A milling machine stock positioning stop.
A 5 axis mill stop, a google image search shows other versions of this. It is used when putting stock in the vise to index for repeated operations. The old version is in background, cheap and effective but a PITA to adjust so I’ve been wanting something else. The new one uses one tool (vs 2) and has two screws (vs 3) and is faster to position and set. The “real” ones are $65-$100+ so that was an incentive for this project.
If you ride bicycles, the shaft should look familiar – it is basically a stem (the part that holds the handlebars), I even used some cut offs from frames past. Sure wish my welds weren’t so cobby. The ends are seamless stainless steel gas (Hydrogen) line and doesn’t like to be machined (plus welds are never fun to machine, lucky for me coated carbide tooling exists). After I welded one end, I realized the weld was going to interfere with the range of movement so I squished the other end.
The base is a puck from the cut off bin, the groove was cut on the mill with a boring head. I don’t have power feed on the quill and [the groove] being stopped, it was a real pain to cut. I was sloppy and just eyeballed the radius but got it close enough (welding warps the tubes so getting it right would be wrong). The tee nut takes a 1/2″ bolt which is five definitions of overkill for this so I made an adapter for a 1/4″ bolt. A drilled 3/4″ rod with a back bore ties it all together. Again, a good fit is an aesthetic thing but scrap is compelling.
The rod stack was made from bubble gum aluminum (the drawback to scrap yards) – really sticky stuff that needs super duper sharp tooling or it just sicks and tears. I used the same set up to mill the groove but since it was a through groove, it as cake.
The rod clamp washers were interesting – you want them to pinch the rod by the barest amount possible so they don’t tilt when screwed together. Took a couple of tries but I clamped the two washers together, drilled the rod hole and then faced one of the washers a couple of thou. Now there is just a wee bit of tilt when clamped and I don’t have to add meat to the other side (such as a set screw or shim).
I kinda like the knob; the outline was pretty much free hand with files, the grooves were eyeballed on the mill with a ball end mill. The knob was still part of the rod, laying on it’s side in the vise. Machine a groove, rotate, groove, repeat for nine grooves. If you look at the big image, you’ll see they aren’t spaced evenly and how torn they are, gumball AL. The only problem is the grooves aren’t as grippy as I had hoped so it might be difficult to tighten when my hands are slathered in oil.
I pressed on a little T hat on the rod, not sure it helps but it looks good.