Having trouble setting up vx3 remote with fsesc75300 - skipping to 100% throttle

I’m trying to set up my 65161 motor with the 75300 vesc but the throttle is dead from 0-10% then jumps straight too 100%

Ive swapped to ppm control and it now works normal after 10% (still dead before) just unsurely if its bad to use it this way as motor is randomly pulling over 100 amps on startup (11%)

If it still gives erratic throttle then it’ll be risky to ride. A sudden full throttle, you go off the board in a surprising way, more risk to hit foil or propeller

@DisappointmentFPV

I am just in the process of getting the same Flipsky motor working with a Flipsky 75200 and recall while configuring the VX3 that there is a setting for throttle sensitivity.

Perhaps altering that value would help.

BTW Flipsky cautions against running their 65161 out of the water much

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Are you running it out of the water when this happens?

ive tired in and out of the water with a prop and its the same either way

@DisappointmentFPV

I’ve been having quite a time configuring my Flipsky 75200, VX3 and 65161 motor.

I was having erratic setup issues with the motor either not spinning or making ugly noises or doing exactly what you describe either nothing or everything.

My problem was a bad solder job I made when I put the motor connectors on the VESC. I fixed that and ran setup in PPM only and the motor spun smoothly albeit with the same weird throttle response nothing or all. Flipsky has published a blog about setup that was very useful.

I want to run my setup in UART mode with the Flipsky Bluetooth 2.4 v4 module and a waterproof Android tablet anyway so didn’t waste much time in PPM mode.

The VX3 displays considerably more info in UART mode (Shows RU instead of RP on its display) and the tablet will let me make changes if required while down at the waters edge.

I find the throttle “response” to be somewhat smoother in UART mode but it still spins motor at a fast - max RPM way below 100% throttle on the trigger.

Some research leads me to believe that my quirky throttle is because everything I’ve done so far has been on a workbench and no prop. There is little to no resistance to shaft rotation so the VESC isn’t able to perform properly.
I have read that even water tank testing although better than dry doesn’t yield true results. The only sure way to determine if you need to “tune” is when your on your board

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Vesc can deliver several control methods but most give current control throttle - and with no load a current of 2-3A is enough to go full rpm so almost all of your throttle range is useless. Once the motor has some resistance the current throttle control will work better.

from memory there’s duty cycle as one of the control methods selectable in the vesc, this will give a speed control of the motor that could work better at low load.

But: FOC control method is normally more efficient than the other methods so when that works it should be used.

(That static thrust test is not the same as speed runs with a propeller is not related to this.)

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@Larsb

Thanks for the explanation. I’m new to all of this so just went with my layman’s version of what you have explained😀

The Flipsky blog reference configures the setup to be FOC with PPM port Current control on the 75200. I’ve gone a step past that by switching to the UART ports pairing via the Bluetooth module but have not changed any values as of yet.

Flipsky warns against using the 65161 motor out of the water much to protect the integrity of the ceramic seal of the motor so won’t be doing anymore bench testing.

I am waiting for some warmer weather so I can rig a tank test outside to get some feel for how things work with the motor with prop submerged. I don’t think I will attempt much “tuning” until I can get out on the water. Right now not possible as the lake where I will be using it is still frozen😀

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