Re: Timing belts

Just wondering if a wire drive would work?
if it did, it has got to be pretty much the cheapest and simplist.

The same kind of mechanism as the old draughting table parallel motion.
with a shaft driven by the servo/stepper, with a plain cylindrical
pulleys at each end...

The wires are captive on the driven pulley... run to the carriage..
then to a fixed, adjustable idler at the far end and back to the drive
pulley..

I imagine it would be possible to build a machine almost as big as you
could imagine..

accuracy would be determined by the stretch of the wire under load,
the accuracy of the pulleys and the cleanliness of the drive
system... the pulleys could be enclosed with just a wiped, hole for
wire exit.

As I see it, the advantage over toothed belts would be that keeping a
wire cable clean would be much easier, a simple wiper would suffice.

Chris

..--- In CAD_CAM_EDM_DRO@yahoogroups.com, "mmeyers1111"
<mmeyers1111@y...> wrote:

> I'm building a 3ft by 4ft router. Has anybody successfully used
> timing belts to control gantry movement and could you recommend a

belt

> type and a supplier? Should I expect backlash problems controlling
> movement over a 4 ft distance? Other problems?
>
> The belts and pulleys seem to be relatively inexpensive, it seems
> relatively simple to implement, and gantry speed could be changed
> easily with pulley diameter changes. How come timing belts don't

seem

> to be used more for cnc router control?
>
> Mike