[sveness]

Hi All

I have been struggling for weeks to tune my new FPV racer.....

RCTimer 250 Bee-rotor frame
Emax 2204 2300KV Motors
12A SimonK Esc's
Gemfam 5030 Props
3S 1600mAH Battery
CC3D
Lastest LibrePilot Firmware
No HD Camera, just FPV cam.

I have in the past used optune with my other quads and it seems to work fine, but not with this one. So decided to try manually tune the PID's.

Seems I can't get a sweetspot, Integral seems to be the main issue. Either its too high and the quad wobbles, or too low and I can't get it to keep an angle. Just how sensitive are the PID values? Will an increase of .0001 make a huge difference?

Second issue I have is yaw. As soon as I apply any yaw, the quad loses attitude and rolls to left or right depending on yaw direction. I then need to correct roll to get it back to horizontal. This effect is quite severe and makes cornering difficult.

Also the quad seems to be under powered. With no throttle curve I need about 60% throttle to hover. I also find it difficult to maintain height and difficult to punch out when in trouble. Can the lack of power prevent the quad from achieving a proper tune?

Thanks and look forward to some suggestions. Man this PID tuning is an art!!

Shane

[f5soh]

Hi,

The underpowered thing is strange and do not help for tuning.
Maybe redo Esc calibration.

Can you share your UAV file ?
File > Export  UAV settings.

Laurent

[sveness]

Attached uav file.

[sveness]

Thanks

I have re-run the config wizard and therefore re-calibrated the esc's multiply times to try and get it right, has made no difference with the power.

It does seem strange as the quad is not heavy and there should be more than enough power considering the specs?

[f5soh]

Looks like you imported a old config file, still some values that are from old versions.

Vehicle tab > Reset the Throttle curve (0 -> 100%)

Can you check if every motor react/sounds the same, if one fails it can cause weird results.

Output tab > Test Outputs

[sveness]

Yes, imported UAV from Openpilot CGS but was sure i redid the wizard, maybe not.

Yes all motors seem to be fine from the output..all spinning at exactly 1116. Haven't tried to push them to max throttle though?

The ESC are mystery 12A, Chinese cheapies I think. Have ordered some kiss 4S esc's and a 4S lipo, hoping that will sort, but they on the slow boat from China

Still would like to figure out why though.

Do my PIDs look OK? I have little experience with PIDs and not sure what ranges are acceptable?

[sveness]

I would say the biggest issue is the roll on yaw, does anyone know if this is related to PIDs?

[f5soh]

Nothing bad from PID, you can also use the Easytune / TxPID that do the calc for all "ID" from one "P" term, also the auto-Yaw

You can maybe reduce the Attitude numbers from 25/28 to 20, higher value can add some noise.

About the Roll / yaw issue i'm pretty sure is related to the "underpowerded" issue.
How the quad is balanced ? Equal distance between front and rear motors ?

[sveness]

Quad pretty symmetrical and balanced.

I have a feeling the ESC's are a problem.

I think I'm gonna give up for a bit and mothball it until the 4S stuff arrives. Will go back to my older Tarot for now, which flies like a dream.

Thanks

[f5soh]

The issues you describe can be caused from only one motor  that differs from others.

Go full Throttle with one motor that give only 70% power and all others motors give 70% to maintain level in attitude.

Better wait new Esc.