Cad/cam Problem

T

TomS

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Below is a screen shot of a split clamp block I'm making. I'm using the bore as my X and Y 0,0 reference. Top of the block is my Z 0 reference. My mill cuts the outside profile as it should and I can chamfer the profile with no problems. Using the same X, Y and Z references to chamfer the bore the cut is not on center. I've double checked to make sure I haven't lost steps between operations, which I haven't. Set up the gcode files to cut both the profile and bore chamfer cuts as one operation and separated them into two operations. No difference, still wants to chamfer the bore off center. Not sure what is going on. Anyone have any thoughts on this?

For info I'm running Mach3 version 066 and D2NC for my CAM software.

Tom S.

Screen Shot 04-23-16 at 07.25 AM.PNG
 
Are you using absolute or incremental I and J offsets? Look at the G code and see if the arc center is in the same place on both the pocketing and chamfering operations.
 
JimDawson said:
Are you using absolute or incremental I and J offsets? Look at the G code and see if the arc center is in the same place on both the pocketing and chamfering operations.
Click to expand...

I'll check it out. What I don't understand is why the difference when I'm selecting the same X/Y reference.

Tom S.
 
I agree, it makes no sense. You need to find out if the problem is in the G-code or Mach3, at least you'll know where to look to try to resolve this.
 
Not an answer to your problem but version 066 has many issues.
062 is the most recommended version and will save you some problems later.

Ray
 
JimDawson said:
I agree, it makes no sense. You need to find out if the problem is in the G-code or Mach3, at least you'll know where to look to try to resolve this.
Click to expand...

Here's my gcode file. Not sure how to interpret the I and J parameters.

Thanks for your help.

Tom S.
 

Attachments

  • Periphery and Bore Chamfer.txt
    1.3 KB · Views: 12
rdean said:
Not an answer to your problem but version 066 has many issues.
062 is the most recommended version and will save you some problems later.

Ray
Click to expand...

I've read that too. Up to now I've had occasional issues pop up but haven't had any major problems. Mostly "UC100 not found" and program stops running gcode midway through a cycle. Maybe it's time to reload Mach.

Tom S.
 
My pleasure to help out.

G03 X-.7040 Y-.5682 Z-.0300 I.0000 J-.8800 F10.0
G03 X-.0321 Y-.8800 I.6720 J.5682
G03 Y.8800 I.0000 J.8800 <looks like the problem might be here, but maybe it doesn't need the X if it doesn't change position>
Try changing the above line to G03 X-.0321 Y-.8800 I.0000 J.8800 and run an air cut to see what happens

G03 X-.7040 Y-.5682 I.0000 J-.8800
G00 Z.8750

M05 (stop spindle)
M09 (all coolant off)
G00 X0.0 Y0.0

M30 (end with rewind)
 
It is hard to tell much from just g-code but I ran it anyway in Mach3.
No problems found the code ran fine and the center cut is at 0,0.
Will do a little more checking later.

Ray
 
Another thought is to change the the D2nc arc center mode to Absolute rather than Incremental.

Because the hole center is 0,0, you might get away with changing the following line

G50 (reset scale 1:1)
G91.1 (IJ relative arcs) change to G91 (IJ absolute arcs)
G20 (inch mode)

Not sure how that would affect things
 
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