Tramming issue - 1/4" Gap between Y2 from plate and X-axis plate

[Stevenlgts (Steven Linehan)]

I’m having an issue squaring my machine. I did purchase my Shapeoko 3 XXL used and no mention of issues were ever disclosed to me about squaring. I’ve decided to do a full squaring according to the assembly directions and replace the belts and wheels. I have a 1/4" gap between the Y2 rail front plate and the X rail side plate.

1. The black base frame is within 1/32" measuring the diagonals.
2. The distance between the Y1 and Y2 rails measured from the back and front are spot on.
3. I loosened the x-plate bolts (4 per side) and loosened the Y1 & Y2 front and back plate bolts (16 total). I moved the gantry so the x-plates contacted the Y1 & Y2 front plates. I clamped the Y1 and X (see photo) plates and the other side of the X-rail shows a 1/4" gap between the Y2 and X plates. I can pull it closed but it springs back once released. If I clamp the Y2 and X plates and then tighten the bolts according to instructions, once the clamp is removed the axis springs back and the gap re-emerges. The gap is present if I move the x-axis to the back it just is on the Y1 side.
   Looks like something is bent. Any ideas?
   Thanks,
   Steve
   
   
   
   
   

[Ed.E (Ed)]

Have you checked to see if your X rail is straight with a straight edge?

[Stevenlgts (Steven Linehan)]

Yes, I just did that and it ‘seems’ straight but my straight edge isn’t the best either. No matter how I tighten the x-plate bolts the gap re-emerges. I tighten the left side first then the right side first. It didn’t seem to matter. I do think the x-axis is bent. I removed the belts and anything that can provide a force and that didn’t make any difference either.

[MindlessCorpse]

It is likely you will need to loosen the endplates of the X beam and insert shims between the beam and endplates to make it align better.
A good option for shims is to purchase a couple of sets of blade type feeler gauges and use appropriate thickness blades to shim with.
After getting the X beam square, be sure to re-check how your v-wheels ride on the two Y beams, you may need to adjust those as well…

[Stevenlgts (Steven Linehan)]

I tried the feeler gauge technique. I thought it might have made a difference until I slid the gantry to the back of the machine and the gap re-emerged. I suspect if shimming is involved it’s going to take shimming both sides. I need to locate my other set of feeler gauges.
Thanks for your input.
Steve

[ScottsdaleSteve (Steve)]

See these threads from way back. I had the same issue. Shims in the correct places will make it square.

Help! 3XL base is square but carriage is not!

My 3XL was out of square when I first assembled it, in exactly the same way as yours is now. The ends of the “X” extrusion were not perfectly square, requiring shims as described in the following old thread: Not sure why yours went from square to not square, but perhaps it needs shimming…

Yet another xxl squaring issue

I had the exact same issue on my XL, though only a 1/4" gap in the same places (back left/front right). I don’t think you’re shimming in the correct spots. You need to shim the X rail in the places indicated (back of the left end; front of the right end). I used a stack of 3 slivers of aluminum from a Coke can in each spot and it closed the gap exactly. If you look closely, you can see the shim in the second picture. Coke can wall thickness is ~ .004" thick, so with 3 layers my total shim wa…

[ScottsdaleSteve (Steve)]

And you’re missing a V-wheel, unless you took it off…

[Stevenlgts (Steven Linehan)]

Just disconnected the left side plate, and found some foil shims from one of the previous owners (I’m owner #3). Removed the sneaky shim, still had to do some shimming but now it is almost perfect, front to back. Lesson learned, look for sneaky shims. It wasn’t that obvious, it slipped out as I was removing the side plate.

[Stevenlgts (Steven Linehan)]

I took it off as I was diagnosing potential sources of error since I replaced my wheels yesterday.
Thanks,
Steve

[Stevenlgts (Steven Linehan)]

Thanks for the information, Scott. I donated an old feeler gauge set to the cause and I got it shimmed!

[MindlessCorpse]

FWIW,
Once you get the few nuances “squared” away, (squaring, grounding and work table flex) I think you will find that to be a very accurate and reliable machine.
Enjoy!!

[Stevenlgts (Steven Linehan)]

Thanks again for your assistance! Ironically, I just addressed the grounding issue a few weeks ago. In my spare time, I’ve been learning the cam functions of Fusion 360. No lack of challenges!