let's begin a list of needs for bearing variations
Slip Ring We need bearings that can transmit electrical power & signals - the concept is to have electrical conductors lining some region of the bearing such that continuity passes from a fixed member to a rotating mated member. Perhaps the simplest starting point is to have a metal film (such as nickel strip) see Amazon inserted before the metal balls, contacting the balls & having a tab passing to the outside or the inside of a race.
The thin strip in the image below sits inside the outer race of the green bearing near the back. With the right geometry the strip can be placed by hand and compressed into place with the balls. Design will require adjusted clearances for the strip to be added.
CV Joint We need a family of CV joints for various sizes & torques. An initial design concept shown below:
The joint should be tested & characterized for approximate speed, torque, & range of angles so users can make a functional selection. It should have a prescribed method to mate successfully with various rod diameters. This design concept is uploaded as cv joint on grabcad
- nylon balls on amazon
- steel balls 4.5mm on amazon
- steel balls 3/4in on amazon
Spool This design as of 2025 features some brainstorming, some prototyping, some study of needs, and has a little progress at each level but needs more. The goal: design a spool which can be rotated by a power tool, can fit in a drawer or hang on a pegboard, can be printed narrow to hold thin wires, and wide to hold thick cables, or otherwise adjusted to hold ribbons & tape-shaped supplies in the lab. The needs are very broad, but the best solution will accomodate all needs with just minor variations in the design. Those variations can be made into parameters in a model, and benefit millions of people. Jump to spool grabCAD post to get the version1 models. Can you identify your highest priority needs for the design? Comment on the CAD post. Can you build an updated version, or add a new idea? Print it out, post your build and add a tag "openspin." There are many ways to contribute.
key design variants can be broken down here by intended use cases
hub This design adds a bearing to your design. The printable model accomodates common bearing sizes with a press-fit (starting with 608) and allows easy parametric variation, and features a flange to attach the hub to a flat surface (starting with a steel box) and secure with fasteners (starting with M5 screws & nuts). It is logical to use common affordable bearings for suitable applications. The printable bearing above is not intended as a one-size fits-all solution to bearings. Each part has its place. So, access the hub model on grabCAD and adjust it to any shape of flange, number of fasteners, desired thickness, or bearing fitment. Get the CAD model here for solidworks, step, STL, and images.
casterBracket attach a caster to your 3030 aluminum rails. featuring this part in openSpin so we can have one post for wheels which contain a full OTS assembly for bearings. This printable model gives a solution for press-fit of the common peg-shaped inserts in the office chair style casters found at very good value online. Jump to cad model here
turntable This version-1 design meets a challenge: to allow 1 degree of freedom, support a high compression force, and distribute uneven loads by featuring a broad area. The challenge works! A fully grown man can stand on this plate (like a lazy-suzan) and spin freely, without breaking the plate. This was designed in 2020, and needs some improvements to align with our design standards and good-quality CAD modeling. It could also be improved in the strength where radial loads contact the center hole. (If it is fit onto a shaft, radial forces may cause it to deform or crack). But, it's a great starting point, it is geared towards parametric design and has functionality, low cost, and many applications. See turntable CAD model here!
