cos The code ain't fanuc, maybe the feed is to high & the stepper is loosing steps how big is the hole (dia) try halving the feed.
going Z0 then Z9 to me is going away from the job Z0 = job surface & negative is normally into the job - but then if its not fanuc.... & whats that C1 I don't regognise that though I've not looked a the reference book so...??
It is a PNC controller, Its drilling cycle is slighty odd anyhow as you need to put Z as a positive to to achieve a minus! Also it drills the depth (in this case 9mm) from where the G01 Z0 FZ200 line is! So if G01 Z3 it would drill 9mm from 3mm above job
The 'C' is cycles, So In Fanuc terms 'Q' number of pecks.
Only an 8.5mm hole feedrate etc is fine, It drills a treat if i programme longhand, just can't figure out why the actual drilling cycle does not work!!
PNC urrrgggghh
well I've been forced to look in the fanuc book. G83 is peck drilling cycle so perhaps somewhere something is wrong with the peck distance or retact distance:?
perhaps it's a PNC "feature"
have you tried G81?
Perhaps Mr Magoo will have further insights I'm sure he knows the quirks of these controllers
ok. I know it's a PNC box .... but I asumed that G81 would be the same(ish) in fanuc speak it's the same as G83 but without the pecking, i.e, doesn't do a retract to clear the swarf
oh and Q in fanuc terms is the depth of cut for each cutting feed - but then that's irelevant to you.
when you use G83 does it indeed retract to clear the swarf? In fanuc the retract distance is set in a parameter not in the code, I just wondered...
Check if the display is reading correctly but the tool is mispositiong - this way you'll know if it's the steppers loosing position or the control s/ware misbehaving (although I think the terms "grandma" and "sucking eggs" could apply here ).
There is something in the back of my mind about a problem with a version of PNC milling s/ware that gave this symptom but I can be sure. I'll take a look in my archives & let you know if I find anything.