Hello everyone !

I've been a CNC / Mach3 user for almost 15 years now ! Mach3 controls a home-made CNC.
As you might already think, I have issues... yes !
But first, a quick curriculum vitae so you understand why I'm asking questions here.
Oh and I'm french so sorry if it's hard to understand...

I've been taking care of my CNC from the beginning, reading and reading to find solutions when I had issues, and honestly it's been working like a charm for a 100% custom made CNC.
Last year I had to face a brain surgery (Myself, not the CNC  ) and since then it's really hard for me to figure out things in general.. and of course using and debugging a CNC is not really obvious... and it starts to make issues.. and I can't figure out what happens.
So here I am !

So as I said my machine has been working flawlessly for years, just a couple bearings to change here and there.
On my last project I'm facing a few issues :

-When machining yesterday, everything stopped randomly... it just stopped ! First time ever !
I still had power that's not the issue, the machine stopped (the router still spinning) and I couldn't control the cnc moves unless I restarted the computer. Then I could move the axis and re-zero everything to finish the cuts.

-Today I was machining a smaller piece. First sequence OK, I re-calibrate my Z axis (from top of the part to table 0 ) and start the 2nd sequence... Y axis is OFF !!! and when I stop all that, same issue as yesterday : I can't have the machine move, I have to restart everything !

And now I have no idea why but the distance from the "machine Zero", to the "Part Zero" is not the same as it was before. My "part zero" was X2.5 Y6 from the machine Zero because that's where I have some locating pins... not anymore ! Y is off, like 6.125" instead of 6.00" from machine zero ! (machine "zeroing" was done after the restart)

Any idea what could happen ? Of course I'm pretty sure I should give more details to have suggestions so feel free to ask and I'll do my best to answer.
I'm just not thinking of everything as well as I used to...

Thanks a lot for any help !
Ben


PS. the only thing I think I changed is the dust collection, I had a DIY cyclone collector (made out of wood and acrylic pieces) and It's been replaced a couple weeks ago by a ONEIDA Dust Deputy Cyclone 4". It's way more efficient ! I noticed a lot of static on the Dust Deputy though, can it be the problem ? I never noticed any static with my old setup..

PPS. I'll go take a few pictures of my setup tomorrow

Soo.. today action :
- reinstall the old dust collection system to limit the source of the issues
- try to zero as I usually do :
   * Zero the X and Y using the classic function/command : it moves until it finds the limit "magnets", stops, sets "machine origins" to zero
   * Go manually towards my usual "ski zero", it's basically a .25" hole drilled to insert a 1/4" pin (ref for machining on board)
   * use my traditional setup to have the router bit axis (of a 1/4" bit) aligned precisely to my 1/4" hole / "ski zero"
   * This is my new "work zero"

Z is not important there
I note the X and Y "machine" values of this "work zero" position on a piece of paper.

I move the router manually, just to move it here and there, slow, fast, front, back, left, right...
Then I go back close to my machine zero and click "ref all homes". no problems.
No i ask to go to my "work zero", it moves, X is OK, Y is OFF a couple milimeters !!!

OK maybe I didn't wrote the right numbers..
Do everything again.. same result : X is OK, Y is off again

I checked if Y have some rattle or a loose "something", nope !
I try again, same problem !

What surprises me is X (with his 2 motors) is always OK and accurate... The issue seems to be only with Y.

... and that was just a process I've been using the last 15 years to start a project !

I didn't even try to cut anything today since I can see my Y is wrong...
Any idea ?

pictures of the CNC

So.. couple new infos..
Oh and by the way my main language is not English... sorry if I'm not 100% clear...

When I REF ALL HOME (moves towards the X and Y sensors, Machine Coords. set to 0) , then go to a point I'll use as a reference for my project, I reach the point manually, make it the 0,0,0 ("project coords") and note the Machine coords on my notepad (x3.521 y2.745). Play with the G0 command all directions, then G0 x0 y0 → go back to the correct point, no issue.
Did that 3 times, same result → Good !

Now, lets imagine I close for the night because of a thunder just stopped everything while machining..

So I turn everything OFF, then restart the computer and turn the CNC ON.
Since "yesterday everything stopped without any advise" I use the REF ALL HOME button to go to the Machine Zero. from there I see my projects coordinates are x-3.521 y-2.745, perfect. So I go to X0 Y0 (project coordinates), expecting to reach my reference point... X is OK, Y is off by at least 1/8in... → NOT good

Tried the same thing a couple times, same result.

So I started to check the X and Y sensors, everything is OK : they turn ON where they are supposed to, not before, not after, right on point 10 times in a raw.

Man I have no idea what happens and what to check next.

I'm gonna start by using a lower speed to go towards the "machine zero" when turning the CNC on... it's never been an issue in the last 15 years !