Prentiss Vise No. 19 teardown help!!

[toomanytoyzz]

I got this at an auction on Saturday, and decided to attempt to tear it down and give a molasses bath. I am having two problems with taking it apart. The first is how the hell do you get the lead screw removed from the dynamic jaw? It has some sort of lock washer inside with teeth. Looks like two of them are bent towards an indent which is on the lead screw to keep it from pulling out. I pryed on it, but was afraid I'd break or bend it. Anyone ??

The second pickle is the adjustable static jaw pin on top. How does it work, and how do you remove it? This thing is rusty to say the least. I submerged it in my molasses container before I left the shop. I'm hoping it will break loose some of the strong rust bonds that have occurred throughout the years.

Here's a couple of pics of it. Still deciding on a color or if I should leave it naked after wire wheeling.

 

[spongerich]

Sometimes the leadscrew is secured using a large split washer. You'd need to bend it to remove it. They're a PITA to remove and re-install. Could also be secured with a setscrew that's just invisible because it's hidden by rust/grease etc.

Removing the pin that locks the movable jaw can be very difficult. Sometimes you can pop them out by driving a couple of machinist wedges under them, but I've found that they're usually too stuck to do that without really buggering up the pin.

I've found that the easiest thing to do is to drill a small hole through the base of the vise right under the pin and then knock it out from the bottom with a long punch or piece of drill rod.

 

[madbasser]

The lead screw is held in by what should look like a crown nut with Two of the prongs bent in. To remove you will have to drill out the bent prongs and slide it out. If the crown nut does not have any more prongs I would not do it as those are impossible to find new.
Now the top pin is just slid in place but it might be rusted in really good. Let it soak and try to salvage it. Good luck and let the solutions do thier work. Give it time and it will pay off.

 

[hofferwood]

They look like this

And my suggestion---------Sore ****, sore ****!!

In other words---------if it aint broke--------Don't **** with it!!

Just clean around it.

Or you will represent my sig. line

Edit;

Oops I reread, the Pin

Mine was missing---Home made

 

[bigcaddy]

I got this at an auction on Saturday, and decided to attempt to tear it down and give a molasses bath. I am having two problems with taking it apart. The first is how the hell do you get the lead screw removed from the dynamic jaw? It has some sort of lock washer inside with teeth. Looks like two of them are bent towards an indent which is on the lead screw to keep it from pulling out. I pryed on it, but was afraid I'd break or bend it. Anyone ??

The second pickle is the adjustable static jaw pin on top. How does it work, and how do you remove it? This thing is rusty to say the least. I submerged it in my molasses container before I left the shop. I'm hoping it will break loose some of the strong rust bonds that have occurred throughout the years.

Here's a couple of pics of it. Still deciding on a color or if I should leave it naked after wire wheeling.

Your first pickle shouldn't be too bad as long as somebody else didn't already attempt to take the dynamic jaw apart.

Hofferwoods picture shows a nut that is pristine. If yours is in good shape, it can be reused. I took mine off with a scarfing chisel and bent the tabs up. One broke but the other survived. Do you cleanup and then reinstall the nut by hammering 2 new tabs downward. I decided to fab up a collar/set screw assembly since mine was on its last leg.

The pin is a huge pain in the *** so i can't help you there. I've pulled plenty of them out but used methods that might make members on here cringe and cry "vise abuse"

Good luck

 

[Outlawmws]

The pin is a simple taper and you may get lucky and have access from the bottom and can get a drift punch on it.

If not, then it's as BC mentioned, entertaining. Tap (not too hard) on the head sideways in opposite directions and try twisting. Once it starts moving, it should just about fall out.

The taper is tight for two reasons; The wedging effect, and if the surfaces are really ground, then it actually gets held in my the air pressure and the vacuum the attempt to pull them apart makes. I know it sounds weird, but if you don't believe me, get any cleanly ground taper fit and lightly oil it, then just slightly twist them together, and then try to pull them apart straight, without any twisting...

 

[toomanytoyzz]

They look like this






And my suggestion---------Sore ****, sore ****!!

In other words---------if it aint broke--------Don't **** with it!!

Just clean around it.

Or you will represent my sig. line

Edit;

Oops I reread, the Pin



Mine was missing---Home made

That's like looking at the underneath of my vise. I think I'm gonna take your advice. It's tight and the screw is pretty clean. I'm just going to let the molasses do its job and go from there.

The jaw pin may pose a little more of a challenge. I'm also going to let the molasses do its thing, but I have my doubts due to the excessive rust. One more question.....if this was a brand new vise how would you remove the pin? It doesn't appear to be any sort of marks on the pin which leads me to believe that it has never been removed.

 

[rusty65]

If it was new you could simply twist and pull the pin out like outlaw stated. Back when the vise was new it didn't have the super glue of time meaning rust and grit to interfere with the taper.

 

[toomanytoyzz]

The pin is a simple taper and you may get lucky and have access from the bottom and can get a drift punch on it.

If not, then it's as BC mentioned, entertaining. Tap (not too hard) on the head sideways in opposite directions and try twisting. Once it starts moving, it should just about fall out.

The taper is tight for two reasons; The wedging effect, and if the surfaces are really ground, then it actually gets held in my the air pressure and the vacuum the attempt to pull them apart makes. I know it sounds weird, but if you don't believe me, get any cleanly ground taper fit and lightly oil it, then just slightly twist them together, and then try to pull them apart straight, without any twisting...

I know exactly what you are talking about. It's almost like they are glued together.

Let's say all other methods fail to get them separated. What if I welded a small thick bolt to the end of the pin and used the socket to turn it loose? I would just cut it off and grind/polish it smooth once I popped it free.

I really appreciate the advice and pics guys!!

 

[Outlawmws]

I'd consider the welded nut, (you did mean nut, right?) as the last resort.

 

[toomanytoyzz]

I'd consider the welded nut, (you did mean nut, right?) as the last resort.

I use a nut when I don't care about the piece I'm trying to remove. Using a bolt (I'm talking about a bolt I cut less than an inch from the head) you can cut it off easier and clean it up as if it was never there.

Here's a couple of pics of the last batch I made (usually just cut a bolt but I was teaching a friend how to use a chop saw) to remove the windshield frame of a land cruiser I am restoring. The screws are flat and you don't want to weld it to the hinge .

 

[Outlawmws]

Got it! Still would do that last. I think it can come out.

 

[hofferwood]

If you do the welding gig---use a long hunk of "all-thread" and then do a slide-hammer type of action.
You will have better results than trying to "twist" it out. Think of a "Morse or Jacobs" taper--they don't twist.
By the way, the taper on those pins are unique, smack between a Morse and Jacob angle------it's a Prentiss angle

 

[KMScott]

By the way, the taper on those pins are unique, smack between a Morse and Jacob angle------it's a Prentiss angle

I have measured and fabricated a couple pins for the Prentiss swivel jaws. The pin angle is 3 degrees per side (mold maker talk) or 6 degrees included angle.

 

[hofferwood]

I have measured and fabricated a couple pins for the Prentiss swivel jaws. The pin angle is 3 degrees per side (mold maker talk) or 6 degrees included angle.

Yup, I couldn't remember, been a few years
Mine won't rust though

 

[Outlawmws]

Is it the same angle for a Reed pin? (I got some measurement's on a pin a while back and that seemed to calculate out to just above 3-1/4 deg... )