606 Mini Bearing, with Rollers & Cage (not PiP)

This 606 Mini Bearing (17 x 6 x 6 mm) is entirely printed, easy to assemble and customizable. It is robust, tight, and runs very well. The parts can be printed on any regular 3D printer with a 0.4 mm nozzle.

Advantages 

This assembled bearing is more practical than bushings or Print-in-place designs.

• Lower friction under load

• It has tighter fits, since it doesn't require printing clearances (unlike PIP)

• You can inspect & finish the running surfaces if needed

• You can use different materials for the rollers (including FLEX!)

• You can optimize the rollers fit for your application, balancing tightness and friction. For that you can disassemble the bearing and change out the rollers.

Application Details 

• Fully functional roller bearing, with a proper cage to separate rollers

• It can handle decent lateral loads.

• The hollow rollers provide a little bit of elasticity; solid rollers are also available.

• Drop-in fit for any light 606 bearing application

• Not intended for high velocity/force/heat applications; use a normal, purchased 606 bearing for that.

Printing instructions

Material choice

For Races, Caps & Cage: PLA recommended, other materials should work but haven't tested it

For the Rollers:

• PLA works fine, it can be a bit noisy

• PETG is recommended, it provides a nicer feel and prevents binding over time under load.

• FLEX/TPU also works! Size the roller down a little bit. It makes the bearing dead quiet while it still runs (with a bit more friction). Great option if you need a very quiet bearing.  

Slicer settings

• 0.4 mm nozzle

• 0.15 mm layer height

• 2 perimeters, 15% infill

• No supports needed

• Key (Prusa)slicer settings that worked best:

  • Scarf joint on Contours 

  • Scarf joint on Inner Perimeters

• Check/control for elephant foot, especially the rollers

• 8-minute print time on a Prusa Mini or Mk4 if printed all parts at once

Post processing

Check the roller running surfaces on the inner and outer race for bumps/printing artifacts. You can run a small file on both roller running surfaces to take off any artifacts and smoothen the surfaces if needed.

Assembly instructions

Assembly Steps

1. Place the Inner Race & Outer Race down 

2. Place the Cage, with the ring down

3. Place 7 Rollers (small needle nose pliers work well)

4. Place & snap the Outer Cap on the bearing assembly

5. Place & snap the Inner Cap on the bearing assembly

Assembly Notes

• Do not lift the assembly before both Caps are snapped in place! The bearing will fall apart, and the tiny rollers will go everywhere. You can place the Inner and Outer Race on a small piece of painter's tape to keep them together during assembly.

• Lubrication is optional, it is not needed but makes the bearing run a little nicer.

 Step 1                                         Step 3                                           Step 3 complete                     Step 6 

Exercise the bearing

Exercise the bearing a few turns to run it in; you should be able to see the rollers & cage move relative to the inner and outer race.

Disassembly steps

You can disassemble the bearing without damaging any parts (to change out rollers): 

1. Remove the Inner Cap: There is a small gap between the Inner Cap and Inner Race; use a small flat head screwdriver to catch the gap and twist/flip the Inner Cap out.

2. Remove the Outer Cap: slide a small knife in the gap between Cap and Outer Race and give it a light twist, the cap should come right off. Be careful not to cut yourself. 

Roller Variants & Fit optimization

Included are Hollow & Solid Rollers. You can XY scale the rollers in the slicer to optimize fit (leave Z as it is). The nominal diameter is 2.3 mm, scaling up or down by 2% will tighten or loosen the bearing fit (+/- 0.05 mm diameter).

Revision History

Version 1.0 - April 4, 2026: Initial public version.

Designer's note

This new design is based on the same general concept as my 608 Bearing below. I was curious if it would go smaller and the answer is yes!  Let me know in the comments if you're interested in any other (larger) bearing size; the general concept is quite flexible for different sizes,