Machsupport Forum

Mach Discussion => General Mach Discussion => Topic started by: kitandcloset on December 09, 2011, 10:14:48 PM

Title: tool compensation
Post by: kitandcloset on December 09, 2011, 10:14:48 PM
I am needing some help.  I have a cnc router running mach 3 with cabinet vision cabinet software.  When we output our gcode from cabinetvision it may be a few days until we actually cut the project.  Our problem is we have our 3/8" cutters resharpened.  There's no way of knowing exactly what size tool we will be cutting with beforehand.  It usually is somewhere between 8.7 mm and 9.525mm, depending if it was sharpened once or twice.
Is there somewhere in the Mach software where I can enter the correct tool diameter for a job and somehow override the tool diameter that is in the gcode from cabinetvision?  If possible, please explain as I am not real familiar with the mach software.  Also if somebody has another suggestion or way to do this another way let me know.  Very much appreciated!

Thanks in advanced
Brent
Title: Re: tool compensation
Post by: Sargon on December 10, 2011, 05:35:05 AM
There is only one way to do this using tool compensation. I have no idea if cabinet vision is capable of it nor how to turn it on, but the CAM program must be able to output the GCode with tool compensation for it to work.

Once you have enabled tool compensation in your CAM program, you can use Mach3's Tool Table to input the diameter of the tool. Note that Diameter Wear and Height Wear are not implemented yet, AFAIK it won't be until revision 4 is released.

The reason the CAM package must be compatible is because Mach3 needs to know what direction to apply the offset in. It accomplishes this by using left and right compensation indicators in the GCode (G41 and G42), always with respect to the direction of the cut (ie with respect to the tool). The alternative is adding the compensation by hand - but this isn't recommended as you need a lead-in move for Mach3 to properly determine the offset direction, and it can be a pretty painful process for anything but a very simple part.

Hope this helps a bit.
Title: Re: tool compensation
Post by: ger21 on December 10, 2011, 05:48:49 AM
I've been working with high end cabinet software and big industrial routers for over 15 years, and using cutter comp is pretty much the universal standard, as everyone is using sharpened tools. You just need to learn how to set up Cabinet Vision to output the correct code, with proper lead-in and lead-out moves. I haven't used CV since testing the very fist version when they switched from DOS to Windows, so can't help you with the setup.