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 damage your hot-end, bed or glass surface in case of a z-axis sensor malfunction.

First, the Story. If you don want to know "WHY", then go down a little bit to "WHAT"

WHY:

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

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

It solved the Z-wobble, even with a bent lead screw or a misaligned one, 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 spheres layers.

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

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