25 Dec
2009
25 Dec
'09
6:06 p.m.
On 12/25/09, Roger Holmes <roger.holmes at microspot.co.uk> wrote:
Yep.
From: Ethan
Dicks <ethan.dicks at gmail.com>
Oddly enough, one of my side projects is tracking down a problem with
the original controls for a Bridgeport Series 2. One of the control
cabinets got packed with sawdust from an adjacent woodshop, so it
appears to be power-supply related (all the motor driver and pre-amp
boards check out, but only X moves; Y and Z make noise but are
stationary).
If I remember right the series 2 used stepper motors. One set of coils faulty? But on Y and Z seems strange.
Nope.
Maybe there's something in common for
the coils of both axes.
That is where I'm looking, but I'm new to the documentation, so I
haven't found it yet. I expect it to be there - it's an
experience/familiarity problem, not a documentation problem.
Rather less likely but the (woodruff?) drive keys
could have sheared, but again on both axes at once seems unlikely. Do the
motors turn or just go a tiny bit backward and forwards?
They do not move, but the motors do give a large amount of resistance
to manual turning (i.e., couldn't budge them by hand).
Of course its possible one of the axes could have
failed earlier and the
machine used for simpler jobs.
I don't think that's the case but I can't report that from personal
experience.
What I was told was that it worked perfectly until the
sawdust/overheating incident. It's clear that neither Y nor Z move a
micron now, and that's under direct manual control from the panel.
One of the things we did do was to swap the X cable onto the Y stage.
It moved perfectly. The Y cable wouldn't reach the X motor or we
would have tried that.
I am certain the Y motor is fine and the Y stage mechanics are fine,
too. It's something further upstream than the stepper boards and the
pre-amps since those have also been investigated and the problem does
not move to the X axis under any board arrangement, and the Y and Z
stage never work, no matter how the boards are arranged.
-ethan