Motor Breaking HELP

[samlan16]

My car broke today. I'm screwed.... It originally traveled straight for up to 12 meters with only 10 cm of curvature, but now it f***ing curves 30 cm at just the 5 meters mark. Do i just kill me myself? I think i should

Um, no. We all deal with technical issues on our builds.

Try aligning your wheels again. If that fails, consider using a microprocessor to cut power to your motor instead of physical brakes.

[Bazinga+]

Yeah one axle drive axle with gear ox and motor, while the other axle has the wingnut breaking and microswitch.



My car broke today. I'm screwed.... It originally traveled straight for up to 12 meters with only 10 cm of curvature, but now it f***ing curves 30 cm at just the 5 meters mark. Do i just kill me myself? I think i should

If time is an issue then you just need to find a quick way of realigning/adjusting one of your axles. If that's not possible then check if it curves consistently. If its curving consistently then just calibrate it with a curve and change the angle at which you launch it every time Not great but it'll work.

[iwonder]

The way it sounds you're only using 1 of 2 axles to brake right now, anything you can do to brake with both axles will help dramatically.

Would it? In theory it shouldn't.

How wouldn't it?

[Bazinga+]

The way it sounds you're only using 1 of 2 axles to brake right now, anything you can do to brake with both axles will help dramatically.

Would it? In theory it shouldn't.

How wouldn't it?

It wouldn't help with his problem because you don't want both axles to completely stop moving because then the car will still skid to a stop. You want the axles to constantly deccellerate to a stop and be able to avoid error in skidding.

[windu34]

Braking with both axles should help because there will be more contact with the floor thus the coefficient of friction should be increased

[Bazinga+]

Braking with both axles should help because there will be more contact with the floor thus the coefficient of friction should be increased

No thats not why. The coefficient of friction depends only on the material, not contact area. But friction force is friction coefficient times normal force so yes breaking with both axles should double your force from traction. The problem is you need to gradually slow down and not just slam a wingnut in and skid to a stop, which is difficult to implement on both axles.

[iwonder]

Braking with both axles should help because there will be more contact with the floor thus the coefficient of friction should be increased

No thats not why. The coefficient of friction depends only on the material, not contact area. But friction force is friction coefficient times normal force so yes breaking with both axles should double your force from traction. The problem is you need to gradually slow down and not just slam a wingnut in and skid to a stop, which is difficult to implement on both axles.

But in a thread discussing motor breaking, that suddenly becomes incredibly simple to implement.

[cantthinkofausername]

OK, before anyone posts another word, this typo is hurting me. Braking is not breaking. We DO want our EV's to brake on any mm mark given. We DO NOT want to break our motors.

[Bazinga+]

Braking with both axles should help because there will be more contact with the floor thus the coefficient of friction should be increased

No thats not why. The coefficient of friction depends only on the material, not contact area. But friction force is friction coefficient times normal force so yes breaking with both axles should double your force from traction. The problem is you need to gradually slow down and not just slam a wingnut in and skid to a stop, which is difficult to implement on both axles.

But in a thread discussing motor breaking, that suddenly becomes incredibly simple to implement.

You would need 2 motors and 2 wingnuts for thatm one on each axle, which isn't desirable because your error is doubled.

[iwonder]

Alright, fine.

One axle has a wingnut brake, the other has a motor, that's what we're talking about, right? There's already some sort of switch to turn off the motor. Using that switch, remove the battery and put say a 3-5 ohm resistor across it instead. The motor wouldn't 'slam on' the brakes, because of the resistor, but it would help.