Kurt knock off lifting.

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LEEQ

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I got an enco kurt knock off. As I tighten it it lifts the work off of the moving jaw side parallel. I'm not sure how these work, so I'm not real sure what the problem is. Can anyone share some pics and a how it works? Once I understand the good one, I should be better able to diagnose and repair the cheapy. As it stands, the old Bridgeport vise is no worse than the new one.
 
In the moving jaw at the backside area, there should be a hole with a set screw in the center. Just tighten that set screw until you feel contact. After that, just tweak the tension on that screw until it minimize the lifting yet doesn't impede the rear jaw from moving.



Ray
 
That hasn't fixed it just yet. What does this adjust? I have a odd little widget between the pieces that I believe the set screw would bear on. Is there only supposed to be the one loose piece captured by the angled face of the piece that travels when you crank?
 
LEEQ said:
That hasn't fixed it just yet. What does this adjust? I have a odd little widget between the pieces that I believe the set screw would bear on. Is there only supposed to be the one loose piece captured by the angled face of the piece that travels when you crank?
Click to expand...

It depends... The Kurts and good knock-offs have a semi-circle ball in there. The screw presses against the flat side of the ball and the round part of the ball fits into a socket located in the angled piece. On the less expensive units, the screw just presses in angular fashion, against the angled piece. Either way, the screw just preloads the rear jaw and effectively puts downward force on the rear jaw and simultaneously puts upward force on the part that rides on the underside of the bed.

You might want to check if the main pressure screw (acme screw or big threaded shaft) is bent. That can cause all kinds of weirdness.

How much roughly is it lifting up?

Ray
 
I will measure lift, and check the screw out for straight. Thanks for your help guys. I am also going to see if thrust bearings are present or something I can add.
 
Thanks for the info. I just adjusted my vise and it works much nicer now. Just applied a little way oil after the adjustment and she's all nice and smooth a gain. I checked for lift by clamping a 1-2-3 block and sweeping it and I got less that .0005 movement. I think that is close enough for garage work :)
 
Reading Docsmachine's blurb,I can see that if he had put his time into making real money,instead of fiddling with that crappiest of vises,he could have bought a REAL vise with the money.

He did a nice job of making it accurate,but he still has a vise made of window weight grade cast iron,full of blow holes and who knows what else the Chinese tossed in(like old ball bearings,anyone?) Such HAVE been found in Chinese steel,breaking expensive tooling,and causing much trouble in commercial shops unlucky to have purchased Chinese steel. That vise casting will never have the strength and integrity of a decent Kurt. I got mine slightly used for $275.00,and have loved it. I did have to (luckily) find a JAPANESE swivel base for it,that is THICK ENOUGH to resist lifting from the table under milling pressure). My former ones were Enco's bought back in the 70's,and probably made in Taiwan at that time.(They would lift,too!) They worked o.k.. But,I'd HATE to have to rely on the new stuff coming out of mainland China.

Whenever you look at vises,look at the BASES to make sure they are thick enough to resist lifting under MODERATE milling pressure. Most are just TOO THIN. Look at a picture of a Kurt base carefully,and compare them to the vise you are considering. That is at least,a judgement you CAN start to make just by looking at pictures.

There are,at least,a few brands that cost MORE than chinese low grade junk,but LESS than a real Kurt. I advise buying one of those if you don't want to pay for a Kurt. They might still be Asian,but are a better grade. You get what you pay for. The Chinese can do good work,IF you pay them to do so. So can the Indians. No one can afford to do good work for starvation wages.
 
Well, I do see a Kurt in my future, just don't know how far off. Spending so much hobby time (that I have little of) fixing new Chinese crap is getting old. I like my Indian made rotary table/ dividing set. I like my Tormach and Bostar (Chinese) qctp's . Those tools took the least work and work well now.The other stuff is pretty buggy. My little Grizzly lathe purchased new included. As for what I have in the mean time, I dug into it a bit today and found it does have the half ball and it is stuck into the proper place with grease and tensioned. I don't know about lift or not as I put it to work clamping a slice of cold rolled for facing. It wound up parallel, but not square to the sides. I used a piece off copper wire between it and the moving jaw which allowed me to seat it down tight to the parallels. Without this, the unsquare sides tipped the whole piece as it was clamped. I can understand that. I'll probably use work arounds until I get stumped and have to get deeper into it. I wouldn't recommend buying one. I don't know about accuracy of grinding, but I do know it has weird pointed threads, not Acme. It seems to lack thrust bearings, and came to me with the half ball loose inside instead of sitting where it goes. The casting is thin and full of holes. It has been lifting on me too. Overall pretty crappy. I got what I paid for. I hate to buy used unseen, new Chinese was crap, unless someone can point me to a high quality knock off, I think my options are new high end stuff. The Glacern stuff seems on par price wise with Kurt. Guess I'll make that call when I can afford one.
 
I would like to thank LEEQ and John Hasler for starting this therad. I decided to finaly pull the vise on my mill appart this weekend. When I got it from work, the guys told me this was an import, but after I cleared off the grime is looks like it is actually a Kurt D60 :) It feelt kinda nice to get all of that old crud out of there. Before I was getting this rust colored goo on the ways but now I just have nice clean way oil. :)

LEEQ, as far as the threads on your vise go, It looks like mine are also sharp and not ACME. My vise does have the needle bearings in front which probably helps quite a bit when tighening the vise down. As for the rear jaw not being suare, maybe you could make an aluminum soft jaw and take a cut off of the face after you mount it on the vise. If you make two, you could also mill a step in for holding thnner parts without having to mess wit paralles. And since you did the cuts with your machine, they should be fairly accurate as well. I think I will try to make a set for myself at some point, just so I don't have to mess with parallels all the time :)

Good luck, and thanks again for inspiring me to do some overdue maintainace :)

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When you are ready to look for a Kurt vise, you might want to check out the Scratch-and-Dent section on the Kurt website. It looks like you can get a pretty good discount if you are willing to live with some pinhole porosity in the vise. They also have some more interesting items, like 400mm toombstones with a corner banged up... wonder how that happend :)
 
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