Summer project - new mill

I picked up this little knee mill last spring, and have spent the summer rebuilding it. As near as I can determine, it's a 1984 Enco 6x26 vertical knee mill, made in Taiwan. The overhaul  consisted of a full disassembly, replacing every bearing, many of the bolts and nuts, turning a 6" riser block to raise the head and installing an Arduino-based TouchDRO digital readout. It weighs about 600lbs (I brought it home in my Subaru!) and has a 1.5hp reversible motor that'll run at 120 or 240. (That's true 1.5hp, it pulls 18 amps on 120V.) There's still some work to do, but it's operational now. It's a great match in size and functionality for my 9" South Bend lathe. More to come...

Lathe DRO Installation

Finally decided to add a DRO to the old South Bend Lathe. When looking for info on how to add digital scales to a '40s era lathe, I didn't find much, so I thought I'd share what I came up with. The inexpensive digital scales I chose are not terribly accurate, but they're good enough for the majority of the work I do. 

The X axis was fairly straightforward: there's room on the back of the lathe to hang the scale. The Y axis was more challenging: tight clearances on the carriage led to mounting the crossfeed scale behind the carriage. Fortunately, on this SB with the rear-mounted countershaft/motor assembly there was room behind the lathe. 

 

Cheap but decent digital scales

Aluminum angle bolted to the tapped holes for the taper
attachment I don't own.

1/8" aluminum  extension bolted to the crossfeed carriage. The side
of the crossfeed casting was milled flat and holes were tapped
in the cast iron.

X axis hanger clamped to the rear ways.

X axis scale attached to y axis aluminum angle

Tripod head adapter

This is an adapter for a ball-head tripod for use with a spotting scope. A ball head works great for a camera, but not so great with a spotting scope -- it's tough to aim a scope when you loosen the ball and everything gets all floppy. This adapter adds a vertical plane tilt mechanism to the top of the ball head. Just lock the ball tight and use the tripod's pan (rotation) and this adapter for the vertical.This setup allows me to have both options -- a pan/tilt for the scope and a ball head for a camera, without carrying a bunch of gear. Plus, the pan mechanism that came with the tripod on the ball head is amazingly smooth, so I get to use that with both heads.

It has an Arca type dovetail quick-release plate on the bottom that attaches to the ball head on the tripod, and a clamp on top to attach to the scope.

 

The center pivot block is solid acetal plastic, or Delrin and the rest is aluminum. The acetal against aluminum provides a silky smooth motion.

The clamp and plates are compatible with the tripod hardware. The springs fit into holes on either side of the screw and parallel to it to keep the clamp open when not tightened.

The plate on the left goes on the bottom and is relieved to fit a locking pin in the tripod head's clamp. The one on the right fits on the scope and attaches to the top.

It works great. Smooth tilt, easy to use. I can pop the whole scope / adapter assembly off and use the ball head with a camera.

And here's the tripod with the scope and top assembly removed, and a camera on the ball head. It works very well and only takes a few seconds to switch.

When I started I figured I could find some standard dimensions for Arca Swiss type dovetail quick-release clamp and plate. I didn't have much luck, so I'll share what I came up with. These are what I used, but I had to tweak the clamp side a bit to make it fit. They should be a good starting point, but use them at your own risk. I have no idea if the Promaster tripod they were based on is a standard size.

I used a couple of 3/32" drills to measure the dovetails (actually .094" dia)

The clamp side dovetail needed to be cut more than shown here to fit the plate.