Self centering mill vise

[KYCaster]

I need a project for machine shop class. I may as well build something I may have a use for down the road.

I know a couple of you guys have built these, can you tell me where I can find plans or drawings? That would make it a whole lot simpler than starting with just an idea.

Thanks for any help you can give me.

Jerry

P.S. This is not a beginners class. One of the recommended projects is a tilting vise, so a self centering vise will fit the requirements.

[Marvin S]

I cant help with drawings but I do have two factory made ones and could take some pictures if you want.

[lup]

I'd like the pictures even if he doesn't want them. That sounds neat.

[KYCaster]

I cant help with drawings but I do have two factory made ones and could take some pictures if you want.

That would be great.

Thanks a bunch.
Jerry

[Marvin S]

If I dont post them by next Wednesday PM me as I probalby forgot. Monday is a federal holliday.

[HotGuns]

How about a half scale Kurt Angle Lock vise?
I made one just for small stuff that got swallowed up in the full scale version.

[Chicken Thief]

Have a lathe and a mill (both mini) and have used cutting machinery for the past 30yrs+, but let ne say that that is pure eye candy on the border to pord.
Man i wish i had the tranining/ability to do something like that

[ShootR]

That is some skill!

[Marvin S]

That looks to be a very nice vise you have there. Here are some pics of a Wilton self centering vise. The jaws ride on the bed and dove tails as you can see in the pics. There is a gib type wear strip on one side to take up wear. Of course you will need a left and right hand thread for each jaw. The ends of the main screw are supported by cap plates as you can also see. It would have done no good to take the swivel base off as its solid under the vise bed. it is a 4"X4" vise. Hope this helps some.

[KYCaster]

Thanks Marvin. That gives me a good place to start. It looks pretty simple compared to some others I've seen.

Jerry

[badgeredd]

How about a half scale Kurt Angle Lock vise?
I made one just for small stuff that got swallowed up in the full scale version.

That is a fine piece of craftmanship. Be proud of it, I would be.

Edd

[Lefty SRH]

Thats a very nice vise HotGuns! A smaller vise definately has its place in the machine shop.

[Buckshot]

...........Marvin, how repeatable is that double acting vise?

..............Buckshot

[Marvin S]

I have not really used it very much to give an honest answer to repeatability. I'll try to check it out and let you. Might check some some various thickness parallel bars with a dail test indicator in the mill spindle.

[KYCaster]

Marvin, thanks again for the pics. I got approval from the perfessor to use this for my major project for the semester. He was reluctant to begin with, but after seeing your pics he's now pretty enthusiastic about it.

One detail I can't see in the pics is the gib. Seems to me it has to be captured by the adjustment screws, otherwise it would slide up the dovetail, eventually bottom out and put pressure up on the jaws as well as to the right. Can you tell me how that works?

Buckshot, assuming the dovetails are accurate, I think the repeatability depends entirely on the fit of the screw to the jaws and the end plates.

With minimal slack in the threads, the end shake of the screw between the end plates will control the repeatability of the center point. Since there's no thrust on the end of the screw as there is on a vise with one moveable jaw then the end shake can be controlled with shim washers at the end plates without fear of compression or wear.

I'd like to get some input from you guys as this project progresses so I'll be posting some pics and asking lots of questions.

Jerry

[Marvin S]

I'll take a look at that and see what if anything captures it. No doubt some precision grinding would be in order on the sliding surfaces and threads cut on a good quality lathe without a drunken lead screw.

[snowshooze]

I built a self centering vise a while back. Worked great. It was a sprung vise for horn and antler stuff. Commercial customers, sold a couple of them.
But, it can easily be accomplshed with r/l threaded jaw screws as well.

[Marvin S]

I mounted it on my Bridgeport today and took three half inch thick parallel bars to test it with. First I just picked up the back edge of the bar with a Starrett last word indicator. I removed and reinstalled the bar several times and it went back to zero perfectly each time as long as you put the same handle pressure on it. Next I put a bar on each side of the first one and got the same results. It will vary maybe .001 if you don't clamp the parts with the same pressure each time. Maybe you would want to use a torque wrench? I was impressed with the repeatability of it.

Next I removed one of the adjustment screws for the wear adjustment. It does not attach to the strip in any way, at least the one I removed. It just had a radii on the end of the screw, and looking into the threaded hole with a flash light the wear strip was just flat. I would have figured it might have a socket for the ball of the screw. If I get some down time I might be able to take one apart as I have two of them.

[Buckshot]

I mounted it on my Bridgeport today and took three half inch thick parallel bars to test it with. First I just picked up the back edge of the bar with a Starrett last word indicator. I removed and reinstalled the bar several times and it went back to zero perfectly each time as long as you put the same handle pressure on it. Next I put a bar on each side of the first one and got the same results. It will vary maybe .001 if you don't clamp the parts with the same pressure each time. Maybe you would want to use a torque wrench? I was impressed with the repeatability of it.

Next I removed one of the adjustment screws for the wear adjustment. It does not attach to the strip in any way, at least the one I removed. It just had a radii on the end of the screw, and looking into the threaded hole with a flash light the wear strip was just flat. I would have figured it might have a socket for the ball of the screw. If I get some down time I might be able to take one apart as I have two of them.

.............Thanks Marvin. Main reason I asked is that if cherry cutting a cavity, opening the jaws once or twice to clear chips might be called for. So far as the gib is concerned, they normally do have a some sort of mating relief in them for the pressure screws to bear against.

..............Buckshot