Great idea - I'll have to make a few for my lathes - Unimat 3, Sherline, and a South Bend. Have you considered flipping it over and drilling 4 more holes in the other end, perhaps fractional sizes to hold even more sizes?
Firstly thanks for watching. Secondly, that is a brilliant idea! I don't know why I didn't think of that! 🫣 I will flip it over and drill the other side with imperial size holes. Thanks. 😎👍
Well I've made one for my Cowells - but very different! I machined some cast iron bar to fit in place of the normal toolholder but it is cross-drilled in the same way. And it works very well.
For my Unimat DB, I made one to hold an 11 mm drill bit (useful for M12×1.00 threaded holes), plus a 1/4" hole for various useful bits. Very much appreciated!
Though there are similar items, I was surprised that there isn't anything commercially available. But then I figured each lathe will be slightly different and so it's probably better to make your own to suit. Thanks for watching. 👍