RC Groups

RC Groups
    CAD/CAM
        Question Need advice on g92 use

#1 tr4252 Dec 06, 2012 03:52 PM

Need advice on g92 use
 
Hi,

Though I thought it would be easy at first, I'm stumped. What I want to do is "cookie cut" in some of my programs. I make multiple copies of the same parts frequently, and thought that using the g92 command I'd be able to cut a part, move to the next location, reset the origin with g92, cut the same part again, etc. etc. simply by copying and pasting the original part throughout my program at different locations.

I've tried writing the commands in different sequences, but no luck. I'm using a program called Millmaster Pro from Microkinetics with a 3 axis vertical mill.

Any suggestions?

Thank you,
Tom

#2 Roto Rob Dec 06, 2012 05:52 PM

G92 is a command for the mill controller. Normally people will generate the g-code. Then in a text, or g-code editor copy the parts g-code, then insert the g92 between the parts. Here is an example. Easy to get lost, so good idea to run a simulation if you have the software to do that.
http://www.cncezpro.com/g92m.cfm

You probably can also do the cut, and paste in the Millmaster software. Then you would need to generate the tool path for each part in the Millmaster software. I don't use your software. In mine I would just use the same settings, and just select the different geometry. Or I can select all the geometry in one operation. It will move the tool to the clearance height, and move to the next geometry.

#3 tr4252 Dec 06, 2012 08:46 PM

Thank you, Roto Rob.

I tried again, with a test that (I'd hoped) would cut two 1/2" squares side by side, with 1/4" between them. In the sample below, when I reached n050, the toolpath moved to the original X.5000, as if the g92 hadn't been there, and proceded to follow the path of the first part again back to the first origin point. Did I miss something in this simple example?

n000 g90
n005 g01 z-.050 f5
n010 x.5000
n015 y-.5000
n020 x0
n025 y0
n030 z.050
n035 x.7500
n040 g92
n045 z-.050
n050 x.5000
n055 y-.5000
n060 x0
n065 y0
n070 z.050

edit: Sorry it's compressed like this, in the window where I wrote this post all spaces were present; they seem to be deleted here.

Thank you,
Tom

#4 Ward Hagaman Dec 06, 2012 11:30 PM

Tom, the G92 command needs an X and Y value, in your example G92X0Y0. This resets the program coordinates to 0,0. Think of it as saying "I'm now at 0,0".

Another way might be to write the "part" program in incremental mode (G91), that way you can just write the part program once and put it wherever you want inside the "absolute" program.

#5 tr4252 Dec 08, 2012 12:55 PM

Rob and Ward,

Thank you for your help, you've enabled me to do the operations I need to do, through your advice.

Though I'm still having trouble using the g92 command, the suggestion to try g91 incremental mode is working well.

Sincerest thanks,
Tom


All times are GMT -5. The time now is 12:57 PM.