|Project by KnickKnack||posted 04-13-2011 07:36 PM||6535 views||53 times favorited||7 comments|
“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!!
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.
- 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."