First post here & hoping someone with Acramatic 850SX knowledge may be able to assist.
We have recently purchased a Sabre 2000 with an Acramatic 850 SX control and Fanuc AC servos. During transit (and that may have been during one of several transits before it arrived here), the Z axis servo motor was removed to reduce the overall height & the head placed on a chock. Unfortunately the head was not strapped to the table & the table appears to have moved causing the head to fall off the chock. With no brake motor on the ballscrew the head dropped, shearing the bolts on the bottom ballscrew bearing bracket, smashing the counterbalance cylinder bracket & punching the linear scale reader head through the bottom of the scale. Fortunately the ballscrew didn't run off the end of the thread (no lost balls) & the lower linear bearing carriages were still half engaged with the rails.
The bearing & counterbalance brackets have been replaced & a replacement scale ordered but, having now perused the electrical schematics, I noticed that the scale on the Z axis was an option, with the motor encoder feedback via the Fanuc AC servo drive being the standard. While cleaning out the electrical cabinet I came across a feedback cable to connect between the drive & the control (part of the provison of wiring for a 4th axis which is not fitted).
It would seem reasonable to be able to disconnect the damaged scale from the control at the Molex(?) connector just below the A850SX card cage & replace it with the feedback cable I found connected to the Z axis drive.
Would I need top change any parameters in the control related to line counts, count direction, soft limit values or referencing behaviour (the scale fitted had distance coded reference marks - though I don't know if the A850SX could use those?) There is a parameter listing present that may or may not be applicable ( it is a faxed document from Cincinnati Machine UK, but it only refers to 500, 750 & 1000 capacity machines) which mentions "Linear resolution Low/Med/High" and "Rotary resolution Low/High" - also "Low limit/High limit" for each axis (soft limits ?) but nothing apparently to do with "number of pulses per unit distance" (so the encoder count would have to be matched to the ballscrew pitch ?) or for "count direction" (need to swap A and B channnels over in the connector to reverse count ?)
Being able to jog the Z axis via the control would make aligning the replacement scale easier than having to rig up a battery box & temporary enables etc.
I have not yet applied power to the machine - with no Z axis feedback I would expect it to either fault out due to feedback monitoring straight away or run away when the drive was enabled.
Also, there were no operating or programming manuals with the machine. A hand written list shows the control software to be "MC Rel 1.2 M2C 9/20/94 Sabre Vert (ERO) 91202721 R2 13 June 95" The options include :
Ext. Prog Store
5 digit spindle speed
Axis error comp
Enhanced tool data
Could anyone supply .pdfs of the relevant manuals, please ?
Sorry for the long post. Any assistance would be greatly appreciated.
Coidan Graphite Products Ltd