Picture of DIY printable slew bearing

Slew bearings, Slewing bearings, and cross-roller bearings are all the same thing. The unique advantage is that they can take forces in every direction. Some bearings you can pop out the center if you push wrong. Some you can't use like a car wheel. Some you can't put a pencil in the hole and bend. Slew bearings can take a (relatively) large amount of all these forces, and do it in a really low profile (thin design).

I wanted a slew bearing for my robot. One slew bearing can replace about 6 parts in my current design and takes up a lot less room. Online slew bearings cost $120 before $60 shipping. No thank you! I got 100pc 1/8" ball bearings from Aliexpress for $10. This is a job for my 3D printer.

PS: There are four steps to this instructable but only 3 are displayed on the main page. Step 4 has the STL files and more.

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Step 1: Design

Picture of Design

I searched for "slew bearing cross section" and found

I modified the design to suit my tastes. The inside is two identical pieces. In the picture the inside and outside sit flush. In the photos I didn't plan so well and I had to chase bearings all over the place during assembly.

Based on the design I knew I would need 70 balls. In the end I used 68 to leave a bit more room for movement.

Dear Solidworks: please come out with a $500 edition for hobbyists. Sincerely, everybody.

DonaldB10 months ago

As a substitute for Solidworks (because the price is insane for the home user) I have been using Autodesk's Inventor Pro, which if you get a student account with them, (free) you can download the student version (also free). Then you just build and export as an .stl

XTL DonaldB10 months ago

Also note that FreeCAD can make these kinds of objects also.

aggrav8d (author)  DonaldB10 months ago
Yes! Thank you.
Gilius DonaldB10 months ago

Designspark mechanical is free

NRG4UandMe3 months ago

really awesome stufff !!!!

harvsch10 months ago

A very nice job, and an intriguing design.

Looking at it, I started to wonder. What keeps the balls from chafing against one another as the race turns? In a normal ball bearing assembly, the balls are kept separated from each other by a keeper. Without that the balls will peel into flakes. I realize that you are turning this at a fairly low speed, but if the balls are touching each other, I expect some of them are sliding instead of rolling.

geraldpaxton10 months ago

Trick...when setting balls or rollers, use a waxy grease to hold them in place, if need be, you can always wash out with solvent.

oliverkellow10 months ago

video please!!

aggrav8d (author)  oliverkellow10 months ago

Added to step 1.

tbutters10 months ago

This is great! I very nearly built something similar, but wound up laser cutting pieces from Delrin since I was concerned about printed races being smooth enough. But seeing this means I'll have to give it a try!

24Eng10 months ago

Awesome job using a 3D printer for something other than a bauble.