Machsupport Forum

G-Code, CAD, and CAM => G-Code, CAD, and CAM discussions => Topic started by: dsnellen on May 02, 2016, 12:03:49 AM

Title: M40 Triplet File Issues
Post by: dsnellen on May 02, 2016, 12:03:49 AM

I am using a cheap NO switch to create a digitizing probe. The switch itself is a simple switch with a roller point often used as a limit switch. It is connected to pin #11 and 5v. The switch works perfectly. G31 probes down, the switch trips and a line is written to the M40 file. The problem is the Z height recorded is wrong! X & Y locations are correct but the Z height is off by about 0.25 or so. It shows correctly on the Mach3 screen. Anyone have any idea why the Z height would be recorded wrong?
Thanks Dave

Title: Re: M40 Triplet File Issues
Post by: Tweakie.CNC on May 02, 2016, 01:40:26 AM

Could it be that the G31 is storing the true point of touch in Var(2002) whereas the Z xis is actually using the specified deceleration before coming to rest ?

Tweakie.

Title: Re: M40 Triplet File Issues
Post by: dsnellen on May 02, 2016, 08:51:05 AM

Thanks for the reply. Possible. The start point is 0.25. The stored value seems to be 0.25 +/- the touch height. Using an F5 so I wouldn't think there would be a much deceleration. I have a lot of ideas to troubleshoot to include single step and watching the variable.
Dave