Tool Radius Compensation

[davidmb]

Hi, I've just got my machine to the point where I can use it to cut the rest of the parts for it's own completion. I'm using TurboCAD and ACE to get my gcode, but I'm a bit confused by the tool compensation codes. When I cut, I get the center of the cut where the part outline should be, reading the notes on tool compensation seems to make a dependance on the direction the tool travels around the part as you would expect, but how do you get ACE to output the gcode in the right order or am I expecting too much of the software.

In the interim I'm drawing my tool paths larger or smaller by one tool diameter, I know this isn't strictly correct but it works for now.

I'm using EMC on Linux as the control software.

Any experiance, hints or tips would be welcome.

[Rekd]

If your controller accepts CRC then add the rad or dia (depending on the controller), to the dia offset and you should be good to go.

[Bubba]

davidmb
Tool compensation in TCNC is LENGTH compensation NOT diameter (radius) so what you are doing because you are using ACE is exactly correct!
If you want to do a drawing, and have the gcode correct for the diameter of the tool that you are using, you need to upgrade your cam program (and of course I have a recommendation) to something like SheetCam. It will develop the tool path based on the diameter of the tool you specify.
ACE is an excellent way to do it to begin with but as you have found out, you have to do your own offsets to get the toolpath you desire.

OOPS, read that as TCNC instead of TurboCad, but the comments still apply I think

[ger21]

but how do you get ACE to output the gcode in the right order or am I expecting too much of the software.

This is the problem. You can try making sure your CAD drawing is drawn in the exact order you want to cut, and make sure you turn off optimising in ACE. It may not work, though, ACE does funny stuff sometimes.

Assuming you can get ACE to output everything in the right direction, you'll then have to add G41 and / or G42 code to the gcode file, as well as G40's to turn comp off. And, when doing the drawing, you have to include lead-in and lead-out moves where thetool offset occurs. You can use SheetCAM, which will automatically do the offsets for you, as well as give you more control over cutting direction. It won't use G41/G42, it will just automate what you're doing now. I don't know of any inexpensive software that will give you gcode including G41/G42.

[rweatherly]

Does Mach2 do tool radius compensation?

Richard

[ger21]

Does Mach2 do tool radius compensation?

Richard

Yes, it does. Art recently made some changes and added an advanced compensation mode that works really good.

[MDU]

What can be the problem when using G42 on a CNC lathe to make a 5mm radius and T and R offsets have been applied correctly?