I needed another drill press vise. So I made one. I'm so happy with it I thought I'd detail how it was done and provide drawings on my website. (Translation: I feel like bragging.)
I started with a piece of 1-5/8" wide 1/2" thick cast aluminum bar, about a foot long, from which I cut three 1-5/8" pieces. Steel would be better, if you have it. In my junk pile I found a round metal cup 1-3/8" in diameter, but I could just as easily have made it from the same 1/2" thick aluminum bar. I also cut two 3-3/16" pieces of 3/8" drill rod, and a 3-9/16" piece of 1/4" drill rod.
Start by making the slide rods. It is best to turn the threads on the lathe to assure that they're perfectly straight. Besides, I've found that dies require so much torque that the drill rod gets bunged up in the vice or lathe, spoiling the smooth surface. At the very least, start the threads on the lathe and finish them with a die held in a vise with soft jaws.
Drawing 4. Slide (1 of 2)
The unturned parts of the rods must be exactly the same length, though they don't need to be exactly 2½" long. If they're different lengths, the jaws of the vice won't come out parallel.
Once you have these, you have a way of mounting the jaws and back end in the lathe to bore perfectly aligned holes. Of course, if you have a 4-jaw chuck, you don't need to worry about it.
(The "back end" is what I'm calling the piece through which the screw goes - it's on the right in the above picture. I don't know if this piece has a proper name or not.)
The trick to making the following three pieces is to get the holes in each piece in perfect alignment, yet not make them any larger than is absolutely necessary. I tried measuring carefully, and while I came very close, I was off enough that the jaw would bind as it moved.
Let me start by saying that the following proceedure is not how I did it - this is how I should have done it, and how I actually did manage to fix all the problems caused by my not doing it this way in the first place.
Drawing 1. Back End
Drawing 2. Fixed Jaw
Drawing 3. Moveable Jaw
Drill the 13/64" holes in the fixed jaw and tap them 14NC-20 (again, make sure the threads are straight!). Carefully superglue all three pieces together, making sure the edges are properly and the pieces are in the right order (fixed jaw, moveable jaw, back end) and facing the way you want them in the completed vise. Screw one of the slide rods into the back of the fixed jaw and mount it in the lathe.
Using a tailstock mounted chuck, step drill the moveable jaw and back end to 1/4", 1" deep. Switch the slide rod to the other hole and repeat.
Carefully break loose and remove the back end, leaving the back of the moveable jaw exposed. Bore the 1/4" hole to 11/32", 1/2" deep (careful not to bore into the fixed jaw) and ream to 0.376". Move the slide rod back to the first hole and repeat.
Now assemble the whole thing, but without the screw (there's no hole for it yet). The moveable jaw should slide nicely on the slide rods without much play and without binding.
Now c-clamp the moveable jaw to the back end, and drill them to 13/64", 3/4" deep. This will make the hole in the moveable jaw only 1/4" deep. Make sure the drill press table is perfectly square to the bit!
Disassemble the vice and enlarge the hole in the moveable jaw to 1/4". Tap the back end 1/4NC-20.
Turn the 1/4NC-20 threads of the screw on the lathe. It is important that they be straight to avoid binding.
Drawing 5. Screw
Drawing 6. Handle
Screw the screw (!) into the back end with the unthreaded end toward the moveable jaw, and reassemble the vise.
Screw a 1/4" nut onto the end of the screw, followed by the handle, and tighten them against each other. You may notice from the picture above that this isn't how mine is made - the piece I used for a handle had a 3/8" hole in it. I turned a pair of nuts on the lathe to produce a shallow 3/8" sholder on them, and screwed them together with the handle between them.
You'll note that there is nothing holding the moveable jaw onto the end of the screw - I've found that this isn't a problem, especially if they're well-fitted enough that you can add a drop of oil onto the end of the screw so it will seal the hole, producing a vacuum that holds the moveable jaw in place.
Like I said - this isn't quite how I did it. I drilled the 3/8" holes on my drill press, knowing that the holes would end up a tad oversized, and hoping that I could call the extra space "clearance" and pretend I meant it to work out that way. Unfortunately, while it should have worked, I didn't get the holes in exactly the right places. The moveable jaw dragged on the slide rods, and was difficult to move. I fixed this as I described above. Unfortunately, boring a slightly-oversized 3/8" hole doesn't make it any smaller. As a result, my moveable jaw is quite loose on the 3/8" rods and rocks a bit when I clamp down on anything.
My plan to fix this problem is to:
I may also experiment with making the moveable jaw thicker.
If you build one, please send me pictures!
© 2003 W. E. Johns