Re: problem milling a complete band on the rotary table

Message: 5
Date: Sat, 09 Jul 2005 13:46:26 -0000
From: "los_pachecos2002"

problem milling a complete band on the rotary table
Subject: problem milling a complete band on the rotary table

I am having trouble cutting a complete band with my rotary table. Let's
say I try to cut a wedding band, the item will not travel the full 360
degrees.

The band will look like a letter C. The area it does not cut can be
anywhere from 5-8mm wide....

I am using a microproto mill with a sherline rotary table and DOS based
control software.

Can anyone offer a solution?

[A couple of things come to mind. It may be a physical problem with your
rotary table, like grit in the gears. If it won't run all the way around
with roughly the same amount of force, it will stall the stepper motor. The
easiest way to check that would be by cranking it around by hand (you may
have to fabricate a little crank the same diameter as the stepper shaft). If
you feel more resistance in the problem sector, then some disassembly and
cleaning might fix it.

The other thing that could be wrong is your steps-per-unit settings.
(Remember that the unit in this case is a degree, not a millimeter - the
length of the gap will change with your stock diameter.) If you change this,
you will notice a change in the response to a command like G0A360. Making
the steps-per-unit number larger will increase the travel; making it smaller
will decrease it. You may have to fool with it a while to get it just right,
so that the G0A360 command causes a full revolution.]

Andrew Werby
www.computersculpture.com