Denford Software & Machines

Hi to all,
I have bought an old Orac, in good condition but I am having problems with the stepper motors which do transfer faults from the X to the Z axis if I swap over the drives. There are 4 LEDs on each drive board, 3 red with a green LED uppermost and sometimes the machine on power up has the middle red LED on and when I E stop, the green LEDs switch on and the red LED goes out but when I try and drive an axis the green LED flickers and then goes out (sometimes a red LED lights up) and then the axis will move in one direction only irrespective of which direction key is pressed. Any ideas, ("dry joint" perhaps?) Just asking before I rip out all the O/E electrics and "modernise" it! Would be nice to get it to run a few simple progs to see what it is capable off! Also any ideas/suggestions as to which B/out board to use and which drives would you recommend (Geko)? This machine has the original Brown Pestell spindle control replaced by a Mitsubishi A024, will Mach 3 control this, I.E. constant cutting speed, spindle rotation reversal e.t.c.?
I am not an electrician by any means but am reasonably intelligent! and any ideas or suggestions wold be (very) gratefully accepted!
Regards,
Wayne

I think these are the manuals here:
viewtopic.php?f=15&t=561&hilit=parker

You're probably correct in it being an issue with the drive interns.
Try follow the tracks from the direction pin input and look for dry joints / corrision etc...
Also check around the bigger drive diodes / IC's for the same (it sounds a bit like something is using too much current if LED's are coming on/flickering when you turn on - remember that current is put to a stepper motor continuously so your symptoms will be there whether running or not)

I can't comment on Mach or what BOB's to use, but there are links and info on here from others who have used them