After recently completing my ball turner project (See: https://poal.co/s/Machining/747134), I realised almost immediately that I would need some sort of tool post to hold a small button insert for turning small diameter balls in tighter confines. I ordered a cheap 8mm button insert tool from fleaBay which came with a pack of 10 inserts of extremely dubious quality for under AUD$30 delivered (for reference, a pack of 10 TCMT inserts for my normal lathe tools that aren't junk cost close to AUD$100). Needless to say, the inserts are hot garbage, but they'll do for now. Anyway, I found some scrap steel lying around, mostly offcuts from the ball turner project. A length of shaft was tapered down to around 9mm (leaving some room for missalignment) and a hole was drilled into the base plate to locate the post for welding. It was a light press fit. https://pic8.co/sh/dKJ33E.jpg The 5mm high dovetails were cut into the base first. https://pic8.co/sh/ST6PLQ.jpg Then the two parts were welded together with some functional but less than pretty welds. https://pic8.co/sh/lZJfef.jpg The top half of the ball turner with the button insert post attached was then mounted in the lathe and dialed in as close to center as it would go. The tip was then turned down to the diameter of the base of the inserts (about 7.5mm), and an M3 hole drilled and tapped in the end (after it was turned to the exact length to make the tool sit on center). https://pic8.co/sh/a9UiMm.jpg Some holes were drilled and tapped in the side of the base to mount an indicator standoff. I couldn't use the one from the main tool post, as the base was slightly thinner and the holes wouldnt' quite fit, so I ended up making a pin to screw in with a clamped bracket that doubles as an indicator touch pad. To set this tool up, you indicate it in to the center using a dial indicator mounted on the cross slide, then you can move the indicator into the ball turner mount, zero it, then move out the desired diameter plus half the diameter of the button insert. So, to turn an 11mm ball, I move the tool post 9.5mm (4.0 + 5.5) from the center possition. https://pic8.co/sh/EuIIsd.jpg This tool post will come in handy soon (it already has, I just haven't written that one up yet).