dummy - GT2 16tooth and 16toothless idler by BETLOG

Last crawled date: 3 years, 1 month ago

I downloaded a GT2 pully from somewhere, I thought it was accurate.
I discovered that not only were some of it's dimensions different from the actual idlers I had in my possession, but that the flanges and channels around the bore were completely incorrect.
When designing I often rely on the accuracy of these small dimensions... eg: how big a washer, bolthead or spacer can be before it is no longer bearing only on the inner flange and therefore causes friction on the outer (spinning) components.
So I made this from scratch. It's not 100% accurate, as apparently there is no exact specification document online that I could find, but I have measured the critical bearing surface around the M3 bore, and the various gaps and protrusions surrounding it, and have modelled those accurately enough for me to consider useful to use as a basis for design at the ~100micron resolution level.
TL;DR; it's not to print, it's to design around. AFAIK it's the most commonly available idler of it's kind on aliexpress.
2018-02-02--16-00-31
deleted 806 kb stl from 01/30/2018
added new file - includes added detail to bearing (3x6x2.5mm MR63ZZ) construction and it's mounting within the idler. Details of the bearing's side profile (the ZZ, the part that protects and retains the actual ball bearings) are still not totally correct; without getting my microscope out I had to measure and guess a little under about 8x diopters of magnification, but it's still pretty accurate as far as what the bolt can bear on without binding the rotational freedom of the bearing outer.
2018-02-04--15-48-47
deleted 1 mb from 02/02/2018
added 0.05mm axial gap between bearing seats in idler casing.. just to keep the bearing from fusing with the idler. This makes it easier to eliminate duplicate vertices with much higher degree of accuracy without unnecessarily merging vertices from discrete objects.
TL;DR: they should 'split' (be separable) in your slicer AND your 3D editor better now.