Vise squareness question

[ZombiWelder]

Gentlemen!
I bought this precision vise from shars company, to replace cheap Chinese vise I had before. https://www.shars.com/products/workholding/vise/4-single-lock-down-precision-milling-machine-vise
The Jaws out of the box were not square to the base, despite spec being . 0004 "
Checked with several starrett tools. I sent pictures to the Shars and they responded that's the way the make em..... My Chinese vise was off about the same way.
What do I need to do to get a vise that's actually square and I can mill soft materials square.
Thanks a bunch.!
Arthur

 

[Technical Ted]

Gentlemen!
I bought this precision vise from shars company, to replace cheap Chinese vise I had before. https://www.shars.com/products/workholding/vise/4-single-lock-down-precision-milling-machine-vise
The Jaws out of the box were not square to the base, despite spec being . 0004 "
Checked with several starrett tools. I sent pictures to the Shars and they responded that's the way the make em..... My Chinese vise was off about the same way.
What do I need to do to get a vise that's actually square and I can mill soft materials square.
Thanks a bunch.!
Arthur

Have you tried removing the jaw and stoning both the back side of it and the main jaw? There may be a burr in there someplace. Also, check that the removable jaw is flat and both sides are parallel with each other. A surface plate would help here.

If you want to try and fix it yourself (since Shars seems to be no help) I would check that the flat base was parrallel with the vise bottom. If it is, make sure your table is stoned flat. Then, you could take an end mill and true up the vertical base making sure you indicate it in the X axis first if it's keyed on the bottom of the base).

Anyways, that's what I would do if I was going to try and fix it.

Ted

 

[ttabbal]

You show the movable jaw being off with the square. Is the fixed jaw that way too? That's the important one, though I think their argument is bogus. I would think that slight angle would make it more likely that a part would come loose. Perhaps not a LOT more likely, but somewhat. I might be off base, but it seems to me you have a couple options.

Mill the jaws square or make some square soft jaws. In my view, it should not be necessary, but it's an option. And they would be as square as your machine is. Ted's post covers some options for fixing it, I'm less useful there.

Buy a better vise. Certainly more expensive, and to get a known good brand like Kurt or Glacern you're going to be spending a lot more than that. Perhaps a used older style like the Bridgeport branded units. There was a recent thread about an inexpensive ebay vise they liked, I believe it was about $85. You might ask them for a squareness test.

 

[Mitch Alsup]

I had to disassemble my chinese vise and clean the living snot out of all the machined surfaces for it to be anywhere close to square.
But after doing so, it is pretty square.

 

[macardoso]

I own that exact vise and it works wonders for me. As stated above, disassemble the vise and check for burrs. Stone if necessary. There is a center setscrew in the back of the moving jaw, once assembled (make sure the half ball inside the moving jaw is correctly sitting in its cup, grease helps here), snug up on the center screw until the vise screw is slightly stiff to spin. This will remove all the play in the jaw.

Shars service has been good to me in the past. Its possible you got a bad vise and perhaps another wouldn't have the same problem.

Edit: I'm pretty sure the guy from Shars has no idea what he is talking about. There is a angle lock feature to the jaw to prevent the jaws from rocking when closed, but it has nothing to do with the squareness you are talking about.

 

[higgite]

I wouldn't be too harsh on Shars. It's my understanding that some mill vises are made that way on purpose. The vise will flex when tightened so they tilt the stationary jaw slightly inward to compensate for the flex when you lock in a work piece. The way you have the work piece mounted with the ball bearing would negate any tilt the movable jaw might have. If you aren't getting square corners when you face mill, it could well be that your mill isn't perfectly trammed. Not saying that is isn't, just offering a possibility.

Also, the .0004" accuracy that Shars claims has nothing to do with the jaws. That spec is the side to bottom squareness, or how close the sides are to being at a right angle to the bottom of the vise, in case you need to turn it on it's side for a milling operation.

Tom

Edit: FWIW, here's a video on vise flex.

 

[mattthemuppet2]

unless you spend $250-300+ on the higher end import vises (eg. the 550V line Shars offers) then these vises are a kit. I bought the non-CNC version that you have - took it to pieces, stoned all the surfaces, drilled and tapped the fixed jaw for longer bolts (and bought better quality bolts), smoothed out the lock down mechanism (it was a rough cast surface), added shims where necessary and now it's a nice vise. The fixed jaw does flex upwards slightly, especially when holding thin work on parallels, so I have to tap down the work, but the lockdown mechanism otherwise works very well. I haven't checked out all the surfaces with an indicator, but the bed was parallel to the table and the jaws close without a gap anywhere, so I'm happy. For the money it was a steal.

 

[pacifica]

Depends on how much time you want to spend on truing up a vise. I bought used Kurts(6" and 8"), and don't see those problems and can rely on the castings not to break. Sometimes I crank on the 8" with a 24" extension which puts a lot of strain on the vise.

 

[benmychree]

I would question the precision of the tools that you are using to quantify the (supposed) out of squareness; none of them are made for the purpose.

 

[ttabbal]

Depends on how much time you want to spend on truing up a vise. I bought used Kurts(6" and 8"), and don't see those problems and can rely on the castings not to break. Sometimes I crank on the 8" with a 24" extension which puts a lot of strain on the vise.

I know it's a bit off topic, but why? The provided handle should provide pressure in the tons. Using a longer bar seems more than a bit extreme. But I am also a noob, so perhaps I can learn something.