A different carriage setup. Maybe it will work maybe not.
I like the under verses over design of the belt travel. Keeps the drive forces close to the nozzle so it should in theory be for accurate.
How has the movement been. My pbc linear bearings are so tight in tolerance to the shafts that they are prone to chatter with even the hint of misalignment.
@Eclsnowman Thanks. I was trying to put everything under and only the steppers on top but that’s is impossible unless you have steppers with 100mm shafts. The movement sucks. these 65 cent bearings are not even worth the 65 cents. I need to get up into some $4 bearings. these cheep ones will score the shafts then have to replace the bearing and shaft again anyways. Other than that it slide well. I have 3 bearing in that carriage. This one should not need any spacers under the idlers as every thing is supposed to align up.
@Wayne_Friedt the hard part for me was trying to keep 4 bearings in the extruder carriage all aligned within tight tolerances to the 2 shafts. Its a lot of stacking tolerance for printed part precision. Especially with high tolerance bearings and shafts.
I ended up using orings in the snap ring groves on the linear bearings to allow some give. Also I dropped to 3 bearings like you are doing.
@Eclsnowman The orings were something you did not bought like that. How did you keep the orings from rolling off when shoving them into the holes and did it actually help with alignment.
@Wayne_Friedt yes they worked well. But I used pbc linear fl-8 bearings. They have a deeper groove.