I just completed building my second 1515 machine and am running into an issue where when I run my gantry all the way to the back, the right side is short by 3mm. If I home the machine it comes back to the right place but every time I send it to the back the one side is off. Here is what I have tried - Made sure the x and y gantrys are square to each other using corner to corner measurements and the 3, 4, 5 triangle method. Loosed nut blocks to allow LEAD screw to settle into place. Loosed the y gantry frame at the rear (where it connects to the base) and ran the x carriage to home and back to make allow the frame to fall into place. Rechecked for square. Swapped the Y1 and Y2 motors thinking one might be off - the 3mm discrepancy stayed on the original right side. Flagged the couplers and the front tensioning nuts with tape to see if they were turning at the same rotation. They are. So what might be the issue? Any ideas?
Is your frame perfectly square? If not and its more Parallelogram-like it may explain the difference, or if one extrusion is a bit longer it may be square but end up a little short (cosmetic issue) Also check the grub screws on the shaft coupler for that axis, might slip on the leadscrew
I've narrowed it down to a lead screw. The frame is square - checked from corner to corner and using the triangle method. I just swapped the lead screws and the 3mm discrepancy that was on the right side...moved to the left side. I've taken phots of the screws with a ruler and overlapped them in Photoshop - they don't align and definitely seem to be different pitches. I'll send the photos to support.
Image of screws overlaid in Photoshop. I took a pic of both with a ruler below them and scaled them until the ruler matched. Different pitch LEAD screws
Customer support has an active ticket from you for the same issue. Closing this thread to avoid duplication.
