milling vise rotary base

[old martParticipant @oldmart]

[old martParticipant @oldmart]

Just to really wind up the haters of milling vise rotary bases, we have been modifying one of the Bison 100mm vise bases. The object was to set one of the 100mm's on its rotary base and make keys for it to fit the Tom Senior and the drill mill. Mike made the keys, four as they have to fit different width slots in the two mills. The base was lined up with the vise and clamped up and I tried the keys as made to find what the error was. It was only 0.004" across the entire width of the jaws. I had thoughts od pinning the zero position and found there was room to have a 1/4" pin. So I slackened off the bolts holding the halves together and adjusted for zero tir across the jaws and retightened. The alignment marks for the degrees had not noticably moved, so I drilled a 6mm hole and used a 0.2498" solid carbide machine reamer so that an aircraft bolt with a ground shank of 0.249" fitted. The pin holds the alignment within +0 -0.0005" across the 100mm jaw width. I then fitted the second set of keys and tried the alignment on the other mill and to my surprise it was exactly the same. No extra fettling needed.

 I also looked at the 5" ARC versatile vise and base with a view to pinning it, but there is not really enough thickness of metal. So I cut off the lip at the rear of the casting instead to allow an extra 1/2" of Y travel when it is fitted to either mill.

 

 

Edited By old mart on 23/04/2022 19:02:55

Edited By old mart on 23/04/2022 19:09:50

[SteviegtrParticipant @steviegtr]

Great job Old mart. I did look at one of those Vises before choosing the one i did. I guess there are times when you want to tilt at a certain angle.

The one i bought had an error in the Key slots under the vise. So i took a smidge off one key & now it's all good on the Senior.

Steve.

[old martParticipant @oldmart]

Rotary bases are things that are rarely needed, spending most of their lives in a cupboard, but they can be well worth having occasionally. We have at the museum a large rotary and tilting device which originally held an 8 inch rotating top like the top of a rotary table. We have used it in the drill mill, but it is much too heavy for the Tom Senior, the top is modified to take one of those Bison 100mm vises or a 6" four jaw independent chuck. It has been used once this year, but I can barely lift it, and it takes up about 10" of Z height before the vise is fitted. That has a pin to set the tilt horizontal when not in use, that is where I got the inspiration for the rotary vise base.

We have 2 of the Bison 100mm vises at the museum, the original came with the drill mill and the one in the pictures was NOS with the base which I was very lucky to pick up on ebay for around £100. They are keyed for both mills to be used as a pair if needed. The only shortcomings of this style of vise is the limited opening, only about 80mm and the jaw lift which cannot be eliminated, even by devious means, I have tried with limited success.

Edited By old mart on 24/04/2022 15:56:32

[Mark RandParticipant @markrand96270]

When I rebuild the Beaver mill I didn't bother scraping the sheears of the T slots, so I don't trust them to be absolutely in line with the X axis. Thus, I always indicate the fixed jaw of the vice in whenever I put a vice on the machine. I'm not convinced that a dowel would give me any useful improvement when using a vice with the rotary base.

[old martParticipant @oldmart]

The mill drill tee slot which was appropriate for the 100mm Bison vises had a 0.007" error from one end to the other. It has a 500mm stroke, so the length is more and because it has a round column I was able to mill the entire rear sheer if that slot in three stages by swinging the head. The error along the entire length of that sheer is about 0.0005" from end to end. It helps when both Bison vises are used together for a long workpiece. I haven't bothered to check the other three slots for runout.

[Author]

Posts