Re: Speed controllers [TANKS]

[Frank Pittelli <frank-at-rctankcombat.com>]

Dan W wrote:
> Just a thought.
> The speed controller designed to be used on the electric scooter, which 
> uses one 250 watt motor for propulsion and costs less than 15 bucks, 
> work as a speed controller for the tanks?

Rick Schultz used two scooter controllers in his Leopard and they worked 
quite well with the scooter motors he uses in that tank.  They are rated 
high enough to handle the load and are inexpensive because of the mass 
market for them.

> One controller for forward and one for reverse, on each motor?
> 2 contollers for each motor

I'm not quite sure how you're planning on connecting two controllers to 
the same motor, one forward and one reverse, without using some relays 
to disengage one while the other is operating (lest you release the 
magic blue smoke from lots of things).

You don't need two controllers for each motor, one will suffice if you 
use relays to control the direction of each motor.  That is, attach the 
controllers to the battery to vary the speed of each motor.  Then, run 
the output of each controller into a Tri-Pact Speed Controller to 
control the direction of each motor and mix the joystick inputs.

The tricky bit is developing a mechanical servo linkage that will rotate 
the control pot on the controller in one direction regardless of which 
direction the servo rotates.  That is, the controller pot needs to go 
the same way when the servo goes in forward or reverse.  Alternatively, 
you can use a separate servo channel to control the speed of both 
controllers.  I think that's what Rick did and it worked well on the 
battlefield.

        Frank P.