Setting Up Something Square In The Mill Vise

[bborr01]

Why not open your vise and lay the workpiece down flat and side mill it to square it up? Also, in the first picture it looks like the parallel is too thick to close the vise on the workpiece and you have a very small piece clamping a larger block. I'd either get a narrower parallel and skip the small block or use a wider block wo it is clamping the whole width of the workpiece.

[JoeLee]

Why not open your vise and lay the workpiece down flat and side mill it to square it up? Also, in the first picture it looks like the parallel is too thick to close the vise on the workpiece and you have a very small piece clamping a larger block. I'd either get a narrower parallel and skip the small block or use a wider block wo it is clamping the whole width of the workpiece.

I've done that before. It works fine providing the vise is perfectly in line with the table travel and you have no play in the saddle.

The reason the small block is in front of the piece is so I can get the square in there. The base of the square is the same thickness as the part.

JL.................

[Arcane]

Joe,

Another idea when you have a thin workpiece is to use a combination square. You put the square head on the top of the vise jaws and the blade goes down into the vise plus upwards. This allows you to square up workpieces almost as thin as the blade. For thin workpieces this also makes it easier to hold the square head and workpiece while using gravity for the handle (as you mentioned).

This is only "fairly square", but sometimes that is all you need.

I was thinking of something similar a couple of days ago. I had the idea of getting a small machinist's square and cutting the end of the blade off so it could sit blade down on the top of the jaws and have clearance from the bottom. Like you say, only "fairly square", but it certainly would be sufficient for everything I need squared up.

[JoeLee]

Joe,

Another idea when you have a thin workpiece is to use a combination square. You put the square head on the top of the vise jaws and the blade goes down into the vise plus upwards. This allows you to square up workpieces almost as thin as the blade. For thin workpieces this also makes it easier to hold the square head and workpiece while using gravity for the handle (as you mentioned).

This is only "fairly square", but sometimes that is all you need.

I can try that. I have a Lufkin 6" combination square that is new and tight. I did grind the tops of the jaws several years ago so I know they are parallel. The bottom of the fixed jaw should be sitting on vise unless it moved when I tighten the screws on it. I can indicate along the top edge to find out.
I think my main problem is the slight jaw lift I have that may be causing some issue..... sometimes and that depends on the part. I really need to address that.
Just hoping that I don't have to cut the under side of the surface where the hold down plates ride.
Sometimes I'll place a 1/2" x 3" long dowel pin between the part and the movable jaw, but don't take heavy cuts.

So getting to the vise part....... what would be the best way to check for wear under the edges where the hold down plates slide. If I were to clean those up I would have to use large woodruff key cutter. I suppose the first step would be to grind the bottom edges of the movable jaw and the hold down plates and see how much jaw lift that eliminated and go from there. Anyone ever get into this before??

JL..............

[Paul Alciatore]

Actually, using Joe Pi's method does not depend on the vise being parallel to the table travel. That is the glory of it. By going around all four sides in the same direction of rotation, you eliminate the angle of the vise which could be 45° or any angle to the table travel and the block will still have those four sides and the top mutually square to each other and with opposite faces parallel. The head must be trammed square to the X and Y axis movements (which should also but not necessarily the same as the table top). But basically his method provides square and parallel to the limits of the machine as it is presently set-up.

But keep in mind that no mill is ever going to be perfect. This also applies to surface grinders.

Want to loose sleep? Unlock the gibs as they would be during milling operations. Mount a DI with it's tip about 5" or 10" off the spindle axis and against the back side of a block clamped to the mill's table top. Then grab either end of the table and push it to the rear and then to the front while watching the DI. Five will get you ten that the DI will move more than 0.005".

I like Don Bailey, but sometimes he seems to get things, while not wrong, somewhat non optimal. I suspect the good reputation of his company is more due to the others there and a good QC (inspection) program than to his personal shop knowledge. It would not surprise me to find a water cooler conversation there that goes something like; "He's the boss so don't argue. But when he leaves the room, do it right so it doesn't need rework".

Uncle Don always has some informative videos. I've watched about all of them on several subjects.

I have seen the Joe Pi video before. I think someone posted it in the past. I haven't tried his method yet but will just for test purposes. Going around the perimeter of a part and getting it perfectly square all depends on how well you vise is set. When I set my vise I run the dial form side to side and usually get about .0002 parallel with the table travel.

In my case for what I just tried to square up, several piece of 1/2" x 2 1/2" CF bar. Finished length 3.5" long. There was no need to mill the surfaces. So I milled each side to get the part parallel, then squared up the ends to the side. What I noticed was my two sides aren't perfectly parallel. About .0003 tenths from one end to the other in 3 1/2" of length. that's why I cant get it perfectly square. I indicated the surface of the vise from left to right and found that I have about a .0003 difference from one side to the other. I don't think it's the vise as I've checked it before on the surface plate. I believe there is some wear in the table ways.
I confirmed this last year when I milled the edge of a 6" long piece of aluminum plate. The center was slightly crowned or high by about .0003 which indicates the table ways or saddle to table ways have some wear. Typically this wear develops over years of use.

JL..................

[MrWhoopee]

Side milling the part while lying flat in the vise is the traditional approach, but I don't love the finish. Here's my solution:


It started life as a large angle plate, then project creep set in. I leave it mounted on the table next to my import Kurt copy.
The fixed and movable jaws will also bolt directly to the mill table as a two-piece table vise.

[JoeLee]

Side milling the part while lying flat in the vise is the traditional approach, but I don't love the finish. Here's my solution:


It started life as a large angle plate, then project creep set in. I leave it mounted on the table next to my import Kurt copy.
The fixed and movable jaws will also bolt directly to the mill table as a two-piece table vise.

That's exactly what I had in mind only my version was to have the vertical squaring bar extend so I could position it between the vise jaws and still use the vise for holding. But I may change my plans after seeing your fixture. My idea was to have the vertical bar adjust similar to the way yours does so if I have to mill something at a given angle I could easily adjust for it and the vise would still hold it.

I don't like the finish side milling leaves either. It varies from end mill to end mill. The more expensive end mills like Niagara leave a better side mill finish than some of the lesser quality end mills do.

JL..............

[JoeLee]

I indicated along the top of the fixed jaw. It's .003 higher on the right side. The front jaw is less than a tenth along it's length but it sits .001 lower than the fixed jaw.
Several years ago I ground them but I removed them both to measure each end. Both jaws measure 1.4715 on each end.

For some reason the fixed jaw is sitting high on the right side. I ground the 45 deg. corner clearance bevel on the back side. It was off by about .003 on the right side.
That got it down to about .0005 high on the right side. The error must be where the jaw sits on the vise. I stoned it slightly and got it down to about .0002 high on the right.
Close enough but the movable jaw still sits .001 lower than the fixed jaw. If I close the vise up on a 1/2" dowel pin and allow the jaw to rise it sets about .00005 below the fixed jaw consistently along it's length. I never relied on the top edges of the jaws for anything anyway.

JL.................