Improved y-axis carriage attachment for prusa i3

thingiverse

High tolerance rods and linear bearings caused excessive slack in my Prusa i3, leading to noise at any speed and build up of resonance in the y-axis belt even at moderate 40mm/s printing or moving speeds. The belt eventually slipped off from its pulley. I had low-quality rods provided by Replikeo in my kit, far from smooth. Buying high tolerance rods and bearings was too expensive for me. I also tried cheap high tolerance bearings in hopes the original were defective, but got the same results. To solve this issue, I preloaded high tolerance bearings on each rod. I had extra bearings, so it made sense to try. The preload setup works by using three LM08UU bearings on each smooth rod, with one bearing vertically offset .5mm from the others. This fix worked really well and now my printer's speed is limited by extrusion capacity only above 65mm/s. I've yet to find a moving speed upper bound. I had reduced my acceleration settings when trying to solve the "y-axis missed steps at moderate speeds" issue. I plan to revert those settings in the firmware and perform more testing. Print Settings: Rafts: Doesn't Matter Supports: Doesn't Matter Resolution: 0.25 Infill: above 26% should work Notes: The parts were designed to be printed with the flat part touching the buildplate. Make sure you rotate it in your slicer for this position. Instructions: You'll need: 6 M3 nuts and screws 6 LM08UU bearings (you already have three) Print the parts, fit the nuts with screws, then fit the bearings. Finally, assemble the y-axis on the smooth rods. A gotcha is where part "left.stl" has no room for long screws. Buy shorter ones, around 12mm should be good enough.