I purchased the Z Probe and doing a measurement of the thickness of it, Shows .40mm, is this correct? THe reason I ask is because I am doing the z probe home through Repeitier and then going into my G code and putting in G92 Z0.40 for the offset, but it is barely cutting the wood in my vcarve. Not sure if I am doing this correctly.
I thought the spatula Ryan sells is 0.5mm
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If the touch plate thickness was 0.5 and you enter 0.4 it should be cutting 0.1 too deep… not too shallow?
Either way v bits are quite demanding wrt z height. Sometimes you may probe a high area, sometimes a low area. Without surface probing you can’t compensate for out of plane materials (besides, level compensation is out of scope of estlcam and the usual mpcnc workflow… I suggest looking at grbl and bcnc if this is needed… for example pcb milling). So then all that is left to improve the result is adjust z offset so you get a good balance of areas that are too deep and too shallow… optimized for the particular part and stock.
Alternatively you can run a face mill to level the stock, and do a tool change to carve with a v bit. This way will come as close to perfect as you can without surface probing.
biggest issue I have is the piece is a hobby wood only 3mm thick and making wedding favor magnets for hanging. So, can really surface this plywood. Just getting the best I can with it. Thanks!
But as far as programming this into Repieter, anything I can do to hardcode that Z probe offset so I dont have to keep adding the G92 after?
Could be my digital caliper accuracy off a bit. That is a thin measurement to do
If you just need that before every cut, there is likely a “pre-gcode” section in your cam software where you can add the statement. Then the line will appear at the beginning of every gcode file it creates.
For myself, I have a gcode macro in bcnc that does the plate thickness offset automatically. This involves reading the z position in software, subracting plate thickness, and setting z zero. Not sure if the same can be done in repetitier (ie a macro that can use current position as a variable), but if so then you have options.
You can store macros in Repetier Host but they’re called scripts. They are defined on the Scripts tab of the Printer Setup window. See the “Predefined G-Code Scripts” section here. You could have your probe routine and the G92 command on a macro button.
You could also build it in to your start gcode, but then you’d need to be ready to probe every job, which may not match your workflow.
If you can’t surface the wood (and I would never with plywood anyway) the surface a block to put underneath the plywood.
So if I were doing a bunch of (for example) heart shaped pieces, I would cut out the heart shapes first, then pocket that heart shape into a piece of scrap, firmly bolted down to the machine spoilboard. The pocket will have a flat surface on the bottom relative to the CNC, so the WORK surface will be flat relative to the CNC.
Zero the carving bit relative to the work to get the depth you want. Once you get a good working zero, run your gcode, returning to the same zero (at Z+3). Replace with a new blank, run it again. Perfect repeatability.
I guess that doesn’t really address the probe thickness. I use 0.5mm for the probe, and it seems to work well, but I also tend to carve about 1mm deep in Estlcam, and haven’t checked for 100% depth accuracy. Nothing that I’ve done is that sensitive to a bit of error.
That is a great idea! I am going to give that a try.