Electric Skateboard Braking During Acceleration

[Silverwolf_7]

So I recently completed my first iteration of an electric skateboard however there has been an issue with my speed controller. When accelerating to speed it works fine however if I let the throttle off and begin to coast my motor brakes suddenly when accelerating again while still moving at a decent speed. Any ideas as to why?

[Hackentosher]

You using a hobby ESC? 

[yathis]

You are up my alley.

 

What ESC do you have?

What motors do you have?

[Silverwolf_7]

A hobbyking 120A boat esc. Witha cheapo chinesium 400KV I think.

[Hackentosher]

Just now, Silverwolf_7 said:

A hobbyking 120A boat esc.

It might auto brake when you let go of the throttle. Or maybe your code or whatever that's controlling the ESC is telling it to brake when you let go of the throttle. OR, maybe the firmware on the ESC is designed to stop the propeller (in its intended use case) when you go to zero throttle.

[Silverwolf_7]

It's not coasting thats a problem but accelerating again while still moving. Coasting works like you would expect it to with no auto brake. But if you try to throttle up from 0 while coasting the board stops suddenly.

[straight_stewie]

52 minutes ago, Silverwolf_7 said:

It's not coasting thats a problem but accelerating again while still moving. Coasting works like you would expect it to with no auto brake. But if you try to throttle up from 0 while coasting the board stops suddenly.

Hmmm. I'm wondering if it's because the motor suddenly has power, so is now acting like a dynamic brake. Try a test, get on the board, get up to speed, coast, then floor it and see if it still slows down as bad. Don't hesitate at all, just go to max throttle as fast as you can. The board may lurch, but I have a feeling that it won't stop completely.

[Silverwolf_7]

@straight_stewieI think you're right. I tested it and there was a noticable difference. However standing up while doing that is out of the question. I'd guess the entrance angle is lagging behind the current rotation of the motor causing the brake effect. Maybe a sensored motor and esc can fix it?

[straight_stewie]

2 minutes ago, Silverwolf_7 said:

Maybe a sensored motor and esc can fix it?

It may, but it also may not. Some type of clutch mechanism would definitely help, but I'm not sure of any small ones that could handle that force.