The last couple weeks, I’ve made some progress on two, equally important projects. The first has been getting my first build of my four bar actuator build together.

The second has been finishing my new screw production building in Satisfactory :)

But while I’m sure you’re eager to learn all about my factory, I’m afraid this update is going to focus on the four bar actuator side of things.

This was a build of the design I showed toward the end of this article. I wanted to get a general feel for the stiffness of that design, and see how it is from an assembly stand-point.

I’ve never tried this all jewel bearing design before, and I was curious if there are any gotchas that would pop up in a physical build.

The cross-section below shows a slice through the axes of the drive side. The orange part is the drive arm and the two red arms are the passive arms. Those arms get held in place with a total of 6 balls….on this side.

And slicing through the axes on the other end of the linkage reveals another set of six balls and a bunch-o-cones.

So I was curious how much of a pain in the ass it was going to be to keep all these balls in place while I’m putting the preloads in place.

And I was pleasantly surprised! Since the preloads on each side attach to a central hub, I can assemble one side at a time, with gravity holding things in place well enough.

The only issue I’ve run into has been with the gear mesh on the worm drive.

It only takes maybe a pound (~0.5kg) of load to skip some teeth, and I can just feel that they aren’t well meshed. But this wasn’t a huge shock, since I printed these FDM with a relatively coarse nozzle (0.6mm).

I did attempt to print a resin set….