Hi there!
I have built a V4, about 600mm x 1200mm. I remember when I initially did the squaring, it was kinda weird, not very repeatable. But in the end it was good enough.
Now today I noticed a very bad cut. I had 16mm MDF which I was cutting with multiple passes. Basically the cuts along the Y axis were perfect, the ones along X were skewed on the Y+ side, i.e. with every pass the bit was closer to Y0 than on the previous pass. I also noticed that the issue was much more prominent on the X- side than on the X+.
I then took a dial indicator and did some tests. I homed everything and moved the gantry to Y10. Then I moved the gantry to Y500 and back to 10 (so it doesnt run into the endstop) multiple times. The result: with every pass, the gantry came about 0.3mm closer to Y0 on the X0 side I then measured the Y500 position. Here, the gantry lost about 0.5mm every time. On the X+ side, it was very repeatable and I could not see any such deviation. This was all done without any load on the bit.
Just to be clear, with every iteration, the point moved further. After the 4th time (without homing of course), it was now 2mm off on the Y500 position. The movement of the axis is very smooth. I can move it by hand and dont feel any roughness. I checked the wheels/bearings, pulleys and the motor for uneven spots.
What should I check to narrow this down? Any ideas what it might be?
Thank you so much for any help!
