On Mon, 09 Jan 2006 23:39:09 -0600, F. George McDuffee
wrote:

On Mon, 09 Jan 2006 23:08:51 -0600, Jon Elson
wrote:

Hello, all,

We have a Bridgeport/Romi EzPath lathe at work that has a "rumble"
in the Z axis servo. I tweaked some pots on the servo amp and
got it to quiet down so that the machinist is real happy with it,
but I think it could be better. First, I have no idea what those
pots do, as the labels are beyond cryptic. There are 3 pots there,
VC, BL and CC. I'm guessing that maybe VC is velocity loop
compensation, and CC is current loop compensation. This machine
has the SEM motors typical on the Bridgeport machines, and drives
the leadscrew by a coarse toothed belt. I'm wondering if the belt
is wearing or needs the tension adjusted?

Anyone have a servo adjustment procedure for these? (It has the
servo amps that are roughly 4" square boards mounted on a bent
piece of metal, with the power transistors mounted on the bent
part. No sign of a manufacturer or model number on them.

Thanks,

Jon
=============
Ancient wisdom says "if it works *DON'T* f*** with it.

Updated version is "the better is the enemy of the good."

Uncle George

Indeed.

Im a machine tool tech by trade. And I make money on machines that had
someone with a screwdriver and far too much time on their hands.

Unless you know Exactly what you are doing...as George said so
eloquently..dont **** with it. If you got it running without a rumble.
(probably loop gain)...count your blessings and dont go for the gold.

Though..I could sure use the work.

Gunner

The aim of untold millions is to be free to do exactly as they choose
and for someone else to pay when things go wrong.

In the past few decades, a peculiar and distinctive psychology
has emerged in England. Gone are the civility, sturdy independence,
and admirable stoicism that carried the English through the war years
.. It has been replaced by a constant whine of excuses, complaints,
and special pleading. The collapse of the British character has been
as swift and complete as the collapse of British power.

Theodore Dalrymple,