Newbie- What Postprocessor to use with USBCNC

[Peter Nielsen]

I´ve just finished retrofitting a Boxford 280 Turnmaster lathe with USBCNC CPU5B professional from Bert Eding (Eding CNC - PC based CNC control). I´ve bought Partmaster Lathe cam from Dolphin.
Do anyone here know what Postprocessor to use?

[John S.]

Peter,
Other than suggesting the Mach driver I can't help but I'd be interested to know how it works out as regards threading.
Mach, using the parallel port is useless. many who say they don't have a problem do have but they don't do long enough threads for it to be apparent.

John S.

[Peter Nielsen]

Originally Posted by John S. Peter, Other than suggesting the Mach driver I can't help but I'd be interested to know how it works out as regards threading. Mach, using the parallel port is useless. many who say they don't have a problem do have but they don't do long enough threads for it to be apparent. John S.

HI
I´m beginning to modify the Mach postprocessor, but I´m a newbie to lathe postprocessor, so I´m afraid of making mistakes. I´m done with the groups. Can you se if I´m doing right so far? I´ll try to attach a copy.
I have tried to make a simple job of turning an arc, but when I load it into USBCNC it tells me: Radius of end of arc differs from radius to start.

Regarding treadcutting I have not tryed it yet, but I have a sensor on my spindel, and I understand that it syncronise the startpoint of treadmaking (G76 in USBCNC).
Is it very expensive to get a customised postprocessor?
Regards Peter

[andre-dolphin]

I think the problem with the arcs is a question of the centre coordinates being either incremental or absolute.

Can you change the setting in USBCNC ? if not the post can changed.

The standard Fanuc post - T_F0TC, uses incremental - have a look to see the difference between under the macro section, here is the entry

#I = { (($YCEN-$OLDY)/2):XARC }

Absolute would be

#I = { $XCEN:XARC }

Hope this helps.

ATB
Andre

[rexcobey]

hi Peter Nielsen,

I am also using USB CPU V5 by eding cnc for my CNC Plasma/oxy fuel Combo with spendel on it, i also use sheetcam for converting my cad drawing to g-code and i am using the EMC plasma processor.

Also if you use this on cnc lathe try the EMC, but i am not sure if it work.
Please send me a feed back what happen because i am also planning to build one of cnc lathe using USB CPU.

Thanks