Off Center Dog Holes and Vise Racking

[Brendan Dahl]

I’m just about to finish up my roubo style bench and would like to put some round dog holes along the front edge. My plan was to use a metal quick release vise as a tail vise, mount it flush with front edge, and put dog hoes about 2” in (on center) from the front edge. The vise I was looking at is 7” wide which means the dog hole would be about 1 ½” off from the center of the vise.

Do you think this would cause too much racking? If not, could I even go with a larger 10” vise and still be fine?

Last, its unfortunate the way Jorgenson designed their smaller 7” vise. I originally planned to use it but the back piece that mounts to bench is the same as the larger vise so it’s actually 10” wide, which would put my dog holes even further off center.


Thanks,
Brendan

[Jim Foster]

I ended up skipping a wagon wheel vise ion mine, I plan on getting the round dogs and LV doghole clamping device. Why not center the holes on the vise center?

[glenn bradley]

Do you think this would cause too much racking?

Yes . . . . sorry :o. Even a bit off center-line will cause some racking. There are various methods to control the "free" side of the jaw. There are discs that spin out on threaded shafts, stepped blocks or paddle sticks like I use. Quick to make and they solve the problem. shown here solving the opposite problem of which you speak.

[Brendan Dahl]

I ended up skipping a wagon wheel vise ion mine, I plan on getting the round dogs and LV doghole clamping device. Why not center the holes on the vise center?

I could do that instead. As I don't have much experience with a roubo style bench I was just going to follow the advice of Chris Schwarz and put my dog holes pretty close to the front. I believe he said it makes it easier for working with planes with fences such as rabbet or plow planes. If you look at his latest roubo his dog hole is off center from his vise, but his vise is a different style than most modern ones.

[James Scheffler]

The round dog on the bench may tend to rotate and skew the board being held. Does the vise have a square or rectangular dog? If I'm visualizing this right, it seems like the end of the board may not sit quite square to the face of the dog on the vise. It might hold ok, but the corner of the dog might leave a mark on the board.

It isn't that hard to build a wagon vise, so that might be a better option. It also can be cheaper. On the other hand, a 2nd vise on the end might be useful. Mine doesn't have one....

Jim

[Zahid Naqvi]

Brendan, sorry I'm not much help. I used the exact same setup as yours, i.e. a quick release metal vise as the tail vise. I too have not drilled the dog holes yet so I'll be watching this thread for any advice that comes along. I can offer some observations though, keeping the dog holes close to the front apron is important for a couple of reasons; first this allows you to keep your work close to your body and as such makes it less strenuous, secondly this allows you to use narrow stock and molding/beading/rebate planes on them much easily. Now that I think about it when you clamp something in a tail vise against a bench dog you are not really exerting a lot of pressure, this is just supposed to keep the board in place for planing etc, the brunt of the force must be borne by the bench dog.

[Jessica Pierce-LaRose]

This is why I was thinking of using the Veritas tail vise (http://www.leevalley.com/US/wood/page.aspx?p=65746&cat=1,41659) on my planned bench, seems like an easy to install vise that puts the dog holes close to the edge.

[Mike Brady]

It depends on your expectations of the vise and the quality of its make. If you are concerned about using a QR vise in the end position as a means of having a "moving dog", then having the dog an inch and one-half off center should not present a significant racking problem when using a dog in the outer jaw. I say this because the the tension on the board from the vise does not have to be very great to hold it securely. I do this on my bench using round brass dogs. I have never had a problem with this setup. I find that the dogs will self-adjust if they need to rotate slightly to counter any racking. On my Record vise, if I keep the dog holes for the moving dog inside the boundaries of the jaw casting, the racking is minimal. In the photo below it is pretty well centered in the vise and I could have moved the vise a couple of inches closer to the front if I wanted to follow C. Schwarz's recommendation and have the bench holes in the second lamination of the top.

Looking at those photos, I would say that, yes, that vise will rack when boards are clamped in it because the wood jaw chop is so wide. You can always move the vise up to the edge of the bench and have a asymetrical chop if you are worried about your particular vise racking. I find that I seldom clamp boards vertically in my end vise to work on them. All of that type of work is done in my front vise. I usually keep a piece of 1/2" poplar in my end vise to use for setting my plane iron depth setting.

http://i234.photobucket.com/albums/ee300/finefettle/newbench006.jpghttp://i234.photobucket.com/albums/ee300/finefettle/newbench008.jpg

[Chris Griggs]

My end vise is a 7" QR cast iron vise, and I have offset the dog holes as you describe. I have had NO issues with racking. I'm sure some racking occurs but it hasn't affected anything when I clamp between dogs. When clamping between dogs for face planing you really shouldn't use too much clamping pressure anyway.

199592

[Brendan Dahl]

Thanks for all the suggestions. What Chris Griggs has done is pretty close to what I was planning to do. Now I just need to order a vise. I'll probably get the Lee Valley one.

A little off topic, but last weekend I picked up an interesting little quick release vise at a junk/antique store. The quick release works by only having part of the rod threaded and part of the nut threaded. At first it seemed to work perfectly, but the threads on the nut part are pretty beat up and slip or won't engage in certain positions. Seems like this design would be nice for an end vise where you really don't need much clamping power. The front has "Patented" on the top and "The Eliott MFG. CO. Milford Conn" in the middle. I can't seem to find a patent for it though.
199692199693http://www.sawmillcreek.org/images/misc/pencil.png