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StartUp in OpenLoop with Duty Control really jerky

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StartUp in OpenLoop with Duty Control really jerky

Dear VESC Team, Dear Usual Suspects,

We are still testing our two motor setup and try different configurations (28 mag polepair) Hemotec 120.05 kv 135; 150A cont; 180A peak. 

We control it via UAVCAN. 

If we use "duty cycle" as control mode, the ramp up is really jerky, the motor tries, but needs multiple attemps to go up and running....(start, stop, start, stop...)

We tried all pre-sets (Propeller, General, Heavy....) not a big change. Increasing the OpenLoop RPM to 2800 is quite good, at least when the motor is warm, but not good when the motor is cold.

Any suggestions?

Kind regards,


P.S: Current is smooth, RPM is okay. 



Last seen: 1 week 1 day ago
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Joined: 2016-12-27 20:19
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If you see a difference in cold to warm behavior, you can adjust the resistance value a bit (+-5%). You should maybe use a temp probe and activate temperture compensation and set the base temperature correctly. Some of these high pole count motors also need some tweaking. Watch Benjamin Vedders Youtube channel to see how it is done.

You can also try to use HFI or silent HFI. The HFI voltage might need some tuning via the START, RUN and MAX Voltage setting.