Milling bit not perpendicular to spoilboard

I milled the holes for the t-nuts for mounting clamps yesterday and I was sitting on my stool looking from the front of the MPCNC and could see that the bit was tilted pretty significantly to the right. The router is not perpendicular to the table.

I have an Ender 3 V3 SE and they are known for their Z-Axis being tilted back and not perpendicular to the print bed. Could this be the cause of my problems? Could the print be bad?

The core is tilted like this, the image is a little exaggerated. In the Y-Axis, the tilt is not very pronounced, possibly a little pointing back at the bottom of the bit compared to the top.

The X-Axis is the biggest problem, it is pronounced with the bottom of the bit to the right of the top of the bit. The right part of the core is most out of square when measured with a t-square. The middle possibly a little less so and the left almost perfect.

How can I fix the perpendicularity of the router?

You can put shims between the router and the bottom piece of the mount to get it perpendicular.

Is it that the router is tilted relative to the Z axis or is it that Z isn’t perpendicular to X and Y?

It’s the Z, I placed my t-square on the spoilboard with the ruler part against the inside of the 2 brackets that hold the router and it wasn’t square, there was a gap larger at the bottom than the top…

I decided to print another core. Hopefully that will fix most of my problems.

What is a good material to use for the shims?

Mostly tape. Or a cut-up soda can. :slightly_smiling_face:

I calibrated my Ender by doing the auto bed leveling, then adding PLA shims where there were low spots in the corners and also added PLA shims under the gantry mounting point

The new print is almost perfectly square on the left middle and right backs of the core.

If that doesn’t completely fix it I will try the cut up can approach.