Had a look though those available online and I couldn't find one generic enough to fit into the random assortment of spools I'd half purchased with a friend. So I made my own!

Highly recommend if your drill has speed adjustment that you set it on LOW!

Print one with a nut hole to secure the bolt and one without. Then stick a 125mm M8 bolt through the middle and tighten.

Have attached the SCAD in case you want to alter the bolt sizes.