Board logo

Anyone built a twin motor toylander?
Mr Whippy - 9/1/13 at 11:37 PM

Yeah about to start one myself, just got all the wood but got a question about the twin motor control

If you've tried it did you have to lift the throttle while cornering as the manual doesn't make much sense since it seems to say the speed controller gets confused if powered round a corner but also says you get a differential effect with motors connected in series...like make you mind up?!

did ask on the toylander forum and got no reply's

I know some on here have done them in the past so thought I'd ask here too

Any ideas? thanks

ashg - 10/1/13 at 12:09 AM

Adrian Reeve built one for his kids.

Mr Whippy - 10/1/13 at 12:12 AM

quote:
Originally posted by ashg
Adrian Reeve built one for his kids.


thanks, I'll send him a U2U

bi22le - 10/1/13 at 08:52 AM

I design wheelchairs for a living and knowing that they have casters but toylanders have functional front wheels the difference would be minimal.
I could imagine that unless the grip levels change the torque from the drive motors would push through the fronts and it would go straight on.

Would love to see a build log if you have time to do one.

MikeRJ - 10/1/13 at 12:18 PM

Two DC motors in series will act very much like an open diff; slow one down and the other will speed up. However, if the speed controller is doing anything tricky like measuring motor speed by commutation current changes, then two motors in series is quite likely to cause problems. A simple open loop PWM controller should be fine though.

Mr Whippy - 10/1/13 at 12:45 PM

Thanks for the replys

Am I right in thinking then I should be looking at an open loop controller rather than one that is trying to maintain a set speed, maybe that's why the controller would get confused if two motors are turning at different speeds?

I have been looking around see some 24v 500w PWM controllers for just £28, might give them a look at as the toylander one is vasty more expensive

cheers

rf900rush - 10/1/13 at 12:49 PM

I would agree with MikeRJ

Speed controllers without EMF feedback should be ok.

Worst case loading would be both motors stalled. Starting on a corner will have one motor loaded less, the other more.

Current building a Toylander 2 , and one the finishing stage.
But I am using a 24 V mobility scooter motor.

Will very likely build my own speed controller.

coyoteboy - 10/1/13 at 01:01 PM

Two motors in series with a constant speed controller would be a very poor design. TBH two motors in series is a bit weird too but it'll work if it's voltage controlled, rather than speed or current controlled.