I've had a chunk of cast iron put aside for over a year so I can make a DTI mount for my South Bend lathe. I found the magnetic indicator was shifting in use, which negates the utility. So I decided to wing it and just carve one out. I didn't use anything more precise in this job than a Sharpie and my eyeballs for layout, although having a 45 degree angle gage helped when setting the piece for the vee groove.
Milling the saw cuts flat.
Roughing it out.
Milling the 90 degree vee.
Milling the far end for relief from the ways.
Milling out a bit more.
Drilling for the clamping bolt.
Transferring the bolt hole to a clamp plate.
Tapping the plate.
Hole for the indicator laid out.
Reaming to 3/8"
Tapping for the indicator lock screw.
Drilling out the end of a #10 screw.
A small piece of brass was pressed in and faced off.
I lifted the magnetic base indicator off the lathe and it fell apart...I guess this was the cause of the slop. I can't believe it was just pressed together...
Match drilling the plate and stop.
A dowel pin pressed into the hole to keep the clamp plate aligned. The clamp plate hole was drilled slightly larger.
I sanded and deburred all the surfaces and edges. About an hour and a half of relaxing and imprecise machining. It locks up rock solid. Little accessories like this pay for themselves the first time you use them.