Re: [CAD_CAM_EDM_DRO] roller chain instead of screws or rack?

Tom Eldredge wrote:

> Dean,
>
> I used synchronous belting pullys and aircraft cable on an 11 ft. plasma
> cutter table gantry. Had trouble with vibrating belting as the speeds and
> position of gantry in relation to the end pullys. I think chain would solve
> that problem. Sounds good to me.

The systems I've seen that work use a cable or belt that lays on a flat
plate. There is a mechanism that picks up the belt, wraps it around a drive
wheel, and then lays it back down on the plate. The plate could be the actual
track the machine moves on. There are some problems with bending the
belt backwards on the rollers which shortens the belt life. Since the belt
is not going round and round pulleys in a standard belt drive scheme, it
apparently handles this pretty well. If you can make the belt wrap one full
turn around the pulley, you can eliminate the rollers. This may not work
except with cable or a very thin toothed belt.

I think this scheme even works if the drive pulley has a vertical shaft,
so the belt really doesn't 'lay' on the plate, but when it starts to flap, it
hits
the plate and the vibration is damped out.

Jon