- April 25, 2016 at 9:46 am #11280
I’m using the MPCNC as a router and I am trying to set up a touch plate for my z axis. Its basically a penny glued to a 3d printed holder. The z home works perfect, but I want to set the actual home to be lower than my touchplate. I’ve enabled eprom editing, but i haven’t had any luck with setting an offset.
http://imgur.com/ACbEZZg The touch plate in all its glory
What I want to do:
Hit home z and have bit touch the touchplate that is on my work surface.
ramps knows that my z axis endstop is 12mm too high
remove the touchplate
Run the gcode which starts cutting 12 mm lower than the touchplate
I can get around this by manually lowering the z axis then restarting ramps, or adding a move command to all my gcode to lower the z axis but I feel like there is a right way to do this.
AlexAugust 12, 2016 at 1:05 pm #16071
Hey I’m super curious if you ever got anywhere with this? I feel like adding a z height adjustment for the endstop in the ramps firmware is probably very doable.
I also think that embedding the penny into your table also wouldnt be that hard, since it is a CNC and all. You could just cut a hole the perfect size for a penny and then glue it in there. Wires to the side or bottom.
And on another node, I’m curious if the bit of the dewalt 660 is grounded to the AC power supply ground or something like that. How cool would it be to check for conductivity against ground and not have to attach some connector to your bit every measurement.August 16, 2016 at 4:09 pm #16248
I’m just using a thin piece of sheet metal. Aluminum foil would work, it’s just not very durable.August 17, 2016 at 7:39 am #16253
This must be far more accurate then a conventional mechanical lever end stop. Might have to change mine out.August 17, 2016 at 8:44 am #16256
Touch plates are good for stuff that moves, like the top surface of stuff we’re cutting. For the x and y, a switch works just fine.August 24, 2016 at 1:10 pm #16648
Did you find a solution to set the z startpoint 12mm lower then the touch plate? If so, how did you solved it?
Is it possible to do what the creator of estlecam has done, but in ramps (https://www.youtube.com/watch?v=bhZdbgM6S70&feature=youtu.be). I would like to find the z, x and y start point on the workpieceAugust 24, 2016 at 1:20 pm #16649
No, I just use a really thin touch plate. For what I use it for, the .25mm isn’t that big of a deal.August 24, 2016 at 11:54 pm #16673
Many this would do it for the Z – check the part about Multi-Pass Cuts:
http://www.akeric.com/blog/?p=3603January 5, 2017 at 9:55 am #24378
If you haven’t resolved this, you can home Z like you’ve said then send this command: “G92 Z12”. Change the 12(mm) to whatever your touch plate thickness is. 0 will now be the surface of your material.January 6, 2017 at 9:06 am #24431
Brilliant! Thank you, this was just what I needed.
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