I’ve been working on the end vise. I wanted to get that mounted next so I could figure out if it would impact the placement of the top on the base.
I wanted a twin screw vise for dovetailing. As I mentioned previously, I’m using two Lee Valley end vise screws for the end vise. I thought about buying their twin screw (Or Lie-Nielsen’s, or Hovarter) but couldn’t come up with the money. I also considered building a Moxon vise for dovetailing and just using a more simple end vise, but I decided I didn’t want something else I needed to store.
So, I used 8/4 maple, one thickness for the rear jaw and two thicknesses laminated for the chop. I think the chop is overkill, but I ended up with 16.5” between the screws and didn’t want to find out that I had flexing issues with a single 8/4 thick chop after I was done.
The chops are a bit over 7.5” tall. This is more than my jointer can handle, so I flattened one side with my jointer plane and then ran them through the planner.
When I was done I had 30# of maple. Then I reconsidered how I was going to mount it. I had planned on using lag screws to fasten it to the edge of the top. Since this joint would see all the weight of the vise continually, as well as the weight of anything I clamp, and any pounding I do, I was concerned the lags would loosen up over time. I thought about adding a spline to provide more support, but I couldn’t come up with a good way to cut the groove in the bench top accurately. I also considered biscuits, but I don’t trust them to add strength. I finally decided to add three 7/8” hardwood dowels. I drilled 1” into the bench top and into the rear jaw. Then I used 4 3” lag screws to secure it. It turned out well that I added the maple strips to the top, I was able to run all four lag screws into maple instead of the LVL. I don’t know how well it holds screws, but now I don’t have to find out.
A little while back I watched a video about twin screw installation posted by LJ Bill Schenher III, http://lumberjocks.com/AWSIII/blog/27696
He talks about mortising the nuts into the rear jaw. At first I wasn’t sold, but the more I thought about it, the more it sounded like a good idea; Thanks Bill!
The taper on the nuts is only 1/16” per side over 1.75”. I drilled through at the small diameter and then used a rasp to open up the taper. Even in hard maple, it only took about 45 minutes of filing and trying to get them to fit pretty well. The height of the nut fit perfectly into a 8/4 board; with the flange flush the front of the nuts doesn’t quite stick out past the front of the rear jaw.
After drilling out for the dowels, the lag screw (and their counter sink holes,) and the dog holes, I was ready to assemble. The nuts and garters attached easily; just drilled pilot holes and ran the screws in. I did run into one problem I’ll pass on. To drill the dog holes I got a 3/4” up cut router bit, but that’s not long enough, so I also picked up an Irwin 3/4” auger bit from Lowe’s. This was a traditional single screw auger. I figured I start the holes with the router and finish with the auger. The dog holes in the end vise chop were my first try. Since it’s a small piece I used the drill press. Now I have a small bench top drill press, but it couldn’t turn the auger bit. It would run the lead screw in and seize up. I tried it with a corded hand drill and no luck there either. I ended up using the 3/8” auger I got for the drawbore holes and drilled to my depth, then I used the 3/4” auger to finish. Since the lead screw had nothing to grab I could control the rate of feed with my hand drill. I guess this is how I’ll have to do my dog holes, which will be a bit of a PITA (route to max depth, use 3/4” auger to mark center, drill through with 3/8” auger, finish drilling through with 3/4” auger.) I was looking at buying a hand held bit brace for this job, but couldn’t find one with a swing more than 10”. Anyone looking to sell one?
It took a little fussing with the dowels to get them to fit, as my holes were not perfect, but I got it to fit, and the dowels are tight. At this point I’d say all the weight is on the dowels, and I feel pretty sure this won’t move. However, if it does, I decided not to glue anything, so if I pull out the lag screws the whole end vise will come off. This also gives me the flexibility to replace the vise later if I don’t like using this.
The rear jaw ended up a bit lower (~1/16th) than the top, and the front chop a bit lower than the rear jaw (again ~1/16th), but not bad, and it shouldn’t effect the use of the vise. If I was doing it again I would add more of an intentional offset and plane it down. I aimed for flush, but it drooped slightly.
I did weigh some of the parts so far, the top was 175#, the base 83#, and the end vise assembly 45#; 303# and still have the leg vise chop and dead man to add. Still plenty to do; the dead man, getting the top mounted, drilling the dog holes, then the leg vise chop, and finally a shelf under the bench.
Thanks for reading.