G Code and Mach2

[InventIt]

I'm having two problems with Mach2 and my gcode.

One
When I load a gcode file into Mach2 it shows the picture of the cutting pathes in the toolpath window. Well, they don't look ANYTHING like the part I drew in Autocad. I tried making the gcode from DXF files in both Mach2, Flashcut and Kcam. Sometimes it works, ussually it don't.

Second Problem,
If I CAN get Mach2 to show a good toolpath, when I go to cut it on the router it barely resembles my toolpath image. Some cuts are upside down, some are just in the wrong place.

What gives???? Any Ideas.

Also, is it normal for Mach2 to use up all my Vitual Memory space and make my computer unstable?

Thanks

Attached is the gcode text file.

[ger21]

From my limited experience with it, KCAM doesn't write good code too often (maybe it does, if you draw the way it likes you to). Downoad Bill's gcodein from the Autocad section here, and run you're code through it. Does it look like what Mach2 is cutting? I think your gcode is all messed up. If your using Autocad, try Bill's gcodeout lisp, or my gcode exporter macro (polylines only), both available here in the AutoCAD section, and see if you get what you're looking for. You could also try ACE from http://www.dakeng.com.

Gerry

[turmite]

inventit Mach2's display many times will not accruately show the part as it will be cut. I don't know if you are aware but the display screen is also 3d and you may be looking at it from an incorrect angle. I never look at my display but then I have alread traced the part back a few times in my cad system to watch it for mistakes.

Mike

[yukonho]

Sometimes I get weird shapes (rarely) but even when I do it still cuts the right shape.
Sometimes the cut path is offset from the path shown in mach2, but it always cuts the right path.
Sorry I cant offer any advice.
co

[fyffe555]

As others have suggested I'd try to produce a Gcode using one of the excellent ACad routines or ACE converter and see how that compares with what KCAm or Mach2 is producing.

What format are you saving the dxf in? Have you tried saving the dxf in a different format? KCam and ACE requires the DXF to be in R12 acad format (?, I think?). I've saved the same file test dxf from a couple of versions of acad, autosketch and quick cad as well as turbocad as R12 format. They're all different . ACE produces a different gcode cut sequence for each. All produced the same, correct end product though. Any other dxf format produced errors from one program or another.

You could try running the produced gcode through another simulator to see what's being put out by the various programs. I use CNCsimulator; http://www.cncsimulator.com/ A free program that while it has it's quirks is useful to see the toolpath and cut sequence animated in several dimensions. You need to watch out for the dimensions 'feature', it only works properly in mm, not inches, so run the dimensions in mm for everything, just enter your inch values in the mm units everywhere and its fine.

[InventIt]

THANKS FOR THE HELP EVERYONE. I tried Ace Converter, it works ALOT better than Kcam or even Mach2's import DXF feature. Getting good tool paths on most things now. Flashcut generates good gcode on simple 2d parts also (sometimes). Saving DXF files in R12 version helped.

Is there a good cad/cam software package that costs less than $500?

ger21,
I'm using Acad Lt 2004. Do you know if the lisp/macros work with LT version?

[turmite]

Inventit Bobcad is probably the best you can get for that price, and please note I said probably cause I don't know about all the different packages.
Mike

[ger21]

You can't use Lisp or VBA in LT, I don't think. But there is an add-on you can get that will let you use lisp I think. But it's $300+.


Gerry

[imserv]

Originally posted by InventIt THANKS FOR THE HELP EVERYONE. I tried Ace Converter, it works ALOT better than Kcam or even Mach2's import DXF feature. Getting good tool paths on most things now. Flashcut generates good gcode on simple 2d parts also (sometimes). Saving DXF files in R12 version helped. Is there a good cad/cam software package that costs less than $500?

Vector Cam is available for less than $500 to hobbyists.

http://www.imsrv.com/hobby

DeskCNC is $250. It will create cnc programs from your DXF files. It has pocketing, contouring and drilling, plus a bunch more.

http://www.imsrv.com/deskcnc

Fred Smith - IMService