Workbench v2: Leg Vise

With the large frame components done, I could now work on the bench’s vises. Like everyone else in the known universe, I got a Benchcrafted Glide leg vise for the front (thanks SWMBO!).

The installation is not what I’d call easy, but it’s not ridiculously difficult, either. The first step was to put the holes in the chop (a big chunk of beech I found in the pile), and the leg.

For the chop, you’re supposed to put a shallow hole for a washer around the screw clearance hole–a 1.75″-diameter hole. The only thing I had in that size was an expansion bit. Now, those bits are not known to be terribly good even in soft woods, much less something like beech, but thankfully, this thing needed be just 3/16″ deep, so I used it mainly for the cutting spurs to get the circle.

Now, the main screw clearance holes in the chop and the leg are supposed to be 1.5″ wide, and I didn’t happen to have a No. 24 bit, either. I was all ready to wimp out and turn to the dark side, and in fact, I’d brought the chop and the leg to my friend Jasen’s place to make use of his drill press and Forstner bit. However, while preparing, I poked through his box of auger bits and found a No. 24 Irwin solid-core bit. Arrangements were made to abscond with the bit, and so mad props to Jasen for letting me do so!

I used my 14″ sweep monster (a Millers Falls #730). For those of you who have never seen a bit this large, consider the following: The brace’s chuck was just barely able to hold the bit, and only because they tapered the shaft thinner near the end.

This is the type of job that you have to break out the squares to keep the bore straight:

This is a big job, and it was no small amount of effort to turn the brace. The most difficult part of it, however, was to keep everything straight while exerting enough force.

Once the hole was through, I knocked out the waste in the outer washer hole–my Veritas mini router plane struck again:

So, when everything was said and done, I had two holes: one fancy, one not-so-fancy, both big:

After this, it was off to mark, drill, and tap the holes to attach the handwheel and screw to the chop. This is a particularly tricky job–you really need accurately lay out and drill those holes. (Thank goodness for auger bits.)

Now, a suspicious reader may have examined some of the photos above and noticed that I was using a peculiar piece of sacrificial wood underneath the chop for blowout prevention and lead-screw continuity:

This might qualify as the dumbest use of cherry in history, but notice the check (actually, compound checks) in the center. This precluded me from making a saw handle or something nice with it, but after I finished wrecking the center, I sawed off the usable wood on the sides for the Glide vise’s roller brackets:

This is sort of more silly luck than clever, I’d think–this offcut was the only thing I had around that wouldn’t require sawing up another board just for a couple of 6″ blocks.

I should also mention that with this bench, I am not trying to use a bunch of different woods to make it a showcase piece–I just want the thing to work. So, having now used three woods (the other two being douglas-fir and beech), I figured I’d use whatever I could find for the parallel guide, and I found none other than the last offcut of that nasty birch that I used as a secondary drawer wood on the second nightstand project.

Another thing that you may have noticed is that the hole in the leg isn’t horizontally centered. This is where I might eventually look like a goat, but I decided to try something a little different with this vise. Looking at the design of a leg vise and the diagonal one that Schwarz used in the “English Workbench” in his first workbench book, it dawned on me that the spot with the highest and most stable gripping power on a leg vise is directly opposite the parallel guide. On most of them, that’s in the center of the chop at the top, but that’s not where you would clamp a number of workpieces because the vise screw is in the way.

But on the diagonal vise, you don’t have that problem. So for better or for worse, I decided to put the parallel guide off to one side of the chop, and in doing so, move the “grip sweet spot” (or whatever you want to call it) off-center at the top of the chop, so that it wouldn’t be right above the screw. Here’s a shot showing the mortise for the parallel guide and a dowel leading to where that spot will be on my bench:

The off-center hole in the leg is part of the design. The idea is to place the spot with the maximum force somewhere around the area where the side of the leg meets the top.

In addition, by moving the parallel guide over to the side, I could move the guide’s clearance mortise in the leg over to the side. There, the parallel guide would slip neatly alongside the giant lower side stretcher rather than above or below, sidestepping one of the common issues when installing a leg vise.

It’s easiest to show this in the nearly finished installation:

Now, at this point, I should mention that more often than not, when you try to get clever, you end up shooting yourself in the foot (especially if you’ve never done this before). To put it lightly, this configuration does not come without difficulty. In addition to having to be extra careful with your layout, you’re also introduction an element of imbalance to a vise that really seems to have been designed to be horizontally symmetric. It goes without saying that when you go tinkering, the chop will want to lean in one direction, possibly binding the vise screw and sliding the parallel guide up against its clearance mortise.

To my surprise, it’s been working well so far. It took some fine-tuning, but the the parallel guide rollers, when set just so, seem to do a good job at supporting a good deal of the weight of the chop. The acetal bushing that comes with the Glide is also instrumental in keeping the chop inline. As an extra measure, I reduced the weight of the chop a bit by sawing off a bit of the lower right, but this may have just as well been to be able to use the offcut for something else.

I still might get burned by all of this, so let’s see what happens. I’m really due with this project–I also lucked out with the length of the vise screw and parallel guide. When vise is closed, they are about 1/8″ from hitting the inside of the rear left leg of the bench.

Now at this point, I have to make a confession: I used a power tool in the vise construction. It’s not what you might think, though. You see, the Glide vise requires you to tap threads in wood. Miraculously, I somehow already had the four taps required for the job (picked them up at a garage sale once but never used them), and I had everything I needed to drill the initial holes for all of the taps by hand. However, what I didn’t have was a tap wrench with a collet large enough to hold the two largest taps. At that point, I had to either buy another tap wrench or think of something else. The taps fit in a brace chuck, but the action on a brace can be a little bit too wobbly for this job. I decided that I didn’t have the stomach to go out and buy some (likely crummy) tap wrench for just this time, so I’d actually follow the instructions for the Glide for a change. I chucked the two big taps into my cordless power drill and threaded the holes with the dark side of the force.

It felt kind of dirty.

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