Re: [CAD_CAM_EDM_DRO] Belt vs. Direct Drive

Doug Fortune wrote:

> > Over-constraint of the motion causes binding, and with a flexible
> > coupler, one end of the leadscrew is constrained (for tension and
> > compression) while the other is 'free' to move a few fractions of a mm,
> > relieving binding as the screw heats up, or the frame vibrates or
> > the original alignment was off, or whatever.

Chris Baugher wrote:

> I have a related question. Does a steel helical coupler offer any
> advantage or disadvantage to a rubber coupler?

I don't know.. I use steel/rubber spider/steel couplers which work great.
Very rigid in torsion (they don't 'wind up') and completely decouple the
motor from axial forces.

What scared me off (early aluminum) helical couplers was that they
tended to break, but I'm sure there must be good ones out there now.

However, I think they must have a little 'wind up' and hence a resonant
frequency, and don't completely decouple axial forces, so I use the
rubber spider type instead (I think the technical name is 'oldham coupling').

Doug Fortune
http://www.cncKITS.com

















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