Contra Rotating Propeller Drive for f3a 2m Pattern Planes
03-12-2016, 10:47 AM
#1577
I just maidened my Agenda with the V4 and Spin 99
Unfortunately it only lasted about a minute, the Spin 99 went up in smoke. I have used Castles with all my 14 pole Hackers without issue, but had a Spin 99 I bought 2 yrs ago for a Pletty that was smoking Castle ESC's So when Brenner said there might be issues with a Castle, I used it instead. I have a Castle HV 120 that I am going to try next. Unless Brenner tells me it will smoke also I will give it a try.
Bill
03-12-2016, 12:40 PM
#1579
03-12-2016, 01:14 PM
#1580
Thread Starter
Hey Bill,
I'm not an expert on motor control electronics, but I'll do my best to give you my understanding of how things work.
An ESC has to switch the voltage from winding to winding so that electric field that's created can keep pulling the magnets in the rotor forward to rotate the rotor shaft.
The speed that this switching occurs is a function of motor rpm, and the number of magnets in the rotor.
For a 4 pole motor spinning at 50000 rpm, this switching has to occur at: 4*50,000/60 = 3,300 Hz
For a 14 pole motor spinning at 32000 rpm, this switching has to occur at: 14*32,000/60 = 7,467 Hz
This means that with the Pyro 600 motor the ESC has to switch the voltage from winding to winding at more than twice the frequency that it needs to with a Neu f3a motor.
What we have found is that the Castle ESC can't switch reliably at this faster speed, which can cause the motor to "lose sync".
What you will probably see is that the ESC runs quite a bit hotter than you're used to seeing, and it can be unreliable in the air. You might even see the motor cut out sometimes.
What we have seen is that the Castle is capable of switching a 10 pole motor like the Pyro 650, but an ESC like the Jeti Mezon is needed to run the 14 pole Pyro 600.
There are other solutions. I know that Dave Lockhart is getting a 10 pole Pyro 600 motor rewound to provide 880 rpm/V kv, which will run with his Castle controller. This will give him a 70g reduction with the motor, and another 60g reduction with the ESC. (Dave is going to use an ESC without a heat sink..) His total weight reduction will be about 260g.
Brenner ...
I'm not an expert on motor control electronics, but I'll do my best to give you my understanding of how things work.
An ESC has to switch the voltage from winding to winding so that electric field that's created can keep pulling the magnets in the rotor forward to rotate the rotor shaft.
The speed that this switching occurs is a function of motor rpm, and the number of magnets in the rotor.
For a 4 pole motor spinning at 50000 rpm, this switching has to occur at: 4*50,000/60 = 3,300 Hz
For a 14 pole motor spinning at 32000 rpm, this switching has to occur at: 14*32,000/60 = 7,467 Hz
This means that with the Pyro 600 motor the ESC has to switch the voltage from winding to winding at more than twice the frequency that it needs to with a Neu f3a motor.
What we have found is that the Castle ESC can't switch reliably at this faster speed, which can cause the motor to "lose sync".
What you will probably see is that the ESC runs quite a bit hotter than you're used to seeing, and it can be unreliable in the air. You might even see the motor cut out sometimes.
What we have seen is that the Castle is capable of switching a 10 pole motor like the Pyro 650, but an ESC like the Jeti Mezon is needed to run the 14 pole Pyro 600.
There are other solutions. I know that Dave Lockhart is getting a 10 pole Pyro 600 motor rewound to provide 880 rpm/V kv, which will run with his Castle controller. This will give him a 70g reduction with the motor, and another 60g reduction with the ESC. (Dave is going to use an ESC without a heat sink..) His total weight reduction will be about 260g.
Brenner ...
03-12-2016, 07:00 PM
#1581
Correct. The current 4.22 Castle software will have problems with the high commutation rate needed for a 14 pole Pyro 600 with the V4 Contra. Max achievable prop RPM will probably be about 3900 RPM, about 27,600 RPM for motor. I ran this combination (14 pole Pyro 600 and Edge 80HV lite) with the PWM at 16khz and 12khz. The ESC will run very hot at 16khz, and hot at 12khz. For the Castle, the amount of amps is not a problem, but the efficiency of ESC running at the high commutation rate is the issue. As FYI, Castle is currently bench testing new software that will greatly improve commutation rate, but an estimate release date has not been set yet. I also ran the same ESC with a 10 pole Pyro 650-83, and had no problems.
03-13-2016, 07:03 AM
#1582
Catching up on this thread and just saw your post.
My Allure at the 2015 NAT was setup with a V3 with Neu 1512-2Y (1380 KV), 10.15 gear, 22x20F and 21.5x20R, and of course Throttle Tech. I round the tips of the props to mimic the shape of the APCs, and trim 1/2" diameter off the rear prop. I think this slightly reduces noise on the sound meter and improves the sound quality in the air...very minor/subtle improvements.
If you check post 1343, my prior testing showed the 22x22F/R is the fastest setup....and not surprising, it is the highest current draw. The 20" props are fast, almost as fast in a straight line. Where the 22x22 props are more noticeably faster (for me) is in maneuvers like climbing loop sections with integrated rolling, or upline snaps.
While not specifically related to 1 particular power system setup, if you keep the plane just a couple meters closer in, you effectively gain quite a bit of pace. I have found it is easier to fly close in with windy conditions with the Contra because the pace of the downlines do not look too rushed close in even when using higher pitched faster setups.
03-13-2016, 02:46 PM
#1583
Thanks for the feedback Dave. I am definately going to try your set up along with Brenners' recommendation as well. I need to see which set up my Agenda prefers especially in the windy Midwest. So far, I have been really excited about the V4. Every time I fly it I become more comfortable with the set up. The new Masters schedule I am between 2700 -2900 mah per flight and I am really shocked and delighted. With my Advance motor and Spark I was routinely pulling over 3800 mah from the batteries. Of course the Agenda is about 175grams lighters and not as draggy.
I am Still extremely happy I chose the V4. Looking forward to competing with it.
I am Still extremely happy I chose the V4. Looking forward to competing with it.
03-13-2016, 11:39 PM
#1584
One additional comment:
The motor timing that I used for all these tests was 24 degrees, and with this timing I was pulling 100A/3500W.
One additional possibility here is that it is more than possible to use motor timing to adjust the maximum amps/power instead of ATVing the throttle back.
I am going to be experimenting with this during this week.
Brenner ...
The motor timing that I used for all these tests was 24 degrees, and with this timing I was pulling 100A/3500W.
One additional possibility here is that it is more than possible to use motor timing to adjust the maximum amps/power instead of ATVing the throttle back.
I am going to be experimenting with this during this week.
Brenner ...
I thought I'd bring ESC settings into the conversation at this point. The Quote above is from last July or Aug,, when Brenner was testing various motors.
I think Brenner said he was using a 120A or 130A ESC - for testing.
Brenner; Have you tested at lower timings than 24 ?
The kV of the Pyro 600 is quite high and a timing set at 24 'effectively' increases the kV further - demanding more Amps from the ESC !
A softer timing would reduce the current demand spikes considerably.
Brian
03-14-2016, 05:10 AM
#1586
Thread Starter
Hi Guys,
I thought I'd bring ESC settings into the conversation at this point. The Quote above is from last July or Aug,, when Brenner was testing various motors.
I think Brenner said he was using a 120A or 130A ESC - for testing.
Brenner; Have you tested at lower timings than 24 ?
The kV of the Pyro 600 is quite high and a timing set at 24 'effectively' increases the kV further - demanding more Amps from the ESC !
A softer timing would reduce the current demand spikes considerably.
Brian
I thought I'd bring ESC settings into the conversation at this point. The Quote above is from last July or Aug,, when Brenner was testing various motors.
I think Brenner said he was using a 120A or 130A ESC - for testing.
Brenner; Have you tested at lower timings than 24 ?
The kV of the Pyro 600 is quite high and a timing set at 24 'effectively' increases the kV further - demanding more Amps from the ESC !
A softer timing would reduce the current demand spikes considerably.
Brian
I tested lower timing, and I didn't notice a big effect. Also, with timing set below 12 degrees or so, the motor was losing sync, and cutting out in the air.
At the time I was using a Mezon 130 Lite ESC, but since then I have been flying with a Mezon 95 Lite ESC. Both work fine. The 130 runs cooler though.
One other thought. I haven't tried this, but the Mezon ESC has the ability to limit maximum motor current to a preset value. Could this be used to limit current spikes?
Brenner ...
03-14-2016, 05:11 AM
#1587
Thread Starter
03-14-2016, 02:41 PM
#1588
Hi Brenner,
I'm not familiar with the Mezon range.
However, assuming it 'does what it says on the can', it would seem like an apt,, use for that function in this application.
Set it at say 90 to 95 Amp or whatever would be the normal top end for a given set up.
Another area to focus on with these very powerful motors is connector and soldering quality. A poor/under-rated connection will fry an ESC in the blink of an eye.
Brian
I'm not familiar with the Mezon range.
However, assuming it 'does what it says on the can', it would seem like an apt,, use for that function in this application.
Set it at say 90 to 95 Amp or whatever would be the normal top end for a given set up.
Another area to focus on with these very powerful motors is connector and soldering quality. A poor/under-rated connection will fry an ESC in the blink of an eye.
Brian
03-14-2016, 03:42 PM
#1589
Thread Starter
Hey Brian,
As soon as we can start flying again I'm going to experiment with the current limiter on my ESC. It might be a good way to dial in the right amount of power based on weather conditions.
Brenner ...
As soon as we can start flying again I'm going to experiment with the current limiter on my ESC. It might be a good way to dial in the right amount of power based on weather conditions.
Brenner ...
03-14-2016, 04:48 PM
#1590
Hi Brenner,
I was thinking more about Bill in the post above and the smoked ESC.
Using it as you are suggesting will likely work but the WOT point will be moving up the throttle range as the pack deplets.
Have you tried the Throttle Tech ?
I plan on having two with different profiles - One for calm and one for high wind combined with prop changes for conditions in between.
At present I use one TT and it is just great in most weather conditions. As I have it set at present the throttle profile is biased towards calm conditions and I can get caught out a little in very strong winds.
I'm hoping that having a 2nd one allowing more power in wind will work. This will need more pack capacity to work through to the end of a flight/schedule.
I don't want a 'hot set up' in calm to average winds or more to the point I don't want the management req'd.
Brian
I was thinking more about Bill in the post above and the smoked ESC.
Using it as you are suggesting will likely work but the WOT point will be moving up the throttle range as the pack deplets.
Have you tried the Throttle Tech ?
I plan on having two with different profiles - One for calm and one for high wind combined with prop changes for conditions in between.
At present I use one TT and it is just great in most weather conditions. As I have it set at present the throttle profile is biased towards calm conditions and I can get caught out a little in very strong winds.
I'm hoping that having a 2nd one allowing more power in wind will work. This will need more pack capacity to work through to the end of a flight/schedule.
I don't want a 'hot set up' in calm to average winds or more to the point I don't want the management req'd.
Brian
03-14-2016, 05:01 PM
#1591
Thread Starter
Hi Brenner,
I was thinking more about Bill in the post above and the smoked ESC.
Using it as you are suggesting will likely work but the WOT point will be moving up the throttle range as the pack deplets.
Have you tried the Throttle Tech ?
I plan on having two with different profiles - One for calm and one for high wind combined with prop changes for conditions in between.
At present I use one TT and it is just great in most weather conditions. As I have it set at present the throttle profile is biased towards calm conditions and I can get caught out a little in very strong winds.
I'm hoping that having a 2nd one allowing more power in wind will work. This will need more pack capacity to work through to the end of a flight/schedule.
I don't want a 'hot set up' in calm to average winds or more to the point I don't want the management req'd.
Brian
I was thinking more about Bill in the post above and the smoked ESC.
Using it as you are suggesting will likely work but the WOT point will be moving up the throttle range as the pack deplets.
Have you tried the Throttle Tech ?
I plan on having two with different profiles - One for calm and one for high wind combined with prop changes for conditions in between.
At present I use one TT and it is just great in most weather conditions. As I have it set at present the throttle profile is biased towards calm conditions and I can get caught out a little in very strong winds.
I'm hoping that having a 2nd one allowing more power in wind will work. This will need more pack capacity to work through to the end of a flight/schedule.
I don't want a 'hot set up' in calm to average winds or more to the point I don't want the management req'd.
Brian
I haven't used a TT device, but I am familiar with them. They are ideal for leveling the load across a flight.
However, I think they are fundamentally different from using a current limiter. A TT device will control the voltage to the motor, but this won't limit maximum current due to a max throttle up line, or from a prop strike.
Ideally a current limit will not be noticed unless there's a need for it due to the aforementioned.
Brenner ...
03-17-2016, 02:08 AM
#1592
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Hey Brian,
I haven't used a TT device, but I am familiar with them. They are ideal for leveling the load across a flight.
However, I think they are fundamentally different from using a current limiter. A TT device will control the voltage to the motor, but this won't limit maximum current due to a max throttle up line, or from a prop strike.
Ideally a current limit will not be noticed unless there's a need for it due to the aforementioned.
Brenner ...
I haven't used a TT device, but I am familiar with them. They are ideal for leveling the load across a flight.
However, I think they are fundamentally different from using a current limiter. A TT device will control the voltage to the motor, but this won't limit maximum current due to a max throttle up line, or from a prop strike.
Ideally a current limit will not be noticed unless there's a need for it due to the aforementioned.
Brenner ...
The amount of compensation applied is maximum at full battery charge and at full throttle. As the voltage diminishes, the corresponding compensation being applied is reduced. It also takes into account the pulse width changes throughout the travel range of the throttle stick, smoothly integrating the correct amount of compensation that is needed at that position, so for a given battery voltage value, the compensation applied is most at full throttle and progressively less at reduced throttle settings.
Best regards,
Last edited by NJRCFLYER2; 03-17-2016 at 02:16 AM.
03-17-2016, 04:57 AM
#1593
Thread Starter
Throttle-Tech does not directly limit current or voltage. It constantly measures motor battery voltage and uses that value in an algorithm that determines how much to adjust the throttle channel signal down to provide the throttle leveling effect. It relieves you of the workload of trying to perform the compensation with the throttle stick for the changes in battery voltage that occur under varying load conditions and as the battery discharges throughout the flight.
The amount of compensation applied is maximum at full battery charge and at full throttle. As the voltage diminishes, the corresponding compensation being applied is reduced. It also takes into account the pulse width changes throughout the travel range of the throttle stick, smoothly integrating the correct amount of compensation that is needed at that position, so for a given battery voltage value, the compensation applied is most at full throttle and progressively less at reduced throttle settings.
Best regards,
The amount of compensation applied is maximum at full battery charge and at full throttle. As the voltage diminishes, the corresponding compensation being applied is reduced. It also takes into account the pulse width changes throughout the travel range of the throttle stick, smoothly integrating the correct amount of compensation that is needed at that position, so for a given battery voltage value, the compensation applied is most at full throttle and progressively less at reduced throttle settings.
Best regards,
Thanks for the explanation. I think devices like these are becoming more and more relevant as battery power density improves, and the power available increases.
Am I correct in saying that a TT device won't limit current spikes, say from a prop strike?
Brenner ...
03-17-2016, 05:50 AM
#1594
Processes inside the ESC and motor are happening at hundreds and thousands of times per second. Peak amps on a watt meter, or ESC log can be misleading as they are not logging / displaying at such a high rate - they are showing an averaged current over a period of time that is much longer than hundreds / thousands of times per second.
A 90 amp setup is 90 amps all the time. When the throttle stick is at 50%, logging or a wattmeter will show 45 amps as an average because 90 amps are not being continuously sent to the motor. The ESC, endpoints, travel adjust, and Throttle Tech can not limit peak amps.....but.....they all can be used to reduce the peak amps that are logged / displayed by ESC logs or wattmeters. Guards for prop strikes and current limiting can not reduce the peak amps that occur; what they do is reduce (or shut off) the amount of power the ESC is sending to the motor, warning the pilot a problematic situation has/is occurring.
PWM frequency and timing, when in an appropriate range, will have very little effect on the peak current. If PWM and timing are substantially wrong for a given setup, commutation errors can occur and that can lead to drastic heat buildup in the motor and ESC (not to mention loss of performance). At the end of the day, the only things that really reduce peak power are smaller props, lower KV, or lower voltage (or possibly a larger motor that is overall more efficient and requires less input power to achieve the same output power).
The V4 with Pyro 600-09 is an awesome combination of power to weight. With any system that can generate so much power, it is very important to have good cooling, proper commutation, and impeccable connectors and solder joints. Anything else is increasing the chances of having a problem.
A 90 amp setup is 90 amps all the time. When the throttle stick is at 50%, logging or a wattmeter will show 45 amps as an average because 90 amps are not being continuously sent to the motor. The ESC, endpoints, travel adjust, and Throttle Tech can not limit peak amps.....but.....they all can be used to reduce the peak amps that are logged / displayed by ESC logs or wattmeters. Guards for prop strikes and current limiting can not reduce the peak amps that occur; what they do is reduce (or shut off) the amount of power the ESC is sending to the motor, warning the pilot a problematic situation has/is occurring.
PWM frequency and timing, when in an appropriate range, will have very little effect on the peak current. If PWM and timing are substantially wrong for a given setup, commutation errors can occur and that can lead to drastic heat buildup in the motor and ESC (not to mention loss of performance). At the end of the day, the only things that really reduce peak power are smaller props, lower KV, or lower voltage (or possibly a larger motor that is overall more efficient and requires less input power to achieve the same output power).
The V4 with Pyro 600-09 is an awesome combination of power to weight. With any system that can generate so much power, it is very important to have good cooling, proper commutation, and impeccable connectors and solder joints. Anything else is increasing the chances of having a problem.
03-17-2016, 05:04 PM
#1595
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Hey Ed,
Thanks for the explanation. I think devices like these are becoming more and more relevant as battery power density improves, and the power available increases.
Am I correct in saying that a TT device won't limit current spikes, say from a prop strike?
Brenner ...
Thanks for the explanation. I think devices like these are becoming more and more relevant as battery power density improves, and the power available increases.
Am I correct in saying that a TT device won't limit current spikes, say from a prop strike?
Brenner ...
That's correct, Throttle-Tech has no current spike detection capability. But now you have me thinking about it...
03-17-2016, 05:10 PM
#1596
Thread Starter
Hey Ed,
Yes, if you could develop a product that combined your TT device with a current spike filter, it would be very useful. (so long as it remained light...)
About two years ago I lost a plane when the rear bearing in a Neu f3a motor locked up, causing my ESC to blow up in mid flight.
By the time I landed the whole plane was engulfed in flames. (it did look kinda cool though, trailing smoke on the way down ...)
Brenner ...
Yes, if you could develop a product that combined your TT device with a current spike filter, it would be very useful. (so long as it remained light...)
About two years ago I lost a plane when the rear bearing in a Neu f3a motor locked up, causing my ESC to blow up in mid flight.
By the time I landed the whole plane was engulfed in flames. (it did look kinda cool though, trailing smoke on the way down ...)
Brenner ...
03-21-2016, 05:49 AM
#1598
Peter
I just maidened my Agenda with the V4 and Spin 99
Unfortunately it only lasted about a minute, the Spin 99 went up in smoke. I have used Castles with all my 14 pole Hackers without issue, but had a Spin 99 I bought 2 yrs ago for a Pletty that was smoking Castle ESC's So when Brenner said there might be issues with a Castle, I used it instead. I have a Castle HV 120 that I am going to try next. Unless Brenner tells me it will smoke also I will give it a try.
Bill
I just maidened my Agenda with the V4 and Spin 99
Unfortunately it only lasted about a minute, the Spin 99 went up in smoke. I have used Castles with all my 14 pole Hackers without issue, but had a Spin 99 I bought 2 yrs ago for a Pletty that was smoking Castle ESC's So when Brenner said there might be issues with a Castle, I used it instead. I have a Castle HV 120 that I am going to try next. Unless Brenner tells me it will smoke also I will give it a try.
Bill
I went with the Mezon 95 and got in 5 solid flights, I checked the current draw on the ground, and was drawing only about 85 amps, Which is consistent with the use of the Throttle Tech. And to add my 2 cents about the power, Lets just say WOW. I am going to have to learn to fly with a lot less throttle.
Brenner
Just a question here to determine if I might have an issue.
Flew it in 45-50 deg F temps and checked the temp of motor and ESC on landing. The ESC was literally stone cold, barely warm, the Motor was showing 155 deg F Based on what you have been saying about the how cool they run, it seems a little hot. It didn't seem to vary even when I was pushing it a little and pulled close to 4000 mah out of my packs, I did notice some grease weeping out between the Front Hub and Rear Spinner. Otherwise no, drag or anything unusual
Thanks
Last edited by Bubblehead575; 03-21-2016 at 05:52 AM.
03-21-2016, 10:24 AM
#1599
Thread Starter
Hey Bill,
I'm glad you are having success with the Mezon.
These motors do run cool, but the 650 runs quite a bit cooler than 600.
155F does seem a little hot for a 55F day. The 650 is very robust to installation, but the 600 is not as robust. You may need to get more airflow over the motor, or consider switching to a 650.
Brenner ...
I'm glad you are having success with the Mezon.
These motors do run cool, but the 650 runs quite a bit cooler than 600.
155F does seem a little hot for a 55F day. The 650 is very robust to installation, but the 600 is not as robust. You may need to get more airflow over the motor, or consider switching to a 650.
Brenner ...
03-21-2016, 02:35 PM
#1600
Hi Brenner,
I believe you may be preparing my V4 which I recently ordered through F3AU. I have ordered the 600 but I am wondering if I should change this to the 650. Our climate here in QLD Aust is quite warm and humid in summer being in the sub-tropics and my current V3 drive operates in an acceptable temperature range but I don't have a lot of head room for our hotter days. My current V3 setup uses to 10.15 gearing with 22x22 R for really windy days and 22x20R for light to moderate winds. I feel that both combinations give the ideal speed range I like for flying. Will the KV of the 650 and the gearing of the V4 provide a similar feel with the same props as I don't want to deal with temperature issues if they exist. I generally fly back to back flights as practise time is limited for me so 6 flights in a row is not uncommon. Thanks again for producing such a great product and your support is excellent.
I believe you may be preparing my V4 which I recently ordered through F3AU. I have ordered the 600 but I am wondering if I should change this to the 650. Our climate here in QLD Aust is quite warm and humid in summer being in the sub-tropics and my current V3 drive operates in an acceptable temperature range but I don't have a lot of head room for our hotter days. My current V3 setup uses to 10.15 gearing with 22x22 R for really windy days and 22x20R for light to moderate winds. I feel that both combinations give the ideal speed range I like for flying. Will the KV of the 650 and the gearing of the V4 provide a similar feel with the same props as I don't want to deal with temperature issues if they exist. I generally fly back to back flights as practise time is limited for me so 6 flights in a row is not uncommon. Thanks again for producing such a great product and your support is excellent.