Fast bed level test pads (Prusa i3mk3)

thingiverse

Simple and fast pads for testing and setting bed level correction are a must for Prusa i3MK3. I primarily use PETG, so my test results reflect that. The outer lines of pads measure 240 mm x 200 mm, which eliminates the need for a skirt. Pads are a mere 0.2 mm thick, taking only six minutes to print. After assembling my kit, I followed the manual's instructions and everything seemed perfect. Live z adjustment was set at -180. I ran some test prints and discovered that bed level corrections were best with left at 0, right at -5, front at -15, and rear at -5. This setting produced excellent results, and it was crucial to have a clean steel sheet surface (I prefer using basic washing-up liquid like Fairy, followed by a good rinse and drying with paper). To ensure all corners are aligned as closely as possible, I follow this procedure: 4. I run these pads and obtain measurements with a digital caliper: left rear 0.22, right rear 0.24, left front 0.21, and right front 0.21. When I rub my finger against the right rear pad, it feels slightly rough, whereas the others feel smooth. 5. Correcting bed level again, I adjust settings to left at 0, right at -7, front at -15, and rear at -7. 6. A new test print yields measurements of left rear 0.21, right rear 0.22, left front 0.20, and right front 0.22. Rubbing my finger against all pads feels smooth. 7. I correct bed level settings again: left at 0, right at -8, front at -15, and rear at -8. 8. Another test print gives me measurements of left rear 0.21, right rear 0.20, left front 0.20, and right front 0.21. This is satisfactory for me, and I see no need to adjust all corners to exactly 0.2. Finger rubbing provides a smooth feel across all pads, and measuring results fall within acceptable tolerance. It's worth noting that when using a caliper, I rotate the pad and take several measurements before finding the smallest point. This is usually against the grain and in the middle. Perimeter crossing can add extra thickness to the perimeter area at these levels.