[EricH]

Originally Posted by mman1506

It would probably better to use some sort of brake pad and disc to brake that allows for some slip.

Originally Posted by Mk.32

Get some cheapo scooter disk breaks/disks for $20 or so a set and a small piston to drive it?

If it was up to me, I'd do some looking into the appropriate calculations for the force you need to apply for that sort of thing. The calculations are pretty simple, if you happen to have the ratings of the brake pads, as I recall (I don't have them really, really handy, though, or I'd post them--it'll be a couple of days or so before I can post them up).

Now, this is assuming that the intended application would allow for some slip. If, OTOH, you need NO slip, then any brake/clutch type as discussed will need to be designed to hold more than the expected force needed to stop the robot from moving, lots more force.