This is an eccentric nut (aka a decentration post) to adjust the pressure on your wheels for your 3D printer carriages or other moving parts.
Design is based on
...さらに表示 the item sold by robotdigg.
https://www.robotdigg.com/product/626/Openbuilds-decentration-post
If you do not care to wait for the shipment to be delivered to your doorstep, just print it!
You will need 3 eccentric nuts like this to build the nice delta designed by Hadyn Huntley - Kumu-3D printer design: http://www.kumu-3d.com. In fact, 6 of those eccentric nuts, if you also use the back plate on the carriage for extra rigidity on the Kumu design.
