(09-Apr-2022, 04:40 AM)dwije21 Wrote: Well I gave up on the motors. I think in one of the many crashes I got debris in between the bell and the stator. I ran the motors tab on betaflight and one of the motors started smoking. Surprisingly it actually worked better after that. However, I'm still getting desyncs. I've tried 3 ESCs (speedybee 45 A, skystars blheli_s, and tmotor velox 45 A) with a variety of settings. However, I still can't get rid of the desyncs. I decided to get a set of Xing 2205 2300 kv. The lower KV should make it easier for my ESCs to keep up.

If anyone has successfully used the tmotor 2203.5 2850kv on 6S with a 3" please let me know what ESC you are using. If anyone has any other suggestions please let me know.

Thanks!

I'm planning to use the same T Motors 2203.5 2850 kV with a Jhemcu 45A AIO ESC on a 3 inch frame with some prop guards. But the frame I just bought ( Luma30) is a lot lighter (85g) compared to  IFlight Hornet frame  (158g) and I will use some lighter 1000mah/1100mah 6s so it's not the same load as your setup.

 Hopefully i won't get any desync issue. 

I'm trying this build  after seeing this video by an Aussie fpv pilot recently. 

(09-Apr-2022, 04:55 AM)jasperfpv Wrote: I'm planning to use the same T Motors 2203.5 2850 kV with a Jhemcu 45A AIO ESC on a 3 inch frame with some prop guards. But the frame I just bought ( Luma30) is a lot lighter (85g) compared to  IFlight Hornet frame  (158g) and I will use some lighter 1000mah/1100mah 6s so it's not the same load as your setup.

 Hopefully i won't get any desync issue. 

I'm trying this build  after seeing this video by an Aussie fpv pilot recently. 

Awesome. Let me know how that goes for you. I'm going to try scaling the motor by 80% to see if it is indeed a high kv 6S issue. The motors are great btw as far as thrust and responsiveness. It's just the desyncs I'm struggling with.

Ok I think I figured it out! Lowering rampup power to 15% did the trick! Motor scale is still at 100%!

(08-Apr-2022, 10:45 AM)hugnosed_bat Wrote: pids cause hot motors, heat up to damage. wrong pids makes a quad unflyable everywhere.

freakout on the end of a flip is a desync, it can come from noise about your gopro mount or from the heavy settup. likely you reach the limit of your motorabilities about providing trust.
doesnt seem to important overall, if the settup works on smaller battery, the system will have a more easy task about everything; esc(desync) and pid work. you will get better ability for pid tune. a very heavy settup does need very high pid values in general, very high p and d values, on a smaller battery you will get way better performance by lower values.

let us know how it turns out :-)

So here's a more thorough write up on how I fixed this. I usually lower rampup power to 20-25%. Usually don't go lower than that. However, with this high kv a motor and 6S it required to go lower to reduce the electrical noise that probably confused the ESC from detecting the commutations thus leading to a desync. I started with a rampup at 10%. It flew with no desyncs but was not super responsive and even failsafed at one point which I think was due to just not having enough power to combat the wind. Then I upped it to 15% and it flew way better. I left it there since 20-25% didn't work in the past. At 15% there were no failsafes or desyncs after 3 batteries and I could get to real PID tuning.

I think the trick is to tune rampup power by starting as low as you can go and still arm the quad and then go up from there till you don't notice any more improvement or till it starts desyncing. Then back down to what works. While you could get better results with a really high end ESC it appears this is what you have to do with the majority of ESCs out there.

Therefore, I can also say that the new Speedybee ESC that was sent to me actually works good unlike their previous ones. Also the Tmotor 2203.5 stands a ton of abuse since I've literally crashed this 30+ times in a few days. I even had smoke coming out of the motor at one point due to debris stuck in the motor and it still flies good. The reason I got the 2203.5s instead of a more common cinewhoop size is for the extra power to move this tank. And I have to say if the aerodynamics were better on the frame, I could probably do decent freestyle.

Also the Green Hornet V3 frame that I'm using is aerodynamically crap. However, it is super durable. I haven't broken anything after all these crashes except gopro mounts. It's also very safe to fly around people with the comfort of having foam bumpers.

Finally I ended up using the Gemfan D76 props (5 blades). They are waay quieter than the Gemfan 3052s triblades I was using. Also are pretty smooth in flight. 

Hope this helps someone who uses these motors and is having desync issues. I know I'm not the only one since some of the comments in youtube videos talks about desyncs.

Hope this helps someone!

Quote:If anyone has successfully used the tmotor 2203.5 2850kv on 6S with a 3" please let me know what ESC you are using. If anyone has any other suggestions please let me know.

In general, the further from "typical/normal" you go, the more problems.
3" on 6S is not typical. And HUGE 2203.5 is not typical.

Different ESC, or different FC are NOT going to solve your problem.
And dont bother flashing firmware like 100x.

You are in kinda uncharted territory. There is no magic setting to fix ALL Desync.
You need to slowly methodically go through each BLHeli setting and see which helps YOUR build.

(16-Apr-2022, 08:18 AM)romangpro Wrote: In general, the further from "typical/normal" you go, the more problems.
3" on 6S is not typical. And HUGE 2203.5 is not typical.

Different ESC, or different FC are NOT going to solve your problem.
And dont bother flashing firmware like 100x.

You are in kinda uncharted territory. There is no magic setting to fix ALL Desync.
You need to slowly methodically go through each BLHeli setting and see which helps YOUR build.

Thanks. Yeah as I mentioned in my write up I fixed this by lowering rampup power to 15% and motor timing at 25deg. This worked on my 30x30 speedybee f7 stack. It flies great now and has freestyle response and handling on a cinewhoop frame. Whole reason I built it is to safely fly around people but not feel like a tank doing it. I think I accomplished my goal.

Note: I decided to shave some weight by swapping out 30x30 stack with the tmotor mini stack (20x20). I needed to apply the same ESC settings (15% rampup and 25 deg motor timing) to prevent desyncs.

For what's its worth, i have used 2203.5 2850kv motors with Gemfan 5 blade D76 3" props and 6S (1100mah to 1250mah) without any desyn issue doing roll/flip. The frame is 70-80g lighter. No change to BL- Heli S ESC settings in my case.

Have exactly the same problem on the same motor…but on a Geprc Crown frame with Geprc SPAN F722 HD and esc BLHeli-S DSHOT 600 45A and 3040 props.
Death roll only after full roll with and without gopro…otherwise it flies really well.
Tweaked motor timing, demag and ramp up pwr the same as you did…and re-soldered all motors.
No issues on the bench…
Need to do some more tests in the field with bbox…and in case it doesn’t work I will try with lower dshot, props pitch, bigger capacitor and try to switch motors :-(

(22-May-2022, 09:02 PM)Fma Wrote: Have exactly the same problem on the same motor…but on a Geprc Crown frame with Geprc SPAN F722 HD and esc BLHeli-S DSHOT 600 45A and 3040 props.
Death roll only after full roll with and without gopro…otherwise it flies really well.
Tweaked motor timing, demag and ramp up pwr the same as you did…and re-soldered all motors.
No issues on the bench…
Need to do some more tests in the field with bbox…and in case it doesn’t work I will try with lower dshot, props pitch, bigger capacitor and try to switch motors :-(

That's too bad. 15% rampup with a higher motor timing did it for me. Different ESCs will perform differently though so you may need to lower rampup as needed.

(27-May-2022, 02:11 AM)dwije21 Wrote: That's too bad. 15% rampup with a higher motor timing did it for me. Different ESCs will perform differently though so you may need to lower rampup as needed.

Waiting to test it. At the moment lowered RupP to 25% and Motor Timing to medium high. Have also decreased Motor Limit to limit current…will see. Have ready some bigger capacitor :-)
It’s a heavy build with the Hero10…

(27-May-2022, 05:42 PM)Fma Wrote: Waiting to test it. At the moment lowered RupP to 25% and Motor Timing to medium high. Have also decreased Motor Limit to limit current…will see. Have ready some bigger capacitor :-)
It’s a heavy build with the Hero10…

For me the key settings were motor timing at 26 deg and rampup power at 15%. At 25% it fell out of the sky. Try with the lowest rampup you can do with the motors still spinning when armed (probably 10%). The higher motor timing should give you some extra power. Demag compensation didn't change much for me so I left it at defaults. If you need it it means your quad has already desynced. Just recovers faster at expense of power.

Follow up: apparently solved with RupP to 25%, Motor Timing to medium high, demag to max and by limiting motors to 80%…

(27-May-2022, 10:38 PM)dwije21 Wrote: For me the key settings were motor timing at 26 deg and rampup power at 15%. At 25% it fell out of the sky. Try with the lowest rampup you can do with the motors still spinning when armed (probably 10%). The higher motor timing should give you some extra power. Demag compensation didn't change much for me so I left it at defaults. If you need it it means your quad has already desynced. Just recovers faster at expense of power.

(06-Jun-2022, 06:20 AM)Fma Wrote: Follow up: apparently solved with RupP to 25%, Motor Timing to medium high, demag to max and by limiting motors to 80%…

Great! Glad you figured it out. The motors at 80% probably did the trick. If you want to keep tinkering try 15% rampup and keep motors at 100% and post how you fare. That should give you full rpm range with less electrical noise trading off slight responsiveness (ive never been able to tell personally). Enjoy!

(07-Jun-2022, 02:44 PM)dwije21 Wrote: Great! Glad you figured it out. The motors at 80% probably did the trick. If you want to keep tinkering try 15% rampup and keep motors at 100% and post how you fare. That should give you full rpm range with less electrical noise trading off slight responsiveness (ive never been able to tell personally). Enjoy!

I agree, but for a 6s whoop these motors give a lot of power. Probably more than needed. I'll try to make the changes just for "scientific" purpose  
I've first to deal with another desync issue on a new 5inch build   

Never had so many like in this period 

(09-Apr-2022, 04:40 AM)dwije21 Wrote: Well I gave up on the motors. I think in one of the many crashes I got debris in between the bell and the stator. I ran the motors tab on betaflight and one of the motors started smoking. Surprisingly it actually worked better after that. However, I'm still getting desyncs. I've tried 3 ESCs (speedybee 45 A, skystars blheli_s, and tmotor velox 45 A) with a variety of settings. However, I still can't get rid of the desyncs. I decided to get a set of Xing 2205 2300 kv. The lower KV should make it easier for my ESCs to keep up.

If anyone has successfully used the tmotor 2203.5 2850kv on 6S with a 3" please let me know what ESC you are using. If anyone has any other suggestions please let me know.

Thanks!

Hello, i'm building a new cinewhoop a squirt v2.2 with this same motors, my build is 6s and i choice tmotor f7 hd and tmotor f55 A pro II as ESC.
I continue to have desync problem !!!! Also when i push the throttle idle up the 70 % the drone desync.
Today i try to change settings in bl_heli 32 and nothing happen. When I set the motor timing to 23 deg the drone desync and than the rear right motor start to smoke ;(((