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Milling vise jaw lift?

I usually smack the metal piece down with a compo dead blow hammer. Another way is to put a round piece of drill rod horizontally between the workpiece and the sliding jaw. The drill rod rolls upward as the jaw rises.

Sometimes it takes more than 1 blow to reseat the work-piece. Sometimes,I tighten reasonably,smack the piece down,and finish tightening,with another smack.
 
Man, this has been discussed many times lately. Check to be sure the fixed jaw is perpendicular to the table first then check the flat between the jaws to be sure it is parallel to the table. Then check the movable jaw to see if it is perpendicular to the table. If they are ok then the next step is to put the work on the parallels and put some round stock against the work on the movable jaw side and clamp the work by hand. Then lightly tap the work down onto the parallels as you tighten the jaw by hand.

If the sides of the work against the jaws are parallel to the top and bottom of the work it should lay on the parallels. If the sides are irregular then you will have to come up with a different way to hold it in the vise.

A mill vise does not hold a parallelagram flat on parallels.
 
Look on the back side of the moving jaw. If it is not too old of a vise, there may be an adjustment screw there. I have taken a couple of vises apart at work, cleaned them up and snugged up that screw. The vises worked much better.
 
jaw lift

I don't know if there is a solution when trying to hold thin material near the top of the jaws on a poorly manufactured vice. I know pounding on it with a large mallet will not help although it can be a good stress reliever. The only solution that I can think of is get a better vise or perhaps make up a small fixture to hold your part instead.
Simon
 
OK fellows
How do U handle lift on your milling vise Jaw?

If the job requires a part with a high flatness tolerance, I NEVER use a vise where the spindle is under the jaws. It will lift, even with the nicer Kurt 3600V or PT400.

I've never tried one, but the Gerardi vises look like they'll do better since the spindle is much higher.

I have some specialized fixtures that clamp with OK-vises, and it will hold a flatness tolerance that you won't believe...the part will not lift. On the other hand, it is a specialized fixture, so there is very little clamping range.
 
Ok fellows I want to thank u all for your helping hand!
But I believe I`ve figure out the problem.
My vise is a D-675 and I took off the moveable jaw and found the half ball segment was missing! So a call to Kurt Monday and get a new one ordered.
Has to make it better then it is!
Jim
 
I've got to replace my 6" Chicom aftermarket vise. It lifts the work clear of the parallels and cocks it several thousandths of an inch. There's no adjustment, so out it goes. I've struggled with it long enough.

I'm considering buying a new 6" Kurt from one of the internet sellers. Are there any other brands that are as good?
 
Can only speak for Kurt vises because that's all I've used.

If your part is lifting, your part isn't square enough to hold in a vise. Give yourself something decent to hold onto and you'll never have a problem.
 
I Don't know if this is OK to do but it works fine for me .
On my Hendey shaper the vises tend to lief parts up off the parallels. What i have been doing is moving the clapper over the part and tightening down on the clapper on the part and than tightening the jaws. It works great!!
mac,,,
 
There are a couple of ways I will hold a part that must be absolutely flat to the table or vise bed.

Instead of a vise I will use a couple of "toe dog" clamps. I have several sizes. If you have never seen them each looks like a movable vice jaw. You bring them up touching the work and clamp down to the mill table with a "T" bolt and nut. Each clamp has a square or Allen head bolt that moves the jaw in and down. As it tightens it move down also.

If the part is to be held in a vise only I use a tool called a "hold down" not sure if that's the real name but it's what they were called in ever shop I worked. These are hardened steel the looks like a parallel from above but wedge shaped when viewed on end. The sharp side goes against the part and the flat against the jaw. When the vise is tightened the "hold down" pushes in and down at the same time.

I have the above tools and used them all the time but cannot locate a photo on the web or even find them in any of my catalogs. Does anyone have another name for these tools?

Walter A.
 
Walter, you have the name right, they are called hold downs. Here is a link to Starrett's version: it's the second item on the page.

http://www.starrett.com/download/330_p435_438.pdf

Thanks, you never know if the name of the tool you have used since apprentice days is valid in other areas. This link helped.

I rarely see the tool used anymore. Any of my new machinists have to get educated each time I see them hammering away at a part in one of the machine vises.

My rule is if you want to cut square to the side clamp it in the vise with a dowel against the movable jaw. If you want it parallel to the bottom use a "hold down" or the surface grinder instead.

Walter A.
 
Can only speak for Kurt vises because that's all I've used.

If your part is lifting, your part isn't square enough to hold in a vise. Give yourself something decent to hold onto and you'll never have a problem.

I only wish that were the case. It does the same thing with a square 5/8" lathe tool. I'm going to buy a Kurt vise next week and use the old one for a door stop.
 
How exactly do the vice hold downs work? I cannot seem to visualize it. Do you set them up like parallels?


Thanks, Steve
 
Bein retired,still have a set of above mentioned tools from apprentice days,we called em shaper hold downs in this neck of the woods,and the shaper dept, is where I learned aboot em.
Gw
 
How exactly do the vice hold downs work? I cannot seem to visualize it. Do you set them up like parallels?


Thanks, Steve
Instead of the vise jaws contacting the part the hold downs are between the jaws and the part. Use parallels up against the jaws to keep the hold down at the top edge of the jaw. The narrow edge to the work and the wide edge to the vise jaw.

When you tighten the vise the hold downs tighten in and down.

Walter A.
 








 
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