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sir-buckyball / chrome-gcode-sender

A gcode-sender application for Chrome/ChromeOS.
MIT License
61 stars 24 forks source link

Better way of "Zeroing" #28

Closed scales11 closed 10 years ago

scales11 commented 10 years ago

Question: What do you think about having a button to "zero" the position of the tool?

Situation: I boot the tool up, put my material down. I then, need to move the tool to a reference point on my material. I think the best way to do this would be to use a reference plate (something that is conductive and wired to the limit switches of the CNC). Once I move the tool manually (via your buttons/program) to the point where it hits my reference plate, I would like to set that point as the x,y,z "zero". Typically I accomplish this by disconnecting and re-connecting.

Any thoughts?

sir-buckyball commented 10 years ago

Once you have positioned your tool, the proper way to zero it is to set the workspace position register. For example, if you have it at position (0, 0, 0), you can send the command "G92 X0 Y0 Z0".

You can also split the command to do one axis at a time which is good for lining up against the edge of a piece. For example, you can move a 10mm bit to the left side of a workpiece (just touching), then send "G92 X-5" to set the X axis position to -5mm (accounting for the tool radius). This same trick can be used on the Z axis if you don't want to smash the tool into your workpiece.

For 3D printers, having a fixed coordinate system with automatic homing is very useful because the surface is always the same, but for milling the positioning is very much dependent on how you've mounted your workpiece.

I had at one point thought of trying to make it easier to zero, but I couldn't think of a simple enough button which was expressive enough for my usages. I always ended up just typing in the G92 command and confirming by sending a '?', which on my machine reads back the current coordinate position.