Improve the printhead drive system
The short drive belts are a complete nightmare, and should be relegated to the bin.
Just stick the steppers right on the end of the shafts! Here is how:
This modification has the following benefits:
1) No short belts, so no need to constantly fight to keep them tensioned
2) Instead of each axis having 2 belts in series (compounded backlash error), you only have one. So backlash is much reduced.
3) Reduces motor noise a little by putting some material between the main case (which acts like a loud speaker) and the motor
If your belts are already perfectly set up and tuned, you wont notice a really big improvement with this upgrade. But it will stay
well set up much better, and if your system has a lot of slop in the short belts you will discover a big improvement in print layer to layer
repeatability (noticed most on large flat vertical walls).
Note that often the ground steel axial rods are cut by hydraulic guillotine. This tends to deform up to 10mm of both ends of the rod. So make
sure you cut off 15mm of BOTH ends..THEN trim it to length. Otherwise you may well find that one end wont fit through the bearings.
The tolerance I suggest is tighter than the standard bars, so you will need light oil and a “wiggle” each bar through the bearings. Dont expect
them to just slide through with no resistance.