Wobble Free Z-Axis Oldham Coupler and Hot-end Saver

This design will eliminate Z-axis wobble. At least it did for me. It also eliminates the risk of damaging your hot-end, bed, or glass surface in case of a Z-axis sensor malfunction.

First, the story. If you don't want to know "WHY", then scroll down a little bit to "WHAT".

WHY:

I was suffering from a Z-wobble problem. I tried a lot of things to fix it. I tried creating a tool for perfect alignment, adding bearings, moving the motor to the top, to the bottom, using different couplers, and a different lead screw. At first, I bought a 1204 from AliExpress that was too short because it has a part with no threads. Then, I bought a longer one, but it came bent. I tried different designs, but they were too big, or the results weren't good enough.

Covid gave me some spare time, and I decided to fix an old BB gun from when I was a kid. I fixed it and bought BBs to test it. BBs are perfectly round, so I had the idea to use them as bearing balls to create a "floating" platform for the Z-axis, and it was perfect on the first try!

It solved the Z-wobble, even with a bent or misaligned lead screw, and if you have a problem with the Z-axis bottom sensor or limit switch, your hot-end won't break your glass.

WHAT: So, for a better understanding, just take a look at the drawing. It basically consists of 3 platforms and 2 layers of spheres.

To build this, you will need 24 BBs with a 4.5mm diameter. These are very cheap, and even if you don't have a BB gun, I'm sure you'll find projects to add them. I also added a small amount of silicone grease to them.

BB link on Amazon. As cheap as $2.50. https://www.amazon.com/Daisy-Ammunition-count-tube-Blister/dp/B00279OFNA/ref=sr_1_1?dchild=1&keywords=bb+4.5mm&qid=1608847060&sr=8-1