getting 30-40 km/h from a tank is really no big ask. For how long? I’m not going there. When you start pushing the limits you just keep moving the weak point until something else fails, eventually you settle for something that will last. To make an extensible, easy to use platform for historians, enthusiasts and Doggy hunters seems a far better use of my resources in my humble opinion.
If you're happy then that's just great.
I haven't used a NiCd for 15 years and have no desire to combat the issues again. (Pun intended)
Battery technology has moved so far forward. I agree and did make a point that the duty cycle and usage in tracked armour is slight by comparison with most other forms of RC.
I get 30-40 minutes of Doggy hunting from a set of 18650 batteries I rescued from a tool pack and they are, as the name suggests, just 18mm in diameter and 65mm long. They use less then 1/3 of the battery bay.
A NiMh pack is a valid solution just not a way to go forward with modified layouts and larger motors. There are just more options available with a LiPo solution.
There is no setup change needed to move to a 2s LiPo solution except mounting the batteries and a connector. The voltages are close enough to be of no consequence. You can include a low voltage cut off if you think you may need one, personally when it gets slower I come home and change the battery.
I agree with the need to be diligent and aware but as you stated, the accident you mentioned was the result of misuse and probably ignorance by the tech.
I have used the procedure you mentioned to recover cells but being aware of the issues, used a specific area and monitored the procedure. It works sometimes. Don't tell me you haven't seen an NiMh pack explode due to unsupervised charging or failed equipment, the results can be just as catastrophic. Nearly every issue I’ve seen has been high energy packs being pushed to the limit or abused in competition environments. Or just idiots. As soon as you make something idiot proof we seem to generate a new level of idiots. I intend to minimise these issues by education. I cannot protect someone from themselves.
In scale armour the battery is not a critical component, it just provides motive power in a very steady and controlled way.
This is why I went the 18650 route, simple, stable, cheap, neat and reliable. Just what’s required so you can get on with countering those cunning Basset Hound tactics.
I won't agree that they are any more temperamental than NiCd/NiMhs just different. Back in the day there were all sorts of rituals to optimise packs that make the LiPo procedures seem simple. (That makes me feel SO old ) Whilst you also don't have to worry about the self discharge either. You can run a LiPo down to 2.8V/cell with little chance of damage actually. Most use 3.3v or so for a safety margin. There are a lot of protection circuits available for about a dollar that cure this easily.
I have an idea for a Low voltage alarm led that can be fitted anywhere on the hull that would give a visual sign without compromising the scale look very much, just the nub of a 3mm led poking out of the hull wherever is practicable.
My Radio rant will address Telemetry and FPV as well as multi-protocol systems, modifying for ground system specific handsets, and updated firmware that continues the idea of the original “TANKERx”, a good idea but a bit overcomplicated for most users at the time.
As for the heat issue I haven’t found that to be the case. Both chemistries are adversely affected by extremes in temperature but LiPos have developed to the point where I would consider them to be the more stable option.
I live in Australia where summers are regularly 100F and winters down to 20F daytime. (40C and -4C)
I use a bank of LiFePo4 (Lithium iron phosphate) cells as the battery in my motorcycle. These are more stable and are the weapon of choice in serious solar and wind generator systems. They are of a slightly lower nominal voltage than LiPos (3.3v/cell) but have a similar energy density. They lend themselves most perfectly to the “deep cycle” type of environments.
The fact remains that Lithium Chemistry is here and is the default storage in tens of millions of electronic devices and, as you will see in some future articles, all of these issues are easily addressed and that, by and large, a LiPo is a simpler, more compact and more effective solution. Like a lot of things they get simpler with familiarity.
These questions are exactly the reason I began this series of posts. Thank you all, keep challenging me as I can’t consider all angles from my limited insights, we learn by listening and teach with examples.
I mean to consolidate the battery myths and address any issues, whether Nickel or Lithium chemistry to maximise the Doggy stalking and minimise the fuss about batteries.
You will find that there are many potential arrangements which are all valid in the environment in which they are employed. My aim is to be resource that can offer an educated opinion without judgement to simplify one of the weak points in many hobbyists armour (pun intended). I offer the 18650 solution as an almost free solution that can be done with minimal tools and offers more runtime and slightly more power for an entry level Doggy hunter. The issue that seems most prevalent is that people transpose and confuse voltage and current. They are all ingredients of the same pizza but cheese is not pepperoni. Voltage is the toppings and amps is the family vs a single slice.
Well done to all of you by throwing some valid and pertinent issues that I’ll address more specifically in individual posts.
It seems that due to my amateur status on these forums I am limited to 5 posts in any 24 hr period (edits included) and I cannot post a URL until I’ve earned my chops.
Absence makes the heart grow fonder…
Smooth Roads
Bill
P.S.
My dogs hate all of you.
I breed pedigree Basset Hounds (the Maytag dog) as well as support an insufferable addiction to gizmos.
Do you think I should begin a different thread for each of these subjects?
I think the battery segment may elicit questions that deserve a thread all by themselves.
The radio solutions can be very intricate but I'm going to try and address the essential "tank centric" issues and demonstrate some advantages of using a 6-8ch radio and I'm hoping to get my hands on a FS-6 and modify it with centring on the throttle for tank specific use.
This radio seems to be born for for this hobby.
I will probably try to work with OpenPanzer on this as I see an integrated Hi-End option pack based on the OP and this radio.
I've also been playing with a
iRangeX IRX4 Plus 2.4G 4 IN 1 Multiprotocol STM32 TX Module
This allows my radio to emulate 90% of the 2.4Ghz protocols out there so I can control almost any device from one radio.
I'm going to play with this a bit and enlist the help of many other forums and their specialist users to summarise this here.
I will say that the RC5HL is the best tool I’ve ever seen to make the hobby attainable.
Good write up for the batteries. Coming from RC Crawlers and on-road cars its surprising how few people seem to use Lipos in tanks considering how popular they are in other RC segments. Seems to be a lot of mis-information on them floating around. One thing that you did not mention about them though is proper use and storage which is the key for staying safe. Things such as fireproof storage/charging area, making sure not to over discharge or over charge, storage voltage, visual inspection for general condition, proper balance charger and finally disposal. Long story short if you follow best practices for Lipos they are a great battery technology to use.
My initial Battery post was of course a basic intro into battery chemistry and relevance.
Most particularly into the power requirements of a good 1/16 tank.
Of course there are are specific nuances that apply to any battery technology and I’ll also address any specific requirements for NiMh as well if people ask. We can do pB and solar for the big scale guys if you really need to go there. I have a solar wheelbarrow that is so cool.
Pt 2 was to be a specific rant on the way to use the technologies properly.
Charging, use and storage are of course important for any item that is capable of the explosive consumption and dumping over 12hp of energy in less than a second, in a package that is smaller than an iPhone. Anything with that sort of potential deserves respect, Lipos more so, because a short circuit can trigger a breakdown that can be catastrophic.
Plastic tanks and massive thermal breakdown will result in a puddle of melted plastic.
I saw that once when a Corvette caught fire, that was just so sad.
I will go into low voltage issues and over current charging but unless you try to do a better than a 5 minute charge (12C) on a 2500 mAh battery they are pretty safe.
Millions of laptops and smartphones use this tech with impunity, by and large the issues are for extreme usage and outside the purview of of the tanker requirements.
Good write up for basic battery types and power outputs.
What type of tank, gearbox and track were you running during your 12volts of fun? It would not surprise me that this happened if the gearbox, track, track tension, sprocket, road wheels and suspension were not set up to handle the power output.
I have learned both by research and first hand hard running as it relates to the current Heng Long electronics/motors (and rebrands), that they can easily handle up to 9.6 volts and are rated at almost 11volts. The basic silver motors that come stock with the lower priced tanks run well at 8.4 to 9.6 volts, but wear fast. The better 380 size (black or blue cans) and 390 size motors (commonly red cans) do not really come to life until they are run with at least 8.4volts and there are a number of member here that even run there 390s up to 12volts without any issues (with aftermarket control boards). Yes they get hot and will wear at a faster rate but they are relatively cheap and easy to replace even for those with very basic skills. I switched from 8.4 volt to 9.6 volts six months ago and have been running them for many hard hours since and have yet to see any degradation in electronics or motor performance. Unfortunately these volt levels are not available in LiPos so I am stuck running NiMh batteries which is not a big issue for my larger modern tank hulls to fit.
What type of tank, gearbox and track were you running during your 12volts of fun? It would not surprise me that this happened if the gearbox, track, track tension, sprocket, road wheels and suspension were not set up to handle the power output.
I have learned both by research and first hand hard running as it relates to the current Heng Long electronics/motors (and rebrands), that they can easily handle up to 9.6 volts and are rated at almost 11volts. The basic silver motors that come stock with the lower priced tanks run well at 8.4 to 9.6 volts, but wear fast. The better 380 size (black or blue cans) and 390 size motors (commonly red cans) do not really come to life until they are run with at least 8.4volts and there are a number of member here that even run there 390s up to 12volts without any issues (with aftermarket control boards). Yes they get hot and will wear at a faster rate but they are relatively cheap and easy to replace even for those with very basic skills. I switched from 8.4 volt to 9.6 volts six months ago and have been running them for many hard hours since and have yet to see any degradation in electronics or motor performance. Unfortunately these volt levels are not available in LiPos so I am stuck running NiMh batteries which is not a big issue for my larger modern tank hulls to fit.
.I was using an old original TX-13 equipped Pershing that was stock. I was under no illusion that something wasn’t going to break, it was an exercise in testing the parameters of the stock drivetrain.
I agree that the electronics will run at 11 volts though I am unsure of the durability and I wouldn’t do it. There are too many ways to avoid over voltage to risk it. If you need to use higher voltage then you’ve modified to the point where the stock controller is redundant anyway. Spring some coin and get a set of proper upgraded electronics. A standard fully charged 2s LiPo is essentially 7.8-8v anyway so it’s a power upgrade from the get go.
You also seemed to miss the original idea that was to offer simple upgrade options for entry level type users.
The 380 and 390 motors are meant to be used with 12 volts (though there are 6v versions available) and a steel geared gearbox with metal drive wheels and tracks will obviously cope with substantially more than the original hardware but that is getting into the realm of super modified. This is moving away from the original premise again and anyone prepared to drop $3-400 on a drivetrain is going to be dropping some coin in the other areas as well. Usually with aftermarket control units etc. Do not transpose voltage for current. A 390 uses nearly twice the current of a 380 and this kills ESCs’.
I will be moving to 390’s in everything myself as they offer considerably more torque than 380’s. In much the same way as 550 motors are used in 4wd 1/10th trucks as opposed to the ubiquitous 540 in just about everything else. Torque is more important in tracked armour.
Input capacitors on the ESC's will give added initial punch if required. and a limiting circuit on the electronics input can tame the supply voltage to the electronics. Everyone who flies serious planes uses 2 batteries, one for the electronics, but for something that doesn't fall out of the sky when it stops, I would be using a 6v UBEC on the electronics and feeding the 12V to the drivetrain, best of both worlds.
Whilst this is outside the purview of the original post I shall do a simple "how to" on using a UBEC to allow split voltages with aftermarket hardware for those that must have the punch of over voltage or are pushing full metal rigs where a 12v system does make perfect sense. To bring the speed down just set the throttle end points to 75-85% so you can emulate true scale speeds, 4km/h would be about right for most historic armour which is a moderate walking pace, modern armour, a brisk walking pace, 6km/h is about right.
I am trying to get away from discussions of the minutiae and offer more broad solutions to make the hobby more accessible, not make the best hot rod, puppy killing armour in the world. History has shown that the elitists kill hobbies faster than the marketing people. It becomes so competitive that even to ask a question seems daunting and belittling.
It’s really all about the fun, not taking oneself too seriously. Believe me, I can get SO hardcore that getting 30-40 km/h from a tank is really no big ask. For how long? I’m not going there. When you start pushing the limits you just keep moving the weak point until something else fails, eventually you settle for something that will last. To make an extensible, easy to use platform for historians, enthusiasts and Doggy hunters seems a far better use of my resources in my humble opinion.
Just a note on battery types.
While I agree Lipo is the way of the future, NiMH works wonderfully too.
And for NiCd, I never found the 'fussy' issues mentioned except memory effect if not completely cycled.
One consideration to battery choice is capacity is really not critical, as the nature of tank simulation/battling is sporatic movement, not constant like racing.
A 50-60% duty cycle is more realistic for tank driving, where the motor RPM is fairly constant (because of the gear ratio).
My experience in the past with NiCd for instance, is 30 minutes on a 1500 pack, battling, not bad for a NiCd.
While I agree Lipo is the way of the future, NiMH works wonderfully too.
And for NiCd, I never found the 'fussy' issues mentioned except memory effect if not completely cycled.
One consideration to battery choice is capacity is really not critical, as the nature of tank simulation/battling is sporatic movement, not constant like racing.
A 50-60% duty cycle is more realistic for tank driving, where the motor RPM is fairly constant (because of the gear ratio).
My experience in the past with NiCd for instance, is 30 minutes on a 1500 pack, battling, not bad for a NiCd.
I haven't used a NiCd for 15 years and have no desire to combat the issues again. (Pun intended)
Battery technology has moved so far forward. I agree and did make a point that the duty cycle and usage in tracked armour is slight by comparison with most other forms of RC.
I get 30-40 minutes of Doggy hunting from a set of 18650 batteries I rescued from a tool pack and they are, as the name suggests, just 18mm in diameter and 65mm long. They use less then 1/3 of the battery bay.
A NiMh pack is a valid solution just not a way to go forward with modified layouts and larger motors. There are just more options available with a LiPo solution.
Personally I use lipos exclusively in everything I have. However most of the stock systems available are not setup for lipos at this time and run the voltage down way lower than you want on a 2S lipo. In fact I've seen some controllers run down to 6V or lower for the NIMH batteries. I suggest to all who wish to run lipo either do one of these two things: There are all kinds of shipping restrictions on lipos and storage for them is pretty scary here in FL. They are much more temperamental when it comes to storage than NIMHs and heat. The last thing I worry about is safety. WOW would you guys be surprised at some of the stories I hear haha. In fact a pretty large hobby store burnt down about a year ago due to one of the "techs" charging a lipo as a NIMH to recover it a few volts so he could charge it correctly. He wasn't paying attention just for a minute or two and the whole store burnt down. One thing good I can say about the NIMH batteries.... they are pretty darn safe albeit a bit weak sometimes. To each his own though, those lipos can be super dense and great to work with if you know your stuff.
- Run a simple LVA (low voltage alarm) off your balance leads. Make sure the beeper is super loud and that you aren't too far away.
- Better yet, run an aftermarket system that allows you to send battery voltage telemetry back (like FRSky and FlySky) and monitor it from your transmitter.
There are all kinds of shipping restrictions on lipos and storage for them is pretty scary here in FL. They are much more temperamental when it comes to storage than NIMHs and heat. The last thing I worry about is safety. WOW would you guys be surprised at some of the stories I hear haha. In fact a pretty large hobby store burnt down about a year ago due to one of the "techs" charging a lipo as a NIMH to recover it a few volts so he could charge it correctly. He wasn't paying attention just for a minute or two and the whole store burnt down. One thing good I can say about the NIMH batteries.... they are pretty darn safe albeit a bit weak sometimes. To each his own though, those lipos can be super dense and great to work with if you know your stuff.I agree with the need to be diligent and aware but as you stated, the accident you mentioned was the result of misuse and probably ignorance by the tech.
I have used the procedure you mentioned to recover cells but being aware of the issues, used a specific area and monitored the procedure. It works sometimes. Don't tell me you haven't seen an NiMh pack explode due to unsupervised charging or failed equipment, the results can be just as catastrophic. Nearly every issue I’ve seen has been high energy packs being pushed to the limit or abused in competition environments. Or just idiots. As soon as you make something idiot proof we seem to generate a new level of idiots. I intend to minimise these issues by education. I cannot protect someone from themselves.
In scale armour the battery is not a critical component, it just provides motive power in a very steady and controlled way.
This is why I went the 18650 route, simple, stable, cheap, neat and reliable. Just what’s required so you can get on with countering those cunning Basset Hound tactics.
I won't agree that they are any more temperamental than NiCd/NiMhs just different. Back in the day there were all sorts of rituals to optimise packs that make the LiPo procedures seem simple. (That makes me feel SO old
) Whilst you also don't have to worry about the self discharge either. You can run a LiPo down to 2.8V/cell with little chance of damage actually. Most use 3.3v or so for a safety margin. There are a lot of protection circuits available for about a dollar that cure this easily.I have an idea for a Low voltage alarm led that can be fitted anywhere on the hull that would give a visual sign without compromising the scale look very much, just the nub of a 3mm led poking out of the hull wherever is practicable.
My Radio rant will address Telemetry and FPV as well as multi-protocol systems, modifying for ground system specific handsets, and updated firmware that continues the idea of the original “TANKERx”, a good idea but a bit overcomplicated for most users at the time.
As for the heat issue I haven’t found that to be the case. Both chemistries are adversely affected by extremes in temperature but LiPos have developed to the point where I would consider them to be the more stable option.
I live in Australia where summers are regularly 100F and winters down to 20F daytime. (40C and -4C)
I use a bank of LiFePo4 (Lithium iron phosphate) cells as the battery in my motorcycle. These are more stable and are the weapon of choice in serious solar and wind generator systems. They are of a slightly lower nominal voltage than LiPos (3.3v/cell) but have a similar energy density. They lend themselves most perfectly to the “deep cycle” type of environments.
The fact remains that Lithium Chemistry is here and is the default storage in tens of millions of electronic devices and, as you will see in some future articles, all of these issues are easily addressed and that, by and large, a LiPo is a simpler, more compact and more effective solution. Like a lot of things they get simpler with familiarity.
These questions are exactly the reason I began this series of posts. Thank you all, keep challenging me as I can’t consider all angles from my limited insights, we learn by listening and teach with examples.
I mean to consolidate the battery myths and address any issues, whether Nickel or Lithium chemistry to maximise the Doggy stalking and minimise the fuss about batteries.
You will find that there are many potential arrangements which are all valid in the environment in which they are employed. My aim is to be resource that can offer an educated opinion without judgement to simplify one of the weak points in many hobbyists armour (pun intended). I offer the 18650 solution as an almost free solution that can be done with minimal tools and offers more runtime and slightly more power for an entry level Doggy hunter. The issue that seems most prevalent is that people transpose and confuse voltage and current. They are all ingredients of the same pizza but cheese is not pepperoni. Voltage is the toppings and amps is the family vs a single slice.
Well done to all of you by throwing some valid and pertinent issues that I’ll address more specifically in individual posts.
It seems that due to my amateur status on these forums I am limited to 5 posts in any 24 hr period (edits included) and I cannot post a URL until I’ve earned my chops.
Absence makes the heart grow fonder…
Smooth Roads
Bill
P.S.
My dogs hate all of you.
I breed pedigree Basset Hounds (the Maytag dog) as well as support an insufferable addiction to gizmos.
Last edited by Brycevr; 07-12-2018 at 04:00 AM.
07-12-2018, 04:14 AM
#16
Thread Starter
Join Date: Jul 2018
Posts: 44
Likes: 0
Received 0 Likes
on
0 Posts
Why do I have a status of premium vendor and still cannot post URL's or more the 5 posts in a day?
I'm not a vendor and for all intents and purposes on this forum I am a rank amateur.
What do these badges of honour really mean?
Should I care?
It doesn't seem to make a lot of difference, not that I really care but , REALLY, what's the point. I'm happy enough with myself to not require outside endorsements. I know who I am and what I can do, I am here because I want to be.
I would probably think the rank of "smart ass" is a more relevant title.
and I just wasted one of my 5 valuable postings by being a smart ass...
I'm not a vendor and for all intents and purposes on this forum I am a rank amateur.
What do these badges of honour really mean?
Should I care?
It doesn't seem to make a lot of difference, not that I really care but , REALLY, what's the point. I'm happy enough with myself to not require outside endorsements. I know who I am and what I can do, I am here because I want to be.
I would probably think the rank of "smart ass" is a more relevant title.
and I just wasted one of my 5 valuable postings by being a smart ass...
Last edited by Brycevr; 07-12-2018 at 04:19 AM.
07-12-2018, 05:04 AM
#18
Join Date: Feb 2015
Location: Alexandria, Minnesota, USA
Posts: 493
Received 0 Likes
on
0 Posts
Bill,
My vote would be to separate your educational posts.
For me, its easier to go back and read up on a subject if has mostly the same context in it.
Battery thread, transmitter thread, receiver thread, etc. Some may need more than 1 thread, like a beginners thread, and and advanced user thread.
just my opinion.
Enjoy,
Shad
My vote would be to separate your educational posts.
For me, its easier to go back and read up on a subject if has mostly the same context in it.
Battery thread, transmitter thread, receiver thread, etc. Some may need more than 1 thread, like a beginners thread, and and advanced user thread.
just my opinion.
Enjoy,
Shad
07-12-2018, 05:31 AM
#19
Thread Starter
Join Date: Jul 2018
Posts: 44
Likes: 0
Received 0 Likes
on
0 Posts
Yeah I see where you come from.
I have been doing RC at championship levels in electric and nitro and used to work as development engineer when the logo was 6 colours.
I get ahead of myself.
All of these issues are in and of themselves unique studies, worthy of many chapters in any tome of information.
I am trying here to pare down the plethora of info into that that pertains to 1/16 tracked armour. ( I really like that I used "that that" I've NEVER used that sequence before, SO COOL from an etymological perspective) and it was grammatically correct. Meanwhile back to our usual programming...
I toyed with different systems many years ago and found everyone had a good idea but it didn't match someone else's good idea and it all stalled.
I think I might edit my posts into specific areas as already my meagre battery posts has proffered some challenges. I dread the issues that multi platform radio sequencing might return my other issue is that conversation and to and fro dilutes the message so I hope that down the track (that one was just too punny) I might consolidate a sticky that provides a go to for most issues.
We'll see where it goes, these things seem to generate their own space .
I'm still chuffed about "that that"
I have been doing RC at championship levels in electric and nitro and used to work as development engineer when the logo was 6 colours.
I get ahead of myself.
All of these issues are in and of themselves unique studies, worthy of many chapters in any tome of information.
I am trying here to pare down the plethora of info into that that pertains to 1/16 tracked armour. ( I really like that I used "that that" I've NEVER used that sequence before, SO COOL from an etymological perspective) and it was grammatically correct. Meanwhile back to our usual programming...
I toyed with different systems many years ago and found everyone had a good idea but it didn't match someone else's good idea and it all stalled.
I think I might edit my posts into specific areas as already my meagre battery posts has proffered some challenges. I dread the issues that multi platform radio sequencing might return
my other issue is that conversation and to and fro dilutes the message so I hope that down the track (that one was just too punny) I might consolidate a sticky that provides a go to for most issues.We'll see where it goes, these things seem to generate their own space .
I'm still chuffed about "that that"
Last edited by Brycevr; 07-12-2018 at 06:51 AM.
07-13-2018, 03:17 AM
#20
Thread Starter
Join Date: Jul 2018
Posts: 44
Likes: 0
Received 0 Likes
on
0 Posts
It appears that not only have I been vindicated but in fact my 18650 solution is used by Heng Long themselves.
A new M41A3 turned up today with a battery housing that is the same shape as a 6cell pack with a LiPo label.
When I split the cases it held a pair of 18650 cells.
Here's my solution...
And here is what Heng Long provide
They just put theirs in a familiar case.
Mine allows to swap the cells out and use a generic 18650 charger.
I rest my case.
Mine was $1.20 for the housing and as I use XT30 connectors that's another dollar and rescued cells from a tool pack that are in fact better rated than the HL ones.
So, to convert.
$2.20 and some rescued cells.
If you luck on a premium tool pack then you might even end up with a 2500mAh pack.
The generic cells that I'm using here are 2200mAh Samsung cells and have been perfect through 20-30 cycles so far so I can't see any reason why they won't meet their 1200 cycle duty as they came from a leaf blower with a burned out motor that had been used about 4 times and put on a shelf until the warranty had run out.
This pack gave me 10 cells so I could charge them all and drive my tank for over 2 1/2 hours and if I carried a charger, all day. You can charge at 4C so 20-30 minutes per pair of cells or even 4 at once if you have a reasonable charger.
Money for old rope.
A new M41A3 turned up today with a battery housing that is the same shape as a 6cell pack with a LiPo label.
When I split the cases it held a pair of 18650 cells.
Here's my solution...
And here is what Heng Long provide
They just put theirs in a familiar case.
Mine allows to swap the cells out and use a generic 18650 charger.
I rest my case.
Mine was $1.20 for the housing and as I use XT30 connectors that's another dollar and rescued cells from a tool pack that are in fact better rated than the HL ones.
So, to convert.
$2.20 and some rescued cells.
If you luck on a premium tool pack then you might even end up with a 2500mAh pack.
The generic cells that I'm using here are 2200mAh Samsung cells and have been perfect through 20-30 cycles so far so I can't see any reason why they won't meet their 1200 cycle duty as they came from a leaf blower with a burned out motor that had been used about 4 times and put on a shelf until the warranty had run out.
This pack gave me 10 cells so I could charge them all and drive my tank for over 2 1/2 hours and if I carried a charger, all day. You can charge at 4C so 20-30 minutes per pair of cells or even 4 at once if you have a reasonable charger.
Money for old rope.
Last edited by Brycevr; 07-13-2018 at 04:01 AM.
07-13-2018, 04:53 AM
#22
Thread Starter
Join Date: Jul 2018
Posts: 44
Likes: 0
Received 0 Likes
on
0 Posts
It's a $3 solution
You can get the cradles here
18650 Battery holders
These will allow you to screw the holder to the roof of the battery chamber as they have screw mount points between the cells as opposed to some of the others that have the mounting holes under the cells which may rub against the cells and cause issues. Even good quality double sided tape would suffice.
I just love double sided tape, there are so many different types that all have their places in the world like the 3M stuff I use to repair iPhones and the spongy stuff for ESC mounting and the gummy stuff that just won't let go etc. I'd use the green backed spongy stuff, and try and cover about 50% of the battery carrier, or just use screws and some tape.
Any 20AWG or 18AWG wire is more than sufficient. Remember we only draw about 4 Amps going full tilt boogie with a standard tank. Try and get high core count silicone as it is so much more durable and flexible and for the few bucks it's probably a good move. If you're like me and broke most of the time then rob an old PC power supply, the leads are long enough and the only real downside is that they are a bit stiff, they are more than up to the task.
I use XT30 connectors, though since I have a lot of deans connectors I do use them sometimes.
You can of course continue with the Tamiya connectors but I see these as redundant as NiCads.
Just bridge one end and you have a 7.4V LiPo in your doggy stalker. Remember to alternate the cells. one side +ve up and the other -ve up. they must add the cells in a row.
A pair of 3.7V LiPos in series. a 5% power upgrade and a more convenient format.
I'll do a set of tutorials for using a 12V 3S1P setup and also for 1hr runtimes or high current usage using a 2S2P 2 series 2 parallel setup where by doubling up we'll get twice the storage and twice the available current.
If you'd like this with pictures etc then just let me know.
Now you don't have to ride a horse to work ...
18650 Battery holders
These will allow you to screw the holder to the roof of the battery chamber as they have screw mount points between the cells as opposed to some of the others that have the mounting holes under the cells which may rub against the cells and cause issues. Even good quality double sided tape would suffice.
I just love double sided tape, there are so many different types that all have their places in the world like the 3M stuff I use to repair iPhones and the spongy stuff for ESC mounting and the gummy stuff that just won't let go etc. I'd use the green backed spongy stuff, and try and cover about 50% of the battery carrier, or just use screws and some tape.
Any 20AWG or 18AWG wire is more than sufficient. Remember we only draw about 4 Amps going full tilt boogie with a standard tank. Try and get high core count silicone as it is so much more durable and flexible and for the few bucks it's probably a good move. If you're like me and broke most of the time then rob an old PC power supply, the leads are long enough and the only real downside is that they are a bit stiff, they are more than up to the task.
I use XT30 connectors, though since I have a lot of deans connectors I do use them sometimes.
You can of course continue with the Tamiya connectors but I see these as redundant as NiCads.
Just bridge one end and you have a 7.4V LiPo in your doggy stalker. Remember to alternate the cells. one side +ve up and the other -ve up. they must add the cells in a row.
A pair of 3.7V LiPos in series. a 5% power upgrade and a more convenient format.
I'll do a set of tutorials for using a 12V 3S1P setup and also for 1hr runtimes or high current usage using a 2S2P 2 series 2 parallel setup where by doubling up we'll get twice the storage and twice the available current.
If you'd like this with pictures etc then just let me know.
Now you don't have to ride a horse to work ...
Last edited by Brycevr; 07-13-2018 at 05:38 AM. Reason: It's a $3 solution
07-13-2018, 05:13 AM
#23
I am really awaiting the production of water based Li-po as that technology is stable and not combustible.
I had a Li-po flame up on me from charging, once the chemical reaction starts it can't be stopped.
With the advent of kids in this hobby, I would only trust a non-combusible battery type.
I had a Li-po flame up on me from charging, once the chemical reaction starts it can't be stopped.
With the advent of kids in this hobby, I would only trust a non-combusible battery type.
07-13-2018, 05:49 AM
#24
Thread Starter
Join Date: Jul 2018
Posts: 44
Likes: 0
Received 0 Likes
on
0 Posts
I am really awaiting the production of water based Li-po as that technology is stable and not combustible.
I had a Li-po flame up on me from charging, once the chemical reaction starts it can't be stopped.
With the advent of kids in this hobby, I would only trust a non-combusible battery type.
I had a Li-po flame up on me from charging, once the chemical reaction starts it can't be stopped.
With the advent of kids in this hobby, I would only trust a non-combusible battery type.
You must have had a dead short somewhere.
I've abused LiPos beyond any reasonable constraint and have only managed to violently trash 2. Both from dropping excess solder whilst reconfiguring packs. I run some serious HP in packs, my Sopwith pulls as much grunt as a brush cutter engine using a5s2P pack at 6Ah. My Spit uses a 6S2P with 8Ah, thats over 4HP from a cell pack, most lawnmowers don't have that much grunt. If you think that I am not scared by this level of compacted energy you'd be wrong. I just went out of my way to understand it enough to respect it properly.
If you're not cool with lithium based storage then best throw away the iPad, iPod, iPhone, Laptop, GPS, and whatever android device you're currently carrying around in your pocket, god knows what else.
I would suspect you're issue was poor equipment not poor tech.
If I'm using them in deep cycle or extended use, (My motorcycle and lawnmower battery) then I Use LifePo4 cells, look them up but for now..
I'm not here to be an evangelist for LiPos if you have a problem...
Don't use them, simple.
I have just moved on to the point where I align my solutions based around this tech and will continue to do so.
Cheers
Bill
Last edited by Brycevr; 07-13-2018 at 06:31 AM.
07-13-2018, 06:13 AM
#25
Thread Starter
Join Date: Jul 2018
Posts: 44
Likes: 0
Received 0 Likes
on
0 Posts
BTW ...kids in this hobby.
Don't insult me or the other users of this forum.
If you're a parent then it is your job to learn and pass on the knowledge, not use children to excuse your own ignorance. That's just plain pathetic.
Are you just looking to get a rise or just ignorant.
I'd give a free LiPo upgrade to any person on this forum (tanks) younger than 14YO and registered for more than 6 months.
Tanks are an old persons hobby.
Don't insult me or the other users of this forum.
If you're a parent then it is your job to learn and pass on the knowledge, not use children to excuse your own ignorance. That's just plain pathetic.
Are you just looking to get a rise or just ignorant.
I'd give a free LiPo upgrade to any person on this forum (tanks) younger than 14YO and registered for more than 6 months.
Tanks are an old persons hobby.
Last edited by Brycevr; 07-13-2018 at 06:32 AM.