25 Dec
2009
25 Dec
'09
9:39 a.m.
From: Ethan Dicks <ethan.dicks at gmail.com>
<roger.holmes at microspot.co.uk> wrote:
If I remember right the series 2 used stepper motors. One set of coils faulty? But on Y
and Z seems strange. Maybe there's something in common for the coils of both axes.
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?
Of course its possible one of the axes could have failed earlier and the machine used for
simpler jobs. I once made a CNC program (prepared on the Apple 2) to machine elliptical
valves (upside down poppet valves) and the program only used X and Y axes. Similar jobs
must exist.
I wrote a similar program in 1979 to do a similar
job with an Apple ][ europlus (to a Bridgeport Series 1).
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).