# Dual milling vise alignment project



## John Conroy (Dec 15, 2020)

I did some work a few weeks ago that would have been much easier if I had 2 milling vises on the mill table. Of course that would require the vises to be perfectly aligned in both the vertical and horizontal plane. You can order 2 vises from major suppliers like Kurt and specify a matched pair and they will be delivered with equal bed height within .0005"
I was hoping to come close to that spec with this project but with only 1 Kurt vise and my orphan Chinese vise that has been sitting in a corner unused for 3 years since I got the Kurt.
After a lot of measuring in different ways I determined that the old vise is .074" lower than the new one but because they are similar in design they are pretty close (within .030") in alignment of the fixed jaw. The Kurt vise has keys that fit into the mill table slots and bring it to within .001" of perfect alignment every time so I hoped to make some offset keys for the old vise to get the rear jaw close to aligning with the Kurt. After some research on what I could use for a shim to bring the bed of the old vise up by .074" I found that 14 gauge sheet steel is .074" thick. I went down to Metal supermarket and looked in their drops bin for a partial sheet but had no luck. I asked the counter guy how much they would charge to supply a 9" by 12" piece of 14 gauge sheet steel. He quoted me $5.38. Yes, that's right five bucks!! They had it ready for me in 20 minutes.





I scribed the shape of the vise onto the sheet and used a sketchy set up in the mill to hold the sheet metal in place while I carved the shape out freehand.













I did one end then flipped the sheet in the vise and did the other. It turned out pretty well I think.













I made some small bridge pieces to fit into the key slots on the vise to prevent bending and then made the keys with .030" offset and screwed the shim to the bottom of the vise.













It turned better than hoped, not up to the .0005" figure given by Kurt but good enough for my needs. I made 2 short videos showing measuring the alignment. You can see that most of the inaccuracy is in the old vise not being flat or straight.


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