Trouble with squaring trucks

Mostly Printed CNC - MPCNC Troubleshooting
1

Just got around to finishing the MPCNC (C) that i started about 2 years ago. The build volume is about 26"x26" and the frame is square. All of the parts except for the trucks (PETG) were printed in ABS.

The problem I’m having is that when I get the bearings set to where they should be the X and Y core rails shift so that there’s about .5" difference between the trucks when squaring. When loosing up the core clamps and trucks the difference decreases.

With everything loosened the red circled truck is sitting at 4 ¹/⁸" while its counterpart sits at 4". The blue circled truck currently sits at 5 15/16" while its counterpart is at 5 3/4".

I mentioned printing the parts in ABS because I’m wondering if the core is cupped from warping causing the differences.

Thank you

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2

That’s very possible. I have never printed anything that large out of ABS so no experience there to share.

I will say your numbers seem close enough that once you get the belts on it and start homing it the motors will square that up nicely. Once you get to that part as long as you don’t get any binding anywhere during travel you should be just fine

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