finished my latest build and about to start tuning.
I am using T-Motor Flame ESCs + T-Motor FA24 x 7.9 Props + T-Motor MN701S 135KV motors (all @ 12s).
I read here in another thread that T-Motor ESCs apply thrust linearisation and thus the default MOT_THST_EXPO setting of 0.65 is probably not ideal for this setup.
I have not been able to setup my thrust measuring stand / dynamometer yet and calculate the right value - there’s just not enough time for everything it seems
Has anyone determined EXPO values for T-Motor ESC+Motor+Prop combinations by any chance?
if so, it’s because we graph static thrust, not propellers optimal speed… most of the non-linear response is caused by ESC code/electronics if not compensated.
I just started to work on my good old thrust/current/power/voltage sensing/plotting rig to add RPM , so I’ll soon know if power curve / thrust curve / rpm curve are significantly different, and how much a change of propeller changed it…
Your data is appreciated, thanks for sharing. Expo of 0.18 sounds about right - I’ve heard 0.2 to 0.3 is common for T-Motor and KDE ESC’s.
Oh and just a note: the throttle expo is meant to be measured ONLY for the PWM range used in flight, ie between MOT_SPIN_MIN and MOT_SPIN_MAX. If you include the bottom and top ends that aren’t experienced in flight, the expo will be off. Just wanted to make sure you were aware of this.
On a side note, does anyone know if DJI ESC’s also linearize throttle?
We had a similar setup. We used MOT_THST_EXPO 0 which seems good enough. We did not have a thrust setup so I do not have a curve for Flame 60A. Just assumed it was linear.
Hello my bro ,
I have the same Motor 、Props and ESC with a quad , and
got some problem when auto flying . The props sometimes stop spin . maybe 1second or 2 ,looks dangerous
default setting . expo 0.65 weight 9kg
so I change the expo to 0.18 would be solve the problem?
thanks
0.2 has worked well for me - but it depends on a lot of factors. I use the integrated propulsion series which seems to have different expos than the stand-alone ESCs. Its a mess from T-Motor’s handling of ESC firmware and whatnot, so you kinda just have to test a couple to converge on a solid value.
I run the 605-S arm set on 6s lipo. I tested 0.2 and 0.4. Didn’t notice any difference. I also tested 0.76 (calculated value from wiki) which did not work as well and introduced some over all instability.
I also noticed there’s two different firmware’s for this motor/esc combo using the data link. Have you encountered this?
Yeah the firmware changes all the time based on when you ordered the sets. I have used the MN501S (normal and coaxial) and MN6007 packs and they all seem to work pretty well in that 0.2 to 0.4 range you specified. I always start with 0.2 and if I feel instability then I start tweaking it higher towards 0.4.