Compass 4926-510 SZ - Flight Report

[Rob43]

Finally, today, I had opportunity to get out and put in a few flights with this new motor installed. Through rigorous research (goin' flyin'), I'd arrived at a 14t pinion on my 700MX-510. It allows me to use the very low headspeed I now enjoy - about 1575 rpm. Since the 4926 is also a 510kV, I put the 14t pinion on the motor.

Sorry for my long post, but I wanted to address a number of things I thought folks might wanna know. I had some concerns:

1. How does the pinion fit on the shaft?
2. Will it clear the frame sides in the first batch frames?
3. Does it have the power which is associated with Compass factory motors?
4. Does it stress the ESC is any way?
5. Does it run cool?
6. Will it overtax my Gens Ace 5300 30C packs?
7. Might it alleviate the recently mentioned tail noise at higher throttle positions?
8. Any other unpleasant surprises?

My findings, thoughts, and less than expert opinions...

1. First off, the pinion is a perfect fit. Revco 1.0M 14t. The flat spot is positioned perfectly nearer the end of the motor just where it's needed. No Dremeling needed.
2. It cleared the frames with a minimal .5mm or so. It's a large motor can. I checked it with a 6" scale as a feeler, and it rubbed, so I didn't know if some in-flight deflection might be an issue. After 4 flights, I saw no evidence of rubbing. I threw a lot at it, and even tried bogging the head with some stupid moves. It looks to be fine.
3. Probably our most pressing question...power? It has abundant power for my style of flying. I flew speeds from 1575 to 2000 rpm. Crazy climbout power, amazing thrust. My favorite power move is to pitch it back tail down like the back side of a tick tock, and apply full pitch to let the dog off the leash. Holy cow does it ever have abundant power! It especially performed better than the 700MX at low headspeed. Clearly, there is much more available torque with bigger can, stonger magnets, and YY stator wind. The stator wire is much larger, single strand wire. I cannot imagine anyone being disappointed!! it also sounds very nice as well. Really smooth.
4. The ESC was quite happy. No temp rise that I could detect. No glitches, no hesitation. Perfect control! (In my case, PowerJive Modes 4, 9.
5. The motor was warm after flights. It was very brisk here today, about 50F. so cooling was aplenty. However, without any real cooling flow in the canopy, I doubt I will see any problems here.
6. I was really pleased with how my Gens Ace took the power. I noted zero temp rise in the packs, just as before. I can't tell that it's working them any harder than my prior setup. I am inclined to believe that the motor is very efficient. Plus, it may simply not being worked as hard to deliver the desired performance I sought.
7. My heli and that of several others have had a noteworthy tail noise at higher headspeeds. Most observe it above 1800 rpm. For whatever reason, wind, magnets, how the ESC manages it, it's gone. In fact, the machine is overall smoother, and sounds MUCH quieter in the air.
8. Certainly no unpleasant surprises. This is the motor which Compass has always wanted for this ship. For those who are considering buying the kit with motor, don't give it a second thought! It's about the perfect match for the beast. Very impressive!

Thanks to all at Compass for the hard work testing and developing this motor. I am very happy to have it in my machine!

[BakedMopar]

Thanks Rob. Can't wait to get mines. Should be here sometime this week.

[heathy]

Yeah, thanks Rob, i'm sold.

[buzzsaw 46]

Great report Rob! Sounds like a fantastic motor. Hope they become available to the masses soon.

[Ah Clem]

Rob,

Great review. I know you have waited for this motor for a very long time, and am very pleased that you have one and are enjoying it.

OUTSTANDING SIR!

[Jason O'Connell]

Awesome Rob!

I hear I will be able to like you again on wednesday

[Cullen Colapietro]

Rob, I hope to see it at the Mid America FF?

[jmackey]

Great write-up Rob. Glad this guy showed up at last.

Can't help but noticing the lack of the 'El Brute' moniker in your review

Hope the power is living up to all of your expectations. Or maybe 'El Brute' was just the code name while it was in R&D.

Are you still running +-13.0 pitch at your low headspeeds? I tried 1650 this weekend and it was fun. Thinking more pitch might be more fun though. I expect that El Brute rocks the low headspeed a lot better than the 700 MX ?

Jay

[G200driver]

Rob,

Can you compare it and the Xera 4530-500??

Thankd

[Rob43]

Originally Posted by Cullen Colapietro

Rob, I hope to see it at the Mid America FF?

I am pre-registered. Right now, I plan to arrive Saturday morning, and spend Saturday night there if i can still get a room. Indeed, El Brute shall be there for sure. My son Nick will be there too as he has all fun fly events!

Originally Posted by jmackey

Great write-up Rob. Glad this guy showed up at last.

Can't help but noticing the lack of the 'El Brute' moniker in your review

Hope the power is living up to all of your expectations. Or maybe 'El Brute' was just the code name while it was in R&D.

Are you still running +-13.0 pitch at your low headspeeds? I tried 1650 this weekend and it was fun. Thinking more pitch might be more fun though. I expect that El Brute rocks the low headspeed a lot better than the 700 MX ?

Jay

Thanks, Jay. I wanted to differentiate this post from the last so as to set aside the my usual BS and provide information as best I could.

It indeed is a Brute, as originally referenced by Klaus Myrseth last summer. With it's abundance of torque, it handles the low headspeed way better. As such, even with the RJX tail (which, although it's nice and smooth, has not yet shown benefit to me - but then, I am no Dave K on the sticks!) I had one sort of loss of tail hold in one of those moves where you enter at high speed, inverted, tail-first, and fly a loop, piro-ing the tail around to nose first as you approach the top, and back around tail first as you pass the crest. With full pitch at low headspeed approaching the top, it blew out for an instant. Luckily I didn't choke, and corrected it. Pretty sobering though! I will need to read up on Vbar bank switching and leave that move until I can try some gain settings for the tail at this ridiculous low speed. Everything else is spot on, and the headspeed is locked in really well on the PowerJive now that the motor has the power to deliver. I could also try some 110's on the tail as well, but then it may have too much gain at the 70% throttle.

[Stolla]

ROB for tail you need to run banks as you want higher gain at low headspeed or it will blow with any tail, especially torque generated by strong motors, you'll probably have to increase precomp as well.
Re the motor can you temp gun it after a hard flight please, would like to know of it has a fan concept that works as well as pyro or mx. Or if it's gonna be "scorpion hot"
Does anyone sell this motor yet?

[buzzsaw 46]

I have not been able to find one for sale yet. I'm sure there is a back log of people that have been waiting for a motor since last summer. Hopefully they will get caught up quickly with those waiting so the rest of us have a chance to buy one soon

[Diviner]

any logs from castle or eagle tree? max amps specifically?

I upgraded to cc160 with all the talk of power, just want to see if I wasted money upgrading for no reason.

Does anybody know the reported specs?

[Dave Ketelhut]

my test motor, which was a pre production motor of what Rob has with only 1.2mm winding peaked 156 amps. i think its fair to compare them and assume you can peak that if not a little more with production motor. this video was with the pre production motor and its no slouch.

https://www.helifreak.com/showthread...338766&page=18

im glad your liking the motor Rob, Sebastian spent a lot of time on this motor and its what we were looking for, unfortunately it took way longer then we thought but i think its worth the wait. the most noticeable quality i found of the motor is how smooth it is like Rob said.

[Diviner]

thanks dave. So if I do my math correctly, the motor pulls around 7000-7500 watts.

[Raynman]

Originally Posted by Dave Ketelhut

the most noticeable quality i found of the motor is how smooth it is like Rob said.

you hit the nail on the head, I couldn't agree with you anymore.

[snaaakeey]

Originally Posted by Dave Ketelhut

my test motor, which was a pre production motor of what Rob has with only 1.2mm winding peaked 156 amps. i think its fair to compare them and assume you can peak that if not a little more with production motor. this video was with the pre production motor and its no slouch.

https://www.helifreak.com/showthread...338766&page=18

im glad your liking the motor Rob, Sebastian spent a lot of time on this motor and its what we were looking for, unfortunately it took way longer then we thought but i think its worth the wait. the most noticeable quality i found of the motor is how smooth it is like Rob said.

Does it have any advantages over the 4525 le ? I am very tempted to get the compass motor as I love the kit motor on the 6hv and I love all things compass.

[dunkonu23]

Rob, I'm happy for you! Man, that motor sounds awesome! I wish I had one. It'll be good to meet everyone at the Mid America Fun fly. I'm gonna be there all week as I'm taking a class. It'll be fun!

I'm especially happy that the noise went away. It's funny how these things work out!

Scott

[Jonnyrl1]

Sounds awesome Rob. I want one now!

[Gawl]

Hmmm, I might be replacing my hk3 4035-560 as that thing always comes down scorpion hot.