Losing steps and/or skewing along X axis travel...?

So, I didn’t realize this was happening because until today I wasn’t running across the whole length of the axis as I was doing small tests.

I ran a program to put some pockets into my waste board and I split the programs between drilling holes for recesses and for the actual hold down inserts. In the second photo with all the scribblings between holes, the middle row is the distance between top and bottom… which is pretty steady with some minor variance, but the top and bottom rows have what I would consider significant variance - mostly because the circles aren’t “perfect”, they are skinnier across X versus Y.

I went back to the pen and the crown and noticed that the circles on that weren’t perfect either. Same issue with the circle below the cross being skinnier across the x axis versus the y.

I’ve included a bunch of photos. If there is something specific I can snap a photo of, please let me know.

Overall, it just looks to me like the x axis isn’t traveling “at full capacity”.

Not sure of what/how I can fix this issue… I kind of think it might be that the x axis motors aren’t getting enough juice (??), if that is the case, I’m not sure how to adjust that since the steppers on the board do not have a trim pot on a typical set of A4988 type drivers, that I can find. If not this, then any other thoughts as to what might be causing this?


BTW: V1 kit parts w/dual firmware. 660 router. 1/4 two flute flat end mill. Depth of cut per pass was 0.0625 inches.
36" x 36" x 3.5" build. Squared the diagonals of the machine to within a 32nd of an inch during the build.

Bump due to massive edit of initial post.

I’ve checked and tensioned all the belts as best as I can.
I’ve made sure there is nothing obstructing movement.

I spent the better part of 3 hours (O_O) looking around at all the bolts and printed pieces, the belts, tensioners, pretty much everything… except…

I’m. So. Dumb.

There was something rubbing… EVER SO SLIGHTLY. The cheap aluminum L-metal I’m using to keep the wires off the work area… ugh.

Goes to show… something something I’m dumb. But I raised it up fixing the issue… no more skipping. (O_O)

I would power everything off and grab the bit with your fingers. Wiggle it in the direction of the Y axis. I’ll bet that it has some more play (wiggle room) along the Y axis than it does along the X axis. You may need to slightly tighten a tension bolt to reduce wiggle.

Just a guess but that is where I would start.