Experimenting with slotting tubing for dropouts on Sheldon Horizontal Mill. Vise allows pass through for stays and keeps various diameters centered on slotting saw. For tapered tubes the vise can be tilted to compensate and a round wire on the top of vee block makes for rigid setup.
Sputnik main tube fixture on the old horizontal mill.
Sputnik Chainstay Fixture on M22 Diamond Mill.
Another view of slotting setup. Cut a bunch of straight 4130 to dial it in. 