I was new to all of this in October of last year. Let me answer where I think I have decent answers.
First, I made some comments on another post that might be useful (MPCNC build in Montreal, CA - #6 by thejat)
I went with a 660. It was cheap and since I think the original design was meant for this router I went with it. As such I was able to find lots of addons on thinkiverse if needed. It is pretty loud though.
I think I comment on this in the above provided link. I don’t have them and for me its been working out okay. However, my suspicion is that I should have spent a bit of time installing these.
So this might help (Coordinates - V1 Engineering Documentation) but let me say the following. As a total newbie, after building the machine and doing a test with it, I literally asked the same question to myself out loud. I had trouble finding a simple answer in the beginning. Here is the ultra condensed version that I do (without end-stops or z-probe):
Disclaimer: For safety, always unplug the router. Personally, I don’t have it plugged in if my hands are anywhere near it.
- I used CNCjs not Repiter to control the MPCNC. I don’t know why but things just did not work for me with that software. More specifically, any type of zeroing I attempted to do either did not work or made no sense. When I switched to CNCjs it was like magic for me.
- Slowly move the gantry to the position you want to be the origin including Z. Normally this will be the lower left corner and the top of the material, but it actually can be anywhere.
- Personally, I then issue (through the CNCjs console) the M17 command. This turns on the steppers and for me “locks” the unit in place. I think M18 turns them off. Keep in mind when you turn them off your Z axis usually moves a bit or drops.
- Then through the console I issue “G92 X0 Y0 Z0”. This basically says, this is the origin. Normally, set all three to 0.
Corrections welcome.