Wilton 9400 Vise- Jaw alignment

[the spyder]

i picked up a 4" Wilton 9400 vise a few months back from a CL seller. It came from a local University's welding shop. It was in decent shape, but badly needed new jaws and a fresh coat of paint. I ordered jaws from wiltonviseparts.com and while I waited, I started refinishing the body. Everything looked to be in good shape and I found the date code of 12-05-63 on the guide bar. Now, when I first reassembled the vise, using the old jaws, something was off. The jaws did not close evenly. I chalked it up to the terrible condition the jaws were in and patiently waited for my new jaws. When they got here, I was incredibly disappointed to find the problem was worse with the new jaws. The jaws are great, but I've got no idea what's causing the jaws to be this misaligned. Has anyone seen this before? I'm going to take it to a machinist friend to take a look at. I'm tempted to just machine the jaw seats, but that won't fix the side-to-side alignment.

 

[zkling]

What does the key and way look like? Did you check the location of the mounting holes for the dynamic jaw holes? Looks like you have problems in two planes. Are th tops of the jaws coplaner?

 

[KMScott]

I had the same problem with my 600S, I had to adjust the key in the dynamic jaw support. I decided to weld a bead on one side of the keyway and remove material on the other side. The hardest part is figuring out how far to rotate it. this 600S was out exactly 1 degree. I would suggest pulling the key way out and assemble the dynamic jaw support and see if the jaws will align up without the keyway. If so then grab your machinist friend and get his help. Good Luck.

 

[Kevin54]

It looks like the vise has been sprung some by clamping things WAY too tight on the right hand side of the jaws. If you have a buddy that is a machinist, have him remachine the area where the jaws seat in. You have to do this with the jaws removed, and pressure put on the vise in the closed position. Remove the very minimum from each side. Then bolt in the jaws, close the vise, and see how much needs to be taken off of the end(s) of the jaw(s) to bring them back to even with one another. It's a simple fix if one knows what they are doing. If you weren't so far away, I could fix you up in no time.

 

[spongerich]

The dynamic jaw is pinned onto the slide. I've seen a few of the larger ones with the jaw skewed like yours. Clamp the slide in another vise (use some soft jaws) and see if you can rock the jaw side to side at all. Even if the pins are broken, it's usually a tight press fit so you might need to wail on it with a lead hammer. If you can get it straight, just re-pin it with a couple of taper pins. You could try to find the old ones and knock or drill them out, but if you can't, just drill and ream a couple of holes for some new ones. A 3/16" taper pin should be plenty large enough.

 

[Fretters]

Most of that disparity seems to be just the inserts, not the jaws themselves?

 

[ganymede]

Add me to the ' mis-aligned Wilton club'.
Mine was like the op's and out almost 3/16"!
Funny thing the top was almost perfect.
I put a hunk of 2 by 4 against the movable jaw and walloped it with a bfh...
no change. So I got my big ******* files and started filing. Took a bit off each side until they were almost even. There's now less than 1/16" and I'm fine with it.

 

[paulsomlo]

I had the same problem with my 600S, I had to adjust the key in the dynamic jaw support. I decided to weld a bead on one side of the keyway and remove material on the other side. The hardest part is figuring out how far to rotate it. this 600S was out exactly 1 degree. I would suggest pulling the key way out and assemble the dynamic jaw support and see if the jaws will align up without the keyway. If so then grab your machinist friend and get his help. Good Luck.

Kevin - how did you figure out how much to offset the key?

 

[Maui]

Kevin - how did you figure out how much to offset the key?

Probably trial and error.

 

[KMScott]

Kevin - how did you figure out how much to offset the key?

I could have used trig but instead I drew it up on Acad including the key way and rotated the Dynamic till it aligned. This gave me the offset amount I needed to do on the keyway. It actually came out to 1 degree almost exactly.

 

[paulsomlo]

Finally tackled this - I went ahead and made a whole new key. I calculated the amount of offset by clamping a thick, rigid straight edge to the rear jaw cheek and measuring the amount that the dynamic jaw cheek was offset using feeler gages. I measured the distance from where I placed my feeler gages to the center of the dynamic tube. S=rθ gives the angle of rotation given the distance (r) from the center of the dynamic tube, substituting the feeler gage measurement for "S". The offset needed for the key is just the ratio of "r" to the distance from the center of the dynamic tube to the key. This works, because for small angles, the straight line between the ends of an arc (chord) is very close to the length of the arc (S). In my case, the offset was about 0.028". Things line up nicely now, not perfect, but very close.