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View Full Version : Can a Bport Vise be rebuilt.....



Bill in Ky
01-22-2009, 05:55 PM
As with most used Bridgeport vises with some age on them, mine lifts when tightened.
Anyone have a rebuild-repair for this?
Thanks in advance,
Bill

lane
01-22-2009, 07:20 PM
Never seen one that did not lift not even a new one. Thats why Kurt`s are so popular.
You can probably make it better though.

bob_s
01-22-2009, 07:20 PM
Usually the guide rails, which connect the moving jaw to the bed, wear and corrode. Modify them by either surface grinding to flat, or replace them with gibbed rails.

pcarpenter
01-22-2009, 07:31 PM
I bought the two main castings that someone was clearly "cleaning up". The base casting was fine and the movable jaw had been flycut square and fairly clean. I made new "anchor strips" (hate to call them gibs) from mild steel since I want them to wear before the base casting. I milled the flat and then surface ground them and it works pretty well. These, however, are not the lock-down style vise (think Kurt) and as someone already mentioned, will be subject to some jaw rise.

I bought a swivel base on Ebay from a guy and when it was the wrong item, some emails and a phone call ensued. The guy was great help and as it turns out he had worked at Bridgeport years ago. When they closed, he bought a bunch of vise castings at auction. He had some other parts too. I bought a lead screw and nut from him but he had few of those...not enough to finish off the vises. I mentioned to him that a standard thrust bearing could be made to work, which may be one of the other pieces you will need.

Anyhow, I basically have a "new" old vise now. It may not be ideal but I suppose there could come a time when a second vise may be handy. I have a Kurt for the other one and the heights are not the same, but for some things that won't matter and I could mount one on each end for work on long parts.

Good luck!
Paul

gellfex
01-22-2009, 10:15 PM
After many years of working with a BP vise, I recently got a Phase II "Kurt clone", and regret struggling all that time. Setups are MUCH easier. I read up about reconditioning BP vises before I bought the new one. Unless you really don't have the bucks and have the time, I say move on.

Carld
01-22-2009, 10:41 PM
Bill, pull the two bars that hold the moving jaw down. Are they worn? If so then make new ones and if the jaw still rises more than you want then pull the moving jaw off the vise. Measure the depth on each side and measure the vise one each side where the jaw is clamped on the base.

You may have to flycut or mill a few thousandths off each side where the bars are bolted to the jaw. That will take out some of the lift you describe.

Be carefull to not take to much off as the jaw will become hard to move.

oldtiffie
01-23-2009, 01:15 AM
My work is only "light" and I can hold my work down and counter the "up-lift" problem in the vice easily.

My main concerns are that:
- the base of the vise is flat;
- the top face of the "fixed" part of the vise - on which the job rests - is flat and accurately parallel to the vice base;
- the fixed jaw faces (vice and insert) are straight and vertical-
- the moving jaw is flat and close accurately on the fixed jaw-
- tops of both jaws as well as their inserts are accurately straight and parallel to the vice base.

I NEVER use a BFH or gain any mechanical advantage by using anything for extra leverage or force on the vise handle. The "ball" of my right hand makes an excellent "dead-blow" hammer.

Clamping directly to the mill table or over parallel strips is my preferred option over using a vise.

I see if I can use parallel strips (on the table) for height and just use the vice as a clamp.

Failing that I will use a Tool-makers Vise as it is self-clamping to the base and the accuracy is excellent.

I don't always get my preferences, but its surprising both how often I do and how well they work.

If, say, my moving vise jaw lifts, say 0.003", I loosen it, put a 0.003" shim right across the vice just in front of the fixed jaw, clamp/close the vise, "tap" the job down with a bronze "dolly" I have and -re-check.

It may work first time and sometimes it takes several tries and gets it done. It beats the hell out of having to buy a heavy "good" vise.

There is another very effective method that I posted sometime ago but it created a bit of consternation and indignation, so I deleted it. I may re-post it.

I am not, cannot and will not say that this is the way for anyone else, but it works for me.

macona
01-23-2009, 06:36 AM
Your jaw is only lifting .003? I wouldnt worry about that. Put a piece of round stock or a dowel pin between the moving jaw and the work. The jaw will lift, the pin will roll and the work will be pressed against the fixed jaw.

JoeFin
01-23-2009, 08:45 AM
I like my BP vise and I have a Kurt sitting next to it

I’ve reworked several vises by taking them apart, welding up any drill marks with nickel rod and running them through the surface grinder until flat and parallel. The “Rails” on the BP vise are better suited for restoration then most and can be remanufactured / reworked quite easily which makes them a good candidate.

As for the Kurt sitting next to it –

The jaw lift is less but it is still there as with all vises. It does seem however it takes considerably less blows with a dead blow hammer to seat the work in my BP vise. Possibly due to the increased jaw pressure of the Kurt. The Kurt is also faster, much easier to close / open, and square to the table

Basically if the vise is going to be sitting on the mill for a couple of weeks or months with coolant and chips all over it, I’ll use the BP and save the Kurt for the 1 off and Proto work

Scishopguy
01-23-2009, 03:52 PM
I think the biggest problem I have run into with the BP vises I have encountered is the fact that people tend to use a hammer on the handle to get that extra little bit of "umph," not realizing that the reason the part moves is that the rising jaw makes the jaws not be parrallel. By hammering on the handle, the user can spring the stationary jaw backwards. In extreme cases the stationary jaw can break off, as was shown in an earlier post someone sent in.

In the reconditioning process, be sure to check the stationary jaw pocket with a precision square. If it is sprung it can be fixed with a light cut. Then, as was suggested, use a piece of round stock between the work piece and the moveable jaw. You will be amazed at how well this works.