Re: [CAD_CAM_EDM_DRO] shaft torsion ?

Dave:

We used that same design on CNC panel saws over a length up to 14 feet. We
used something like a 1" diameter steel "hollow rod" and put no more than 3
bearings along the length. At each end was a pinion gear which meshed with a
small rack gear. This was used as a stabilizing system for the pressure beam
which was driven by air cylinders and it kept the beam straight. Since you
are only going 5 feet the 1" hollow rod should work fine. You might want to
put a couple of bearings along the length to help stabilize it. Where is the
drive point located? It is toward the center of the the rod or at one end
of it?

Randy A.


In a message dated 3/18/2008 7:58:07 A.M. Eastern Daylight Time,
dave_mucha@... writes:

Hi all,

5 foot wide gantry on a plasma cutter.

I want to run a shaft across and turn two spur gears on racks.

I am thinking about using 1/2" CRS as the shaft with the servo on it,
but then got to thinking about the shaft twisting.

Another idea is to use 1" OD steel electrical conduit to reduce the
twisting of the shaft.

I don't mind putting bearings along the length to eliminate any
whipping, but the twisting needs to be minimal.

Any ideas ?

Dave





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