Squaring with dual endstops

Mostly Printed CNC - MPCNC Troubleshooting
1

Hi everybody,

I am completely new to the MPCNC and this forum.
I have a finished working build and already did some nice cuts with it.

My problem is that it the cuts are not square ( was not important for the cuts I made so far )

So I checked the rails, and they are more or less square.
( I actually find it very hard to measure if it’s square, once the build is complete, any tips ? )

I have my end stops set at exactly the same distance from each corner.
The problem is, when I home the X and Y axes, on both axes, only one of the end stops gets triggered ?? So the gantry is obviously not square.

This brings up two questions for me:

  1. I tried tightening and loosening all the different bolts that should help to square everything, and yes, it makes a slight difference, but not enough. I mean, when I home the axes, one end stop gets triggered but the other one would need like 10mm more travel for it to be triggered. Could my printed parts be bad ? Any ideas ?

  2. I thought that the end stops would kind of “autosquare” everything by running each stepper ( X1 and X2 ) until both hit the end stop. But to me it seems that they both just stop when one of the end stops gets triggered !? So, I dont’t see how this could help with squaring ? I’ve read that maybe the end stops are swapped, so I tried to swap them, but same result. Also, I don’t understand how the board ( using Rambo 1.4a ) could even control only one stepper motor. When I look at the wiring diagram of the two steppers on one axes, I don’t think the board can control only one motor, right ?
    ( yes, I checked the end stops using the M119 command, they trigger correctly )

Also, in some posts I’ve read that it is important to wire the steppers correctly, meaning it seems important which stepper is X1 and which one is X2. If that is so ( even though I did not see this in the documentation ), how to tell which one is which ?

I also wonder if my steppers are even all running ? I mean, how could I even tell if X1 is running, but X2 isn’t ? ( it would still move the gantry, right ? )

I hope that a was clear enough, because english is not my first language, and all these technical terms are rather new to me.

Cheers,
Jacques

2

It sounds like you have it wired wrong. The X2 and Y2 should go to E0 and E1 motor ports.

https://docs.v1engineering.com/electronics/dual-endstops/

You need the dual firmware to get E0 and E1 to run. You can get it at MarlinBuilder releases. You can send M115 and it will show a version number, like v513D. If it is D, then it is configured for dual drivers/dual endstops

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3

OMG, how did I miss that !

So, basically, when using dual end stops ( version IS 513D ), the steppers get wired individually, not using the “spicling” cable.

I will have to re-wire everything as I used custom made cables. grrr …

Thank you !

4

Oh, bummer.

If you want to use it for a while first, you can make some “hard stops” to pull the gantry against to make it square while you enable the motors. They will move in lock step after that.

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5

Oh, yes, I see what you mean … but no :smiley: !
I want it to be “perfect”.

Thank you so much !

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