Shop-made clamp that doesn't "walk"

  • Advertise with us
Project by KnickKnack posted 04-13-2011 07:36 PM 7550 views 54 times favorited 7 comments Add to Favorites Watch

“Clamp” has been on my list for a very long time. Having surfed here for solutions, and on the internet in general, the “main” problem seems always to be how to attach the “business end” that you’re going to tighten up in such a way that it doesn’t “walk”.
Finally I came up with a solution, which I present here. There are also some “interesting” design decisions I made during construction – I’ll explain my reasoning.

But first up – I’m indebted to these projects…
dakremer's The shopmade clamp's secrets revealed!!
ryno101's F-Clamp
mikeberry's wooden clamp

I’ll skip the month’s worth of staring into space – the first picture shows the “business end”, put together thus…

It’s an 8mm x 100mm bolt, sitting in a recess, with a washer, and a plywood piece glued on top. Do not be tempted to make this fit tightly – you want some slop in this mechanism – just as the ones in the retail shops have. The deeper you make the hole, the more “slop” there is. You probably want to file the screw slots from the head to reduce the amount of cutting it’ll do on the washer. I’ve used beech and ply, but anything will do. Once it’s glued together you have the magic mechanism.
You can even make several – it’s simply bolted into the rest of the mechanism so you could, for example, make one with a very sharp point, or with a rubber face, or whatever.

in dakremer's clamp posting he discussed the angle necessary so you can “tilt and slide” the clamp into position. As you can see, I went for something a lot shallower. The 2 key things to bear in mind are…
  • You want to start with a snug slot the width of your clamp rail. Well, in fact, this isn’t quite true, but it’s a good place to start. In fact, I think there’s an argument for inclining it very slightly the other way. It doesn’t, in fact, have to be perpendicular – as long as the hole you eventually make through it is parallel to the clamp rail – all is good.
  • You need to position and angle the “extra slot” such that the distance between the diagonals is greater than the width of the clamp rail (the disgusting pink bit below)...

Most clamps that I’ve seen in this style have one end fixed – it’s glued to the end. I decided not to do this, but rather use the same “tilt and slide” technique for the “fixed” end too. Why?
Having made just 2 “tilt and slide” blocks, I can use them on a clamp rail of any size. I can make a few short clamp rails, and a few long (or very very long) ones, and as long as they are the same width – ie they are snug on the “tilt and slide” blocks, I can use those same blocks. I also figured that there would be time when the length of the clamp rail would get in the way – then I can just slip everything up.
Note also, that I can simply reverse the blocks and I have a “push it apart” clamp for free…

I went for a “propellor” style twist knob. Firstly, note that this component is removable, so I’m not committed to this. But it seemed an easier thing to tighten up than the traditional circular knob.

The complete schematic for the clamping mechanism looks like this…

I realise (and you will too looking at the pictures), that some of this isn’t great woodworking, but, as you can see in the last picture, it works. I daresay I’ll make some improvements when I start using it in anger, and I’ll keep you posted.

I hope someone finds this useful.
If you need further information, have comments, thoughts, suggestions for improvements etc etc, please feel free.

-- "Do not speak – unless it improves on silence." --- "Following the rules and protecting the regulations is binding oneself without rope."

7 comments so far

View getlostinwood's profile


224 posts in 2804 days

#1 posted 04-13-2011 07:46 PM

This is a great design, I’ll be using this on very shortly. Mainly because I’m to cheap to spend $20 per clamp or more.

Love the technical term “bash it in Thread”

-- The basis for optimism is shear terror

View dakremer's profile


2742 posts in 3293 days

#2 posted 04-13-2011 08:14 PM

Hey looks good KnickKnack! I like the reversible clamp idea – able to pull and push. I too, in my original clamps liked the idea of the one side not being fixed. That way you can mount both ends on different length shafts – not sure why i chose not to do that. I will next time. I haven’t made any more since I’ve built my first one (I posted) – but seeing yours, makes me want to build a couple more! They work great, and are extremely cheap! Thanks for the reminder!

-- Hey you dang woodchucks, quit chucking my wood!!!!

View David's profile


9 posts in 2831 days

#3 posted 04-13-2011 08:49 PM

Great post, I hate buying clamps (they seem over priced for their function) but you can never have too many. Maybe I’ll spend some time making my own. Thanks for the inspiration and detailed description.

-- "Delay is preferable to error." ~ Thomas Jefferson

View Albert's profile


516 posts in 3791 days

#4 posted 04-13-2011 08:57 PM

Most excellent! Thanks.

View Terry's profile


14 posts in 2986 days

#5 posted 04-13-2011 11:29 PM

That’s a great idea!! Why didn’t I think of it? I too will be making some of these very soon!
Thanks for sharing.

View mafe's profile


11741 posts in 3291 days

#6 posted 04-14-2011 12:06 AM

Really cool.
These will be in the favorites.
Best thoughts,

-- MAD F, the fanatical rhykenologist and vintage architect. Democraticwoodworking.

View TopamaxSurvivor's profile


18390 posts in 3877 days

#7 posted 04-14-2011 07:22 AM

Good idea!

-- Bob in WW ~ "some old things are lovely, warm still with life ... of the forgotten men who made them." - D.H. Lawrence

Have your say...

You must be signed in to post the comments.

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