Bearing Sizes
All bearings are available in in both standard (0.2mm) and wide (0.3mm) clearance versions. I recommend standard clearance on a well z-calibrated printer.
629: 6 x 19 x 6 mm (standard / rim / square axle / rim + square axle)
689: 9 x 17 x 5 mm (standard / rim / square axle / rim + square axle)
687: 7 x 14 x 5 mm (standard / rim / square axle / rim + square axle)
685: 5 x 11 x 5 mm (standard / rim / square axle / rim + square axle)
608: 8 x 22 x 7 mm (standard / rim / square axle / rim + square axle)
609: 9 x 24 x 7 mm (standard / rim / square axle / rim + square axle)
6000: 10 x 26 x 8 mm (standard / rim / square axle / rim + square axle)
6002: 15 x 32 x 9 mm (standard / rim / square axle / rim + square axle)
6004: 20 x 42 x 12 mm (standard / rim / square axle / rim + square axle)
Background
Having tried a number of different bearings on the Thingiverse.com, I found that they quite often needed to be printed at high resolution, didn't spin easily and were not very robust. That said, some of the designs were mechnically beautiful.
I tried a few of the cylinder tumbler designs:
Bribo12 - https://www.thingiverse.com/thing:2349065
BoomZilla1 - https://www.thingiverse.com/thing:2746804
Drewbrewchan - https://www.thingiverse.com/thing:3506177
but could never get quite the result I wanted from my printer when running at 'impatient resolution' (a.k.a. 0.30mm resolution).
I designed my bearings so that they can:
1. be printed in place,
2. match common bearing sizes,
3. be relatively robust,
4. spin 10-15 times or more after applying WD40 or silicon spray and
5. be printed at 0.30mm resolution.
Once printed, just hold either side of the bearing and twist the outer wheel to free it up. For best results, a little WD40 or silicon spray should be sprayed onto the circular gap between the axle and the outer bearing wheel. I tried both and found them equally good.
As an aside, I only found the following bearings from GuppyK (https://www.thingiverse.com/thing:4851975) when submitting my own to the Thingiverse. I printed a set of the max clearance bearings on 0.30mm resolution and compared. Both sets work very well. I found that my 608, 629 and 685 spun better than GuppyK's equivalents and that GuppyK's 689 and 687 spun better than my equivalents. However, that could equally just be due to minor printing errors in either set.
GuppyK also has a set of rotary cylinder bearings for the larger sizes (https://www.thingiverse.com/thing:4821342).
The reason I created the bearings was to print my own spool cradle (https://www.thingiverse.com/thing:4982410) without buying bearings. As a result, I also added an optional small rim to the very edge of the bearing wheel. This prevents the spool from falling off the side of the bearing.
I also created bearings with an optional square axle (plus an optional rim set). The square axle x/y dimension is the same as the radius (not diameter) of the standard bearings.
629: 6 x 19 x 6 mm (standard / rim / square axle / rim + square axle)
689: 9 x 17 x 5 mm (standard / rim / square axle / rim + square axle)
687: 7 x 14 x 5 mm (standard / rim / square axle / rim + square axle)
685: 5 x 11 x 5 mm (standard / rim / square axle / rim + square axle)
608: 8 x 22 x 7 mm (standard / rim / square axle / rim + square axle)
609: 9 x 24 x 7 mm (standard / rim / square axle / rim + square axle)
6000: 10 x 26 x 8 mm (standard / rim / square axle / rim + square axle)
6002: 15 x 32 x 9 mm (standard / rim / square axle / rim + square axle)
6004: 20 x 42 x 12 mm (standard / rim / square axle / rim + square axle)
Interestingly, the cradle that came with my Prusa i3 Mini has real bearings which do not spin as freely as my own printed bearings on my cradle.
davehesketh
