Thread: Floating reamer holder

I designed and made this reamer holder a while back. It is a different approach to the conventional floating reamer holders in that it rigidly holds the reamer but is adjustable in all directions. The reamer is dialed in perfectly concentric with the lathe centerline before cutting, both on the pilot shank and the rear reamer shank. There is very little need for pilot bushings with this holder.

It can be adjusted in 4 directions from the rear adjuster set and also for angle in 4 directions from the front adjuster set. There is a spherical face between the two that allows this angular change but still have high rigidity when clamped. Chambers cut with this measure true to the reamer and have zero runout.

I should say that my lathe tailstock has had a fair bit of fettling to get it sitting perfectly true with the centerline. If your tailstock has angular misalignment, it will introduce side cutting force when advancing the tailstock quill.

I pre-bore the chamber with the end of the bore being the same angle as the cartridge shoulder.