Split Roubo Workbench #16: Leg Vise - The Chain Leg Vise version.

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Blog entry by lysdexic posted 07-17-2012 08:26 PM 13118 reads 14 times favorited 31 comments Add to Favorites Watch
« Part 15: Leg Vise - The BenchCrafted version. Part 16 of Split Roubo Workbench series Part 17: Getting ready for assembly »

Jim (Boatman53) has come up with a new/old way to keep the leg vise parallel without the need for a pin. Disclosure: There is no monetary or financial benefit on my part. Also, this is not a review or endorsement. I plan on doing a objective review once I use it for some time. If you have questions that you would like to ask Jim directly you can email him at

Ancora Yacht Service


Before permanent installation into the chop, I went ahead and made the notch on the parallel guide. It turns out that the screw was a little long but that is because I cut may “decorative” bevel without planning ahead. Regardless, It filed down easily.


Before dis-assembly, I marked the bottom of the big screw nut plus threw an 1/8” in for safety. 1/2” below that is the centerline for all the boring. I transferred this line to the front of the leg and chop.

Next, I took apart the BenchCrafted version. First to do this “retro-fit” but also shave the pencil marks and “road grime” from the chop and leg.


First, the bronze grommet gets a 1” counter bore. After that I drilled a 5/8” hole through the chop….......

and leg.


In the above picture you can see the layout for the mortise version of the chain drive leg vise. There is also a surface mount bracket version that would obviously be easier if this was a true retro-fit. A 1/4” straight router bit keep the mortise bottom square to the surface. To me this is important because this will define the axis of rotation for the sprocket. If I were more skilled then a mortise chisel could execute this chore adequately.

At first it is tad tight but with a little paring it fits nicely.

2 retaining screws keep the axle in the mortise. These are not critical as the resultant vector is down and into the leg.


Jim provides a 3/8” spacer to help alignment of the lower bracket. The holes are marked with brad point bit.


That is about it. The leg vise is re-assembled.


The front roller bracket is still used with this system. Actually, looking at that picture, I need to adjust the wheel up a smidge. The back roller bracket is removed as you can see the tapped holes under the chain.



- I wish I had taken a picture of the kit components before install

- there is no decline in the over all smoothness of the vice

- I do not need a pin anymore

- the parallelism is easily adjusted by the nut on the parallel guide

-Some (bertha) will object to the two-tone :^)

-I had to try the crushed can trick. Just had to. I even shot a cheesy video but it is too awful to post.

-You may ask why I went through the trouble of making the BenchCrafted version first. Well, in all fairness, I didn’t know if the chain drive leg vise would work. If it didn’t, then I could go right back to the BC version before assembly. But that is not going to happen.

Now, I am up to date and current on these blog posts. Damn, this a bit of work.


-- "It's only wood. Use it." - Smitty

31 comments so far

View Brandon's profile


4151 posts in 2648 days

#1 posted 07-17-2012 08:33 PM

Great post, Scott. Let’s see the cheesy video!

Also, I want one of these mechanisms . . . badly.

-- "hold fast to that which is good"

View Mosquito's profile


8746 posts in 1989 days

#2 posted 07-17-2012 08:39 PM

How well does it work when you’re closing it? I see how the chain drive would open it nicely, but not as much with closing. Or does it really just stop the bottom from pulling in once the top is clamping something?

It looks really great, and I want one…

-- Mos - Twin Cities, MN - -

View Brit's profile


7095 posts in 2539 days

#3 posted 07-17-2012 08:40 PM

Very interesting Scott. Nice install and thanks for the detailed pics. Congrats to Jim too.

-- - "The hand speaks to the brain as surely as the brain speaks to the hand." Frank R. Wilson

View Don W's profile

Don W

18376 posts in 2264 days

#4 posted 07-17-2012 08:47 PM

do you have to ware a sailors cap to navigate it? I’ve got to let this sink in. To much technology top fast. I’ve got brain freeze.

Beautiful execution.

-- - Collecting is an investment in the past, and the future.

View lysdexic's profile


5211 posts in 2319 days

#5 posted 07-17-2012 08:47 PM


I guess I should quit calling it a chain “drive.” The chain does not drive anything but it is slaved to the postion of the chop which driven by the screw. Therefore, it doesn’t matter if the vise is going in or out. The chain foillows along and keeps the chop parallel.

The overall action may be a slight bit more jerky than with two rollers but you can clamp any object of any size without racking and without a pin. Cool.

-- "It's only wood. Use it." - Smitty

View Mauricio's profile


7127 posts in 2848 days

#6 posted 07-17-2012 08:50 PM

Damn thats sexy!

-- Mauricio - Woodstock, GA - "Confusion is the Womb of Learning, with utter conviction being it's Tomb" Prof. T.O. Nitsch

View Smitty_Cabinetshop's profile (online now)


14399 posts in 2315 days

#7 posted 07-17-2012 08:53 PM

I think my stretcher locations might prevent me from using this… Must check…

-- Don't anthropomorphize your handplanes. They hate it when you do that. -- OldTools Archive --

View Mosquito's profile


8746 posts in 1989 days

#8 posted 07-17-2012 08:56 PM

I knew it didn’t actively push or pull the bottom, I was just curious if it would go slack when you moved it in or not (from the bottom of the leg vise not moving with the top right away)

-- Mos - Twin Cities, MN - -

View Don W's profile

Don W

18376 posts in 2264 days

#9 posted 07-17-2012 08:58 PM

so the holes are drilled in case your change your mind?

I hate it when it goes slack, (ok, just can’t write the rest)

-- - Collecting is an investment in the past, and the future.

View sb194's profile


195 posts in 2715 days

#10 posted 07-17-2012 09:25 PM

That is very cool. Still can’t wait to see the completed bench.

View lysdexic's profile


5211 posts in 2319 days

#11 posted 07-17-2012 09:57 PM

Chris, I don’t mean to insult you at all. I just realized i was using some misleading verbage.

Regardless, the chain may “bounce” with slack momentarily as you change directions from out to in.

-- "It's only wood. Use it." - Smitty

View lysdexic's profile


5211 posts in 2319 days

#12 posted 07-17-2012 10:01 PM

Don, exactly. I had every intention to build per the BC plan. There is no better time to execute that plan than now. Like I said – I didn’t know if the chain leg vise would work. As a bonus, it demonstrates how one can retro-fit a bench.

-- "It's only wood. Use it." - Smitty

View ShaneA's profile


6773 posts in 2295 days

#13 posted 07-17-2012 10:08 PM

Looking good Scott, I like the lever cap shape you gave it. Kinda stinks about the rusting aspect. There should be metal polishes out there that should slow or stop that, no?

View lysdexic's profile


5211 posts in 2319 days

#14 posted 07-17-2012 10:13 PM

Shane – I don’t know if it is the environment or if I exude some caustic film from every pore.

-- "It's only wood. Use it." - Smitty

View Boatman53's profile


1022 posts in 1893 days

#15 posted 07-17-2012 10:45 PM

Nice job Scott. Smitty you may be able to use the stretcher to hold one side of the sprocket. That is what I did on my bench that was planed around this chain device. I put the beam low and the stretcher holds one side of the sprocket. Post a photo of that area when you get a chance and I’ll see what can be done.

-- Jim, Long Island, NY home of the chain leg vise

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