THC300/Mach3 Touch off issue

[jeremyrockjock]

After a reinstall of mach3 and THC300 the torch is moving out to the first cut and then moves up instead of down to touch off.  I have the motor direction set correctly and it bumps up to jog as it should. Any ideas what it is? I am using sheetcam to process gcode.

[jeremyrockjock]

After playing around more I found that reverse z axis under home/limits did the job.

[stirling]

I'm guessing you're using "home" touch off (as opposed to G31). Although what you've done obviously works, I'm guessing you have "home negetive" ticked as well which is kind of a double negetive way of doing things if you see what I mean. You could just have set set "home positive" i.e. home downwards.

Ian

[jeremyrockjock]

I have a floating head and am using a switch on z home input. I have read about the g31 somewhere but i am not sure what it is or how it works. If there is a better way I sure would rather do it.

[jeremyrockjock]

I cannot figure this out. Can someone explain what is g31 and how do I set it up? What is happening is the head is coming down to make the home z switch, zeros out the dro and then pushed harder into the metal for the Peirce height is stead of coming up. Also it is not doing my post variable offset even though I have set it in sheetcam.

[BR549]

Can you post a short section of your code that shows the HomeZ routine?

It sounds like you have problems with the Zhome switch sticking. Double check the function in the diagnostic page. Watch the Zhome led and trip the switch by hand. See that it changes state. Next make sure the state is what you need in your setup.

(;-) TP

[jeremyrockjock]

I found the g31 code processor in sheetcam and set it up. Now the torch is coming down to touch off and continues to drive into the plate. Under the g31 control should the input for the touch off switch be set on a different input? Mine is set on z home port 1 pin 13



How do I post my code?

[jeremyrockjock]

z home switch is working fine. I just have something ticked wrong

[BR549]

Open the code in notepad Copy a section of code then paste it into the reply window.

I would get it working with the zhome then when it is working ok switch IF you want.  Here it works equally well either way.  Six of one half a dozen of the other.

(;-) TP

[BR549]

Question,  If you set your Z to zero then from the MDI issue a G1 Z-1.000 F5, which way does the head go Up or down?

Just a thought, (;-) TP