Hello, just finished my MPCNC build. I went with the most recent firmware for the dual endstops. Everything is wired correctly, moves correctly and stops correctly with the endstops. I’ve read through Ryan’s squaring setup and something isn’t clicking for me.
Here’s how I understand what I need to do (Please correct me if I’m wrong!!):
Home X and Y (Using the controller)
Use a g-code program to run as large a square as I can fit on my mill with a pen
Measure the drawn square from corner to corner (X1 to Y2) and (Y1 to X2)
If the distance from (X1 to Y2) is, say, 1.5mm shorter than the distance from (Y1 to X2) than type M666 X1.5 into a terminal window
Re-run the square program, re-measure and adjust accordingly
Type M666 to get the current offsets and add them to the firmware (not sure where to put these values yet)
Does all that seem correct, or am I way off? Thanks for any help!
Yeah, that seems right to me. Just went through this myself on the lowrider. Had some square issues after using my tape measure on the setup.
The biggest square you can draw (I think any rectangle should be adequate) seems to give people the best results, even if the tool you use to measure it is less precise.
I’m a bit of a clown, though, and when I drew my smaller square is was NOT correct. I’m pretty garbage with a tape measure. Well, with most wood working tools, really. That’s why I like working on cars…loosen this, tighten that. I chucked in my 1mm mill and just poked holes at the corners of the square, so I could push my calipers into those, lol. Worked pretty well, and the larger square didn’t measure any differently that I could tell.
The only thing I would add to spare you a lot of disappointment is to first attach your router and work out approximately where a safe (0,0) point is. This is the point that you know the endstops can’t pass. If you square just using the pen mount and its clearance, then there’s a risk that you’ll have to do it all again when you realise that the spindle stops you from reaching the (0,0) point you’ve set with the pen… been there…
Ok, so without any adjustments I’ve got a difference of 0.5mm difference measured corner to corner on a 500mm square… Does that seem right? I’m assuming I should count myself lucky and not touch anything.
That’s close… When u make the adjusents for the duel endstops (say 1mm out of square) half of what is measured is the offset (1mm out .5mm offset) but .1% is close enough for anything I want to build.
Perfect! I read about the M666 but didn’t want to touch it with how close it is. Everything is way more square and tight then the first time around so I know I’ll be getting better results. Thanks Ryan!
Sounds like you’ve done a really good job. FWIW, when you do get around to messing with the m666, it doesn’t save right away. If you make it worse, you can set the adjustment back to 0 or just power cycle the machine and voila, right back to 0.5mm over 500!
Save with M500, and either make a note somewhere or save it in a copy of the firmware in case you ever need to reflash.
I use raspberry pi with all my printers / cncs. And my last built of a plasma table, is mach 3. I don’t think I’ll ever build another CNC using anything but a real-time controller…
I mean anything but mach or linux CNC is a compromise in my mind… I use mach3 but first tried to make Linux work and had issues. I am not a software guy. In the end I had issues with Linux seeing my parallel port… Paid for mach 3 but now realize how limited it is, especially with plasma. I am gonna try again with a separate SSD so I can always go back to what I know works
