AT MY WIT'S END! DXF-> G-code -> whack

[Sporqster]

I am having a heck of a time writing g-code to run in Turbo CNC. I'm using AutoCAD 2000, and I've tried using both DAK's DXF converter and Mach2 both give the same result! see attached to understand the mayhem. what you see here is the dxf of the intended tool path (2.dxf) converted to G-code (2.txt) then converted back to dxf (data.dxf). as you can see, the arcs are going freakin' nuts!

I'm new to this and becoming very frustrated! I can spend the time to draw all my own tool paths if I have to, but is there some software that I can use for free or nearly that will just write reliable g-code?!? I can't shell out the cash for a full-fledged CAM program right now. I can't even afford to fix the A/C which is part of why I'm going nuts. I think I'm going to take a nap now.

[Al_The_Man]

I believe your problem is due to a wrong setting in your post processor for the G02 G03 commands, which is something called I/J inversion, This defines the relationship for the start of an arc or the centre point of arc. There are basically three settings, I/J is treated as an incremental negative value from start of the arc, I/J is treated as incremental positive value from start of arc, or finally I/J is treated as an absolute position, your result indicates you are not set to the right mode. I am not familiar with TurboCnc, so I assume someone will set you right who is more familiar with the program.
I had exactly the same thing happen on a machine that accepted DXF directly and all I had to do was set it to Absolute position for it to straighten out.
Al.

[ghyman]

http://www.cnczone.com/forums/attach...achmentid=1179

This looks good.
Haven't tried it on anything complex, but check out
http://www.cnczone.com/forums/showth...3&page=1&pp=10

[Mac T. Knife]

In Mach2, try changing the setting under the config tab, click on state, and look for "IJ Mode", change the setting, and rerun the code, and see what happens. I have mine set at incremental,,, not ablolute

[ger21]

Originally Posted by ghyman http://www.cnczone.com/forums/attach...achmentid=1179 This looks good. Haven't tried it on anything complex, but check out http://www.cnczone.com/forums/showth...3&page=1&pp=10

This one's a lot better. http://www.cnczone.com/forums/attach...achmentid=7768 read the thread here http://www.cnczone.com/forums/showth...6&page=1&pp=10

Be aware that neither may work in AutoCAD 2000, They both work fine in 2002 and up.

[ger21]

I converted your first .dxf in ACE, with I and J relative, used the gcodein.lsp to load the gcode back into autocad, and here's what I got. the same thing I started with.