feigao 12xl 1390 cogging.help pls

[rat]

hello lads..i have a feigao 12xl 1390kv / mmm esc ,in my hyper st pro.. running 6s-5000mah 20-30c..gearing is 52/17..

when i want to just crawl along little , it coggs...not badly but enough to give me the sh...s. but if i take off a bit quicker it stops..???

after about 5 mins of road speed runs, the motor is at 65-70c..is that getting to hot??

can sombody recomend any settings that i can try.???

apart from that, the thing screems. wheel stands on command....cheers for any advice,,

im a little noob when it comes to the programming side of the mmm esc...

[_paralyzed_]

cogging is inherit to sensorless brushless at low speeds. You can lower a tooth or two on the pinion, raise start power, or give it a good kick before you take off. All should help, but may not completly eliminate low speed cogging. These systems were designed for high speed, and not "crawling along"

[suicideneil]

12Xl on 6s is an unusual setup, especially for a buggy. I would say the cogging you get when crawling is normal- thats a very low kv motor for the esc to try and get spinning from a atandstill or low rpms. I would suggest more like a 1600kv motor for 6s lipo, and just gear it a little differently. Higher start power should help with the current issue, in theory.

[BrianG]

Yeah, the ESC isn't seeing enough rpms at low speeds to get rotor position. If you haven't done so, use firmware rev 1.2 as the starting algorithm is smoother.

[sleebus.jones]

Gotta throw in behind Neil and Brian, Kv is too low. Taking a few teeth off the pinion might help, but it's still going to be difficult to get proper commutation. The only real way to fix it is to go to 7S, but that's out of spec for the MMM.

[rat]

cheers guys..great info..appreciated(-------o.o-------)this much..

sorry neil, its a truggy...i thought it was gearing and the kv..its the only motor i have so it will have to do.. cheers lads..

[BL_RV0]

Raise start power and timing.

[rat]

cheers lads..start power to medium and its better..