Linear Bearing for leg vise

  • Advertise with us

« back to Hand Tools forum

Forum topic by Nicholas Hall posted 12-31-2013 10:59 PM 6707 views 3 times favorited 18 replies Add to Favorites Watch
View Nicholas Hall's profile

Nicholas Hall

352 posts in 2135 days

12-31-2013 10:59 PM

I saw an interesting post about the use of a linear bearing in lieu of the traditional pin board to prevent a leg vise from racking. It looked pretty effective, and it’s cheaper and easier to install than a benchcrafted Criss-Cross. That said, I’ve never seen anyone else post a successful implementation. Are there any lumberjocks out there who have tried it? BTW, I think Richard McGuire sells a ready-made linear bearing kit in the UK, but this isn’t in my budget. I’m talking about a linearing bearing implementation using off the shelf parts. Before any mentions it, I know it generally isn’t very much trouble to adjust the pin in the traditional pin-board; I just like the idea of having automated anti-racking built into my leg-vise.

Here is the link of the linear bearing mechanism:

Thanks in Advance and happy New Year!

-- Outside of a dog, a book is a man's best friend. Inside of a dog, it's too dark to read. -Groucho Marx

18 replies so far

View richardwootton's profile


1699 posts in 1984 days

#1 posted 12-31-2013 11:11 PM

I remember seeing some one give it a try on the Work Bench Smack Down thread and if I remember right it didn’t go quite as well as planned, but still worked.

-- Richard, Hot Springs, Ar -- Galoot In Training

View jmartel's profile


7959 posts in 2178 days

#2 posted 01-01-2014 02:03 AM

That would be me, Richard.

Nicholas, I used the shaft and linear bearing idea on my workbench, and I cannot recommend it. While in theory it works, and it works in the above example, I couldn’t get mine to work properly and now have to use spacer blocks. So, all in all, it was a waste of about $75.

I’ve debated getting rid of it and going to the traditional pinned board. I’m sure I can find another use for the combo.

-- The quality of one's woodworking is directly related to the amount of flannel worn.

View Nicholas Hall's profile

Nicholas Hall

352 posts in 2135 days

#3 posted 01-01-2014 01:28 PM

That’s too bad. Have you figured out why it doesn’t work?

-- Outside of a dog, a book is a man's best friend. Inside of a dog, it's too dark to read. -Groucho Marx

View shipwright's profile


7996 posts in 2826 days

#4 posted 01-01-2014 04:02 PM

Just thinking out loud but if this is supposed to work, as I assume it is, the way a holdfast works maybe it would do better with something that wasn’t designed to slide. In my mind a linear bearing that is a perfect fit to the shaft would have trouble jamming. The longer it was the worse the problem would be.
I’m not about to argue with Marc as I haven’t tried this but to me it seems that something shorter, looser and rougher than a linear bearing might work better …....... or not. :-)
The idea is certainly intriguing.

-- Paul M ..............If God wanted us to have fiberglass boats he would have given us fibreglass trees.

View Nicholas Hall's profile

Nicholas Hall

352 posts in 2135 days

#5 posted 01-01-2014 09:45 PM

I’ve been thinking about the use of friction in a leg vise, but I can’t find anyone else who has done something like this. There is probably a reason for that :)

I was thinking that it might be interesting to experiment with clutch lining material.

The idea would be that the vise would slide as long as it was wasn’t under torque, but that as soon as torque is applied when the vise is tightened, taking the parallel guide out of parallel, it would sieze up due to the clutch lining. The clutch lining is sold by the foot in a variety of widths. For about $10, I can buy a 1” x 48” x 3/16” precut clutch lining strip to play with.

I would glue some lining to the top & bottom of my parallel guide, and some to the top and bottom of the parallel guide mortise through my bench leg. In theory, the parallel guide would slide easily when not under torque, but would seize due to friction as soon as the guide went out of parallel. In practice, I’m guessing this would just make for a non-sliding, non-working vise that get’s hopelessly seized every time it clamps. I would still love to try it of course to figure out exactly why it doesn’t work :)

-- Outside of a dog, a book is a man's best friend. Inside of a dog, it's too dark to read. -Groucho Marx

View Nicholas Hall's profile

Nicholas Hall

352 posts in 2135 days

#6 posted 01-02-2014 07:14 PM

So far I’ve heard one vote saying don’t do and nobody has responded saying it works. Surely there is some lumberjock who got this to work?


-- Outside of a dog, a book is a man's best friend. Inside of a dog, it's too dark to read. -Groucho Marx

View ekohlwey's profile


1 post in 1279 days

#7 posted 01-02-2015 12:02 AM

I recently attempted this and experienced the same negative result. Finding no other discussions of this, I thought I would resurrect this thread to share my experiences in order to warn others that may be contemplating this idea. The TL;DR (for me) is to suck it up and go with some of the nice purpose-built, well designed and thought-through hardware that is commercially available for leg vises (via folks like Benchcrafted).

Technical issues aside, the costs of creating this system are quite high. I think I invested a total of around $500, between parts and labor at my local machine shop. I see no evidence that the performance can be any greater than the St. Peter’s Cross systems created by Benchcrafted (for example) but the risks posed by the design challenges are much more significant.

I think that there must be some significant details missing from the build shown on TWW’s site. It seems unlikely even theoretically that such a design could work, due to the very tight tolerances required of the bearing, and the extreme load that would be produced in the linear bearing.

I used a ceramic bearing that allows for approx. 2 degrees of shaft play, and tolerates very high loads compared to ball bearings (I think up to 20,000 lbs), thinking this would be a more robust configuration. The shaft racks severely in the bearing (visibly more than 2 degrees) and as a result is probably also destroying the bearing. It gets stuck against the floor and is a bugger to unbind.

Seeing this result, I am skeptical that a ball bearing with lower tolerances and load rating could possibly work.

As jmartel notes, it clearly has worked for someone, but the details of their build and reproducibility make this a bad bet for most folks.

View Woodknack's profile


11826 posts in 2408 days

#8 posted 01-02-2015 08:49 AM

Better alternative

Click for details

-- Rick M,

View Jsavalla11's profile


1 post in 624 days

#9 posted 10-08-2016 06:02 PM

I think to solve racking problem, you’d have to increase the length of the linear bearing shaft. If a tolerance of play at 1” long bearing is say 1/32’ that’d suck. Increase the same bearing to 4” and the length of the vice shaft inside the linear bearing would probably be 1/128”. The loads are probably not even close to what they can handle. Get the double wide flange mounts. I’m going to try it if I ever start on my roubo.

View Woodknack's profile


11826 posts in 2408 days

#10 posted 10-08-2016 11:35 PM

Yeah I don’t see any reason it wouldn’t work if the bearing service is long enough and attachment to the vise face is rigid.

-- Rick M,

View unbob's profile


810 posts in 1932 days

#11 posted 10-09-2016 06:29 PM

I will look for a photo of my traditional leg vise I rebuilt from a 100yr old one. I find the racking action important to grab the hard to hold pieces. In this way, adjusting the pin location to effect the jaws to contact more at the top or pinch the work. If the jaws contact even a little at the bottom, the part will slip out. The linear bearing would make for no further adjustments for jaw angle.

Here it is holding a #7 handplane for hand scraping flat, a very slippery item needing just the right amount of top pinch to hold solid, using the lower pin location to achieve the jaw angle.
Some woods that I am working are as slippery as the cast iron plane, and need that angle adjustment.


View crank49's profile


4032 posts in 2999 days

#12 posted 10-09-2016 07:49 PM

Just thinking out loud here, but I built a press a few years ago for a manufacturer of auto components and it used four heavy duty drawer slides to acheive perfect liner motion without racking.

View cobnashine's profile


5 posts in 1297 days

#13 posted 11-25-2016 02:55 AM

I saw this article online,,

and decided to make an inclined leg vise using linear bearings, and it racks something terrible. Here are some pix:

So there are 2 steel shafts, each riding in 2 linear bearings (all from McMaster-Carr), so the threaded screw doesn’t have to apply any torque to the chop. Handwheel moves the chop in and out freely, but when I clamp the work piece, the bottom of the chop moves toward the bench a half inch more than the top. So the chop is skewed, that is, it leans in at the bottom, and makes it difficult to secure the workpiece.

Any suggestions? I think the wood of the chop is not sufficiently hard or strong to prevent the steel shafts from tilting as the hand wheel tightens the jaws of the vice onto the work piece. I placed a square on each shaft, and before tightening, all was perpendicular, but the more force the chop applies to the workpiece, the more “daylight” can be seen between the blade of the square and the inner surface of the chop.

At worst, I’ll rebuild the thing and use the criss-cross from Benchcrafted.

-- Hank in Pennsylania

View crank49's profile


4032 posts in 2999 days

#14 posted 12-21-2016 02:56 AM

Why not build these with two screws tied together by a chain drive?
No racking then, and perfectly parallel movement.
You could put the sprockets on the back end of the screw shafts so they would be under the bench and out of sight.

View Lazyman's profile (online now)


2062 posts in 1416 days

#15 posted 12-21-2016 03:22 AM

I just looked at the video for the criss-cross from Benchcrafted. If the video is accurate, at $99-$139 I am not sure why you would use anything else, especially if the linear bearing approach is going to cost you $75 anyway.

-- Nathan, TX -- Hire the lazy man. He may not do as much work but that's because he will find a better way.

showing 1 through 15 of 18 replies

Have your say...

You must be signed in to reply.

DISCLAIMER: Any posts on LJ are posted by individuals acting in their own right and do not necessarily reflect the views of LJ. LJ will not be held liable for the actions of any user.

Latest Projects | Latest Blog Entries | Latest Forum Topics