Drewed Posted May 22, 2011 Share Posted May 22, 2011 My post vice has been repaired. It looks like the movable leg has been welded back on. The problem is that the jaws are no longer parallel. I read that this could this be caused by the spring. Can this be the case ans a simple spring replacement my solve this issue? Or is it more likly that the leg was welded out of true and I'll have to cut it off and re-weld it? Quote Link to comment Share on other sites More sharing options...
Timothy Miller Posted May 22, 2011 Share Posted May 22, 2011 We need to see pictures to give you useful information. The spring would not affect the alignment of the jaws. Are the jaws out of parallel on the horizontal plane or vertical plane. If it is on the horizontal it is the hinge that is tweaked. The normal fix is to heat up the hinge and bring it back into alignment no welding required. If the jaws are out of alignment on the vertical plane one of the legs is bent and will need to be straitened. The jaws were never meant to be parallel on the top to bottom because the moveable leg closes on an arc and the the jaws will only be parallel through a short section of this. I hope this helps. Quote Link to comment Share on other sites More sharing options...
bigfootnampa Posted May 22, 2011 Share Posted May 22, 2011 I agree with what southshoresmith said... also note that one of the useful features of the post vises is their flexibility, allowing you to clamp a slightly tapering workpiece solidly and without damage to the work or the vise. The legs can twist a little as you tighten the vise allowing for a good grip on non-parallel work shapes. This is normal and good! Quote Link to comment Share on other sites More sharing options...
Bob S Posted May 22, 2011 Share Posted May 22, 2011 I have 'squared up' vises by using shims cut from coke cans. Just decide which way you have to go and slide in a shim or two down on the hinge. It doesn't take much unless your vise was in a wreck. These vises were (in my experience) pretty rough forgings. I guess they figured the blacksmith could make it work. Bob Quote Link to comment Share on other sites More sharing options...
clinton Posted May 23, 2011 Share Posted May 23, 2011 If it is a horizontal problem you can draw out the shorter leg or upset the longer to realign, drawing out is easier of course. If it less than 1/4 inch I would just leave it alone Quote Link to comment Share on other sites More sharing options...
pkrankow Posted May 23, 2011 Share Posted May 23, 2011 My vise jaws meet one end about 1/2 inch before the other (twist) 1/2 inch offset side to side and 1/8 inch offset up and down. Works good. I can grab something lightly, fiddle with it, then tighten it square and pop a spacer in the other end of the jaw nice and easy to deal with the twist. The offsets don't bother me. Phil Quote Link to comment Share on other sites More sharing options...
Drewed Posted May 23, 2011 Author Share Posted May 23, 2011 I'll have to get pictures later as there is a heck of a storm going on now. The left side of the jaws close well before the right side. No amount of cranking on it will close up the right side. I'll give the hinge plates a good looking at. Quote Link to comment Share on other sites More sharing options...
ThomasPowers Posted May 23, 2011 Share Posted May 23, 2011 Most likely the shaft has been twisted by someone really cranking down on a piece in the jaws on one end and not using a space in the other. (as the screw is in the middle having work only on one side means the screw will twist the jaws if you crank down on it.) I would suggest heating a section of the leg (where it's smallest) and twisting it back to parallel. With some fast help you could probably even use the vise to twist itself back straight once the leg is hot: if you vise will fit crosswise in the forge with the leg in the hot spot, heat to a good red and stand the vise up and close it till the jaws meet (may need a shim on the close side to deal with any spring back. Problems with side to side alignment are shim or heat and tweak the cheeks of the joint the moving legs rides in. Vertical mis-match means an abused vise. Sometimes the leg is bowed and can be straightened. I did take one and hot shrunk and riveted a plug in the original warllered out hole and then re-drilled it to deal with the offset. Making a set of vise jaw covers with one a tad thicker is probably easier. Now all you folks with *nice* vises---go make a set of spacers to use in the side opposite of your work piece! For most standard sizes just take a 3" piece of square stock and saw or hot cut down from the end 1" and bend the flaps over to fit the top of the vise jaw curve and *stamp* the size on the flap. For smaller thicknesses you can clamp it in the vise and spiral the material around to make a "head" though 1/4" is generally the smallest I need. Quote Link to comment Share on other sites More sharing options...
Drewed Posted May 24, 2011 Author Share Posted May 24, 2011 Pictures! Here is a shot of the weld Left side ( close side ) I see that they are not parallel top to bottom as well, not so concerned about that. Right side This is the big problem. And no, they don't straighten when cranked down Something is definitely twisted. The file is flat against the back leg and you can see how far off the front leg. Quote Link to comment Share on other sites More sharing options...
Timothy Miller Posted May 24, 2011 Share Posted May 24, 2011 Throw it in the forge and twist it back. You need a big bar to slide threw the eye and another vise to clamp it in or you could clamp it to a very solid bench. You could also put it back in place wile its hot and just gently close the jaws till they align. It you have a torch you can use that too. Leave the weld alone welds can crack when heated and subjected to stress in my experience. Tim Quote Link to comment Share on other sites More sharing options...
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