I have a 3624 (long X, short Y) Benchtop Pro machine (just the bones from Avid) that I am setting up. I have discovered a weird resonance problem with the X+ side (aka “right side” or “slave”) Y-axis slide. The faster I jog the axis, the louder it gets!
I have eliminated some variables:
- parallelism1: the 80mmx80mm cross-table extrusions are CNC machined, so the slide assemblies should be reasonably square and aligned;
- parallelism2: the 160mmx80mm X-axis backing extrusion is also CNC machined, so the ends should be square and the risers should be reasonably parallel;
- parallelism3: I set up the rails with a dial test indicator, so they should be as close to parallel to each other as can be reasonably expected;
- lubrication: bearing blocks and ballscrews have been cleaned and repacked;
- isolation: with the gantry (and Y1 or “master” axis slide) completely removed and out of the equation, the Y2 axis slide resonates on its own, even when moving the assembly by hand;
- support: I purchased a second set of feet for a total of eight, so the Y-axis slides are supported throughout their lengths, rather than just at the ends.
- duplication: no other axis slide has this problem - not even the Y1 “master” axis. The X-axis is SILENT!
I first suspected binding from misalignment, but I am now fairly certain this is not a thing. It’s not fun to disassemble, and even less fun to align, and I am certain that I have done as good a job as can be done, given the overconstrained nature of the design.
I suspect a bad bearing block, which must have been shipped that way. One out of the four seems to be less smooth than the others. Questions:
- Would that make the machine ring like a bell?
- Would it be better to change out all four than just one?
- Since Avid doesn’t sell HG15 bearing blocks in their online store (just 20mm for some reason), will just any HG15 bearing block fit the stock slides?