MIXMASTER

My Feedback: (15)

It looks to me like it will work, I'm just not sure what the "assembled" and "kit" versions are. Assembled is only $10 more($27), if that means all the wires/connectors are pre-installed and all you have to do is jumper the pins as needed(ganging 2 or 3 servos), thats fine, if you've ever done any soldering, thats no biggy. I think you could still use a Battshare/2 Batts with this board. So you would have 2 batts, 2 switches for redundancy. I went to Hitec & Futaba web sites for current ratings on digital servos, the general consensus is 1.6- 2A under heavy load. Futaba claims 1.6A for high torque servos(they only go up tp about 200oz.) Hitec claims 2A, but for "standard digital", that could mean the lower torque servos(100 oz. & less). I sent both an e-mail for clarification & specific product ratings, hope they answer me. I went to a year of Technical school for basic electronics, then worked for a computer company over 25 years, have tested,repaired,upgraded many different generations of circuit boards yet this issue is still escaping me, there's a lot to consider in the "circuit", from the batts, connectors, gadgets,to the receiver,wires/connectors again & then to the servos. Its hard to get specific technical info like: what is 22g wire Amp rating, what does a 5955TG draw under heavy load, what is the current rating for the receiver buss??? These are all I need to know but get many different answers here, so hopefully the mfg's can help me here. By the way, does Smartfly provide you with its wiring amp rating, connector amp rating, max constant current rating?

MIXMASTER

My Feedback: (15)

Are you talking about 26guage standard wires? If so, then the 22g HD wires would have a lot more current capacity than 3-4Amps?
From my experience, connectors that are operating warm/hot over time can oxidize, resistance builds up and then more heat and eventually connectivity fails(even burns up). I wouldnt want any connectors/wires in my plane getting warm, not good in the long run.

MIXMASTER

My Feedback: (15)

Its starting to come together now, Futaba has e-mailed me back with the specs. on the 607FASST rcv=8Amps constant, 10A surge. Now I know I have to do something with this configuration Radio/rcv. for my 33%, it will have 8 5955TG's or like servos. From what I hear, JR 8711 really suck the juice more.(4 Amps??) So it looks like at minimum, I'll have to get the Servocity power board, SF P.E. or maybe even look at upgrading my radio/rcv.

Rcpilot

My Feedback: (78)

Plane: World Models Extra 300L 90" wingspan
http://www.airborne-models.com/html/...p?ProductID=76
http://ecsvr.com/abm/shopexd.asp?id=1318

Engine: Stihl 75cc converted by Ralph

Servos: 1x JR8411 per elevator half. 1x JR 8411 per aileron. 2x JR8411 on the rudder in an SWB tray.

RX's: 2x AR7000 Spektrum

Batteries: 2X 2100mah 6V MH high discharge (20amps continuous) 14ga wires and Deans connectors.

Regulators: 2x Smart-Fly (5amps continuous ... 9amps surge) Deans connectors in

Switches: 2x Smart-Fly SuperSwitchHD with Deans in and out.

Each battery has heavy duty 14ga leads out with Deans connectors. Those plug into the SmartFly HD switches. The switches have Deans on the output and that plugs into the regulator. So far, so good. No loss of power IMO.

Regulators can do 5 amps continuous. Each regulator has 3 heavy duty 20ga servo leads and servo connectors going out. Those 3 leads are plugged into the RX on that side of the plane.

Each RX has 3 heavy duty servo leads coming from the regulator into the RX. I should (in theory) be able to push 9..12 amps of power through those 3 leads. So, I can push as much power through the leads as the regulator can put out.

Left side RX:
1 - throttle
2 - L. aileron
3 - power lead from regulator
4 - rudder servo #1
5 - power lead from regulator
6 - power lead from regulator
7 - empty

Right side RX:
1 - empty
2 - power lead from regulator
3 - JR Matchbox out to both elevator servos. Matchbox is powered from one lead off the regulator.
4 - power lead from regulator
5 - choke
6 - R. Aileron
7 - rudder servo #2

It works flawlessly. Some people would say I don't need dual RX's on a 30% plane. So? I don't care. I wanted to put enough power into the RX to make sure every servo had all the power it could use. That took up 5 RX ports and one port on the Matchbox. The ONLY other way to supply that much current is with a power expander.

In theory, I can run 10amps continuous through this system. The ONLY limitation is the regulators. Each can only put out 5 amps continuous. Even the wildest full throttle snap or blender wouldn't put a 9amp draw (surge capacity) on either regulator. The plane just isn't heavy enough and it's not fast enough and it doesn't have the control surfaces to exert that kind of loads on the power system. And........ I know better than to do a full throttle blender or a full throttle wall. The airplane is so grossly overpowered, it would explode the airframe before I maxxed the power system.

The reason the rudders are mixed with the radio is because they both move the same direction. They are in a tray and ganged with ball links and 4-40 rods. If one had to be reversed, I would have used a Matchbox. Since they both travel in the same direction, they can be mixed on channel 4 and 7. The endpoints and sub-trims of each servo can be adjusted to make them work from 0 to max throw in both directions and on low or high rates without any binding or excess current draw.

The elevator servos are run through a Matchbox because the DX-7 won't mix them correctly so they both travel EXACTLY together and have the same endpoints AND still match at low rates or high rates. It's beyond the programming capability of this particular radio. You can mix them, but it won't be NEAR as precise as a Matchbox. If you understand, good. If you don't .. all I can do is dare you to try it and show me a video of it working perfectly on low rates, high rates and perfectly synched travel from 0 too max throw. I'll save you the trouble, it won't work.

Power expander not necessary. [8D]

cap10b

Virginian,
You can see you did open a can o worms. My own personal opinion I fly and use the power expander for anything 50 cc and above. I also fly without
a power expander 50cc and above. So it just depends on what you like to do. For me a power expander makes it easier to power the servos with
one voltage and not run that same voltage thru the receiver. AKA I can run straight 7.4 VDC to the power expander with no regulator and not
go over 4.9 to 5.0 VDC to the receiver. This means the servos get all the power they want no matter how far away they are and you don’t over
volt the receiver. The power expander take power spikes and evens them out and still isolate the receiver away from the spike. The EQ 10 lets
me incorporate Smart Fly equalizers into the system so I don’t have to hunt for a place to Velcro them.

If you run A123 and like them you really don’t need a power expander unless you just want to run one. Sometimes a Power Expander makes
the radio install a little cleaner and easier to change receivers or a servo. I've run A123 with no power expander and got good results and I've run Li-On
and Smart Fly dual regulator and had good results. 72Mghz or 2.4 it made no difference. I did some tinkering once with some old digital and analog radios that I have
and they were notorious for acting jittery and glitchy stand alone. Ran a power expander on one that was glitchy and it calmed that radio down. So much
so that I can trust it to fly it again. Had a plane once powered by a BME102 with an old bark at the moon C&H ignition and could not fly it stand alone with
a good radio. Installed a power expander and some torrid coils and it calmed that barking ignition down enough that we could fly no problems.

How about this, you might be better off buying a new radio on 2.4 than investing in power management equipment if you think you don’t need it.


After all I only ask why not

jds

thevirginian

Here is what I ended up with for my 35% WH Sukhoi:
Two MPI Miracle switches with adjustable regulators and fail safe feature, two Spectrum receivers, and two 3600 MA Lipos with Deans connectors. NO POWER EXPANDER . I think I am safe, very safe with that set up. Total set up was $310.00 including the two Spectrum receivers.

icando3d2

My Feedback: (15)

the expander in terms is like your tires on your vehicle getting your planes to and from a field. worn out tire will hold air and well who knows when it will blow and most certanly when it does you will be like dern i should have fixed it when i saw it. the expander will definatly give your peace of mind mine has and my friends has now tonight just for kicks i took my 60 cc size plane i have high torque servos all around and set up my dmm"digital multi meter" on amps just to see what would happen. well in the event of everything lock to lock with no load on servos i was able to produce 8 amps spike but with load on what i could load with some assistance from some buddies we were able to see the load increase to as much as 11 amps spike and yes all is kosher on servos look at specs online. look at this for servo leads TBM conducted its own servo extension testing using the equipment shown above. We found that adding a single servo extension (22 gauge with universal connectors) between the Rx and the servo will cost you 1.5% - 5% of your power to that one servo. Adding another extension will cost you another 1.5% - 5% and so on. In one of the many tests run, I put ten 6"extensions in series and measured a total drop of 15% of the maximum torque that a single JR-8711 could put out. In another test, I put ten 48" extensions in series (40' of extensions) and found the drop in power to be 55%. Therefore losses due to servo extensions is a combination of plug losses and wire resistance losses.
POWER LOSSES IN SERVO EXTENSIONS this plane doesnt have a box in it and let me tell you i fly the crap out of it and run regulators on 2 lipos but i know when to lighten up on the servos because its almost as if you can feel the sticks get soft because of the load on the electronics. Now what i like you maynot kinda like beuaty is in the eye of the beholder so im not trying to convence you to run out and buy one Just my .02 cents.
thanks
Chris

RTK

My Feedback: (1)

A power expander does definitely give some people piece of mind, but not necessary in a 35%'er if set up correctly. I have and do run both with equal reliability and performance.

icando3d2

My Feedback: (15)

i completely understand im building a 35% cap 232 right now have it ready to cover and as much time as i have put into it and have not spared time in the build i wouldnt spare that expense right now. and most people wouldnt I have ran these large planes both ways. I do have a great thing to tell you about with a recent smart fly. my buddy put his yak into a tree top last weekend. the smart fly stayed in the tree top so down came the tree it was my job to watch the unit and try to recover it with minimun damage when i rescued it i had wires smokin it has dual batteries lipos, the leads on main power out had shorted and the unit had regulated power and shut that battery off it saved the battery and avioided a nasty fire i was amazed. any how great thread and good job my fellow Virginian at opening up a can of worms LOL just kiddin.

Hammbone

My Feedback: (309)

Standard plugs and wiring have limits on the amount of current they can pass.
Will a plane fly with limited current flow? Yes, it will, and you may not even know that you have limited current flow. Your control surfaces will still move, they just will not have the power or the authority that they could have if you had a better set up.

In my opinion, if you have a 1/3rd scale plane or larger, and you are not using a Power Expander, or a 12 channel JR Powersafe rx, or something similar, you are limiting your current flow.
My goal is to provide 3 amps to each of my servos. This may be a little overkill, but I'd rather have too much than too little.
You will either have a system that provides more current flow than you need, or you will have a system that provides less current flow than you need. Decide which one you want.

A standard plug is rated at 3 amps.
In order to reach my goal of supplying 3 amps to each servo, I can never use a standard plug inline from my power source going to more than one servo. I will never use a "Y" because this means I would have a single standard plug inline going to more than one servo. If I did this, I would cut my power supply in half. Instead of having 3 amps going to one servo, I would then have 3 amps going to two servos. This would only be 1.5 amps per servo. I have not met my goal, and I have just limited my current flow.

The only way I can provide 3 amps to each servo is by using a Power Expander, or a JR 12 channel Powersafe rx, or something similar. This is because I need a place to plug each individual servo into the power source. Each individual servo needs its own power supply. The Power Expander or 12 channel rx provide enough ports to plug in each individual servo into its own power supply.

The standard plugs just are not capable of supplying enough power for more than one servo.

The new, more powerful servos that are available to us now use more and more current. If you are not supplying them with enough current flow, you are not going to get the available torque from the servo. It will still work, but you may only get 150 oz in of torque with a poor set up, when you could be getting 300 oz in of torque from that same servo if you had a good set up.

There are more things to consider as well. If you have 10 servos plugged into a power source, and you have a goal of providing 3 amps per servo, your power source needs to be capable of providing 30 amps (3amps per servo X 10). Is your battery capable of providing 30 amps, or are you limiting your current flow? Many batteries can not provide 30 amps. Now, do you have a regulator inline somewhere? Is it capable of passing 30 amps, or is it limiting your current flow? Do you have an inline switch somewhere? Is it capable of passing 30 amps, or is it limiting your current flow? Is the wiring you are using capable of passing 30 amps, or are you limiting your current flow?
There are many ways you could be limiting your current flow. You have to evaluate your system requirements and make sure each individual component you are going to use is up to the task.

The choice is yours..................

Jim

DadsToysBG

My Feedback: (35)

On my GP Extra 330 38% I have 6 JR 8611 2 8711 on the rudder, throttle and smoke. I'm using a Futaba 12fg with 2 A123 2300ma receiver packs. ! a123 on the gas engine and 1 a123 on the smoke. I have 10 of the 12 channels plugged in using the number 11 for the second receiver battery. Also duel switches for the receiver. Dennis

Rcpilot

My Feedback: (78)

But you're only using 2 plugs to power all that. At best you're getting 6-8 amps into the RX. I'm not saying it doesn't work. Obviously it does because you're flying the plane.

Thats why I ended up using dual RX's on a 30% plane. I wanted to put up to 9amps into each RX, so I plugged 3 leads into each one. My regs can only deliver 5amps continuous so with 1 per RX I can get 10 amps continuous to the 2 RX's, but I can deliver up to 18amps on a spike with the dual regs and 3 leads to each RX.

Flyfalcons

I like the people who overthink their radio systems. They make for good entertainment. [8D]

thevirginian

[sm=thumbs_up.gif]
Here is another thought: We flew 30, 35, 40% without trouble long before someone started to market the Power Expander and similar gadgets.

Flyfalcons

Silence!!!!! I need entertainment!

flatspinjim

My Feedback: (3)

Everyone now knows that you can't fly anything over a 50%er without a power expander now that they have come out with them![:@]

MIXMASTER

My Feedback: (15)

I got a reply from Mike Mayberry of Hitec , he stated that 2 amps working, 4.2 amps on a stalled 5955TG or 7955TG. I think the 2 amps was a worse case load(very large surface) . My guess is I'm not pushing 2 amps thru my 5-5955TG's in my 30% Yak. If they were, my receiver(Futaba 607FASST) would be smoked by now since it only has 8 Amp. continuous rating,10 Amp burst. Its a TOC-E Yak with large 3-D surfaces, one receiver and one servo/surface. I use a single 2700mah Nimh battery and have gotten up to 4 flights on a charge, so again I doubt my 5955's(5) are pulling 2 amps.

Steve

My Feedback: (54)

Hammbone makes a lot of sense on the setups. I checked my Li-Ions and they are rated at 4 amps max. I use dual packs and dual switches, but with standard connectors. My switches are the Futaba HD switches that come with the 12 and 14. My regs are Fromeco and are capable of 9amps per reg, but again with standard connectors. I've never had any issues with my planes running this setup, but then, I'm also probably not letting the servos utilize there maximum potential. I can go to the Li-Pos and gain the C rating. I'd also have to use the larger wire and connectors on the power supplies, but I'll still have a standard connector going into the reciever, or the power box. All servos and switches I use come with a standard connector and would need to be changed to overcome the bottle neck. Thanks for the info Hammbone.

Hammbone

My Feedback: (309)

You're welcome. I am only trying to help.
I do realize that my set up is overkill, but that's is exactly what I want. I know that my servos will always get the current flow they need. I don't have to wonder if my set up is inadequate, or barely adequate.

For all the naysayers that are saying the "old" set ups work just fine, I have a couple of questions for you:

1. If the "old" set ups work just fine, why did so many people have problems with the Spektum brown outs due to limited current flow, when first switching over to 2.4Ghz if the "old" way of doing things works just fine?

2. If you guys are refusing to use new, improved current flow technology, do you also refuse to use new, improved servo technology? Are you naysayers still using "old" analog servos with 100 in ozs of torque? After all, we all know that planes used to fly around fine with those servos. Why should you switch to a new, improved servo with more torque when the "old" ones worked just fine?

Set up yours planes however you choose to. The choice is yours................

Jim

flatspinjim

My Feedback: (3)

Hammbone, I do agree that sometimes newer is better. I just set up a new 35%er and I switched to A123 batts, but I do like to keep things simple. I think the electrics in our planes are the weakest link and the most prone to fail that's why I try to avoid regulators and such. I do like to tinker with setups and I can tell you do too, which is great for the hobby! And I'm sure everyone on here appreciates your info!

Hammbone

My Feedback: (309)

Hey flatspinjim,
I'm all for simple too.
It doesn't get much simpler than two A123 batteries plugged directly into a Power Expander, with one failsafe Power Expander switch. Then just plug your servos (and rx) into the Power Expander.

Or you can use a JR Powersafe rx and plug the A123's directly into it with one failsafe Powersafe rx switch. Then just plug the servos into the Powersafe rx.

It just doesn't get much simpler.

Jim

Flyfalcons

Yes it does, two A123s into a receiver.

flatspinjim

My Feedback: (3)

On my setup I just ran 2 A123's through Smartfly switches which have 2 leads going to the reciever. Gave me 4 leads going into the reciever. That should give me anywhere from 12 to 20 amps into the reciever if I need it considering the connecters will handle 3 to 5 amps.
I have a feeling niether of us will lose a plane with either setup.

icando3d2

My Feedback: (15)

instead of guessing how many amps your pulling, invest in a DVOM and check it it has given me a sense of security.

Hammbone

My Feedback: (309)

Knowing your current flow is good, but a device that measures current flow does only that.
If you have a poor set up with limited current flow, the device can tell you what your current flow is, it can NOT tell you what your current flow might be if you had a better set up.

I've seen several guys come on the forums and say that they only have "X" amount of current flow as measured in flight by an inflight data recording device. Well, if they have a poor set up with limited current flow, then yes, they are going to get low current flow readings, aren't they?

The highest current flow data I've seen posted on the forums is 22 amps on a 35%er, and 42 amps on a 40%er.

Now if some of you guys think the "old" way of doing things is capable of handling this much current flow, go right ahead and continue to do it the "old" way.

Jim