Summary

A simple 3D printed handle for a 1/4" extension such as:

https://www.aliexpress.com/item/Power-Tools-10PCS-Magnetic-Extension-Extend-Socket-Drill-Bit-Holder-Screwdriver-Extend-Socket-Bar-Rod-1/32636221884.html?

You can print this on its end and press fit the extension in. If it slips out you may want to add a touch of glue.

13/05/19: Added a little holster to store this on an Anet A8 - Now you dont have to lose it!