1x nut (mine is 2" long)
1x bolt that fits the nut
1x 20" of 1/4" thick x 1" flat bar
1x 5" of 1/4" thick x 1.5" flat bar
1x 6" of 1/4" thick x 1.5" flat bar
1x 2" round bar
Obviously your going to want everything as close to 90 degrees and parallel as possible so everything lines up nicely when complete.
On the end of the 1.5" bar I welded a washer for a nice clamping surface.
Draw a center line down the middle of the 1.5, 6" long bar and make a mark about 1/2" from the bottom and another 1/4" about that mark.
Sorry no picture of this step so i drew one :)
I used a drill slightly larger than the bolt and made a hole 1/4" from the top for the tightening bolt
I used a plasma cutter to make the slot for the long flat bar. Make the opening slightly to small to fit the flat bar and use a file to take it down by hand so the bar just fits in but also slides smoothly.
You don't want it to be tight but if its too loose then there will be too much play and it will operate sloppy.
This is the probably the most important part of the whole build, explained why on the last step
Protect the treads from damage of weld spatter
Position the nut on the sliding arm over the hole you drilled and weld in place.
Thread the bolt through and weld a washer onto the end. This will be he other clamping surface. Be sure to grind down the welds to a smooth finish so it damage the work piece.
Slide the sliding arm onto the main shaft and double check that everything moves smoothly, then place a tack weld at the end of the main bar to prevent the sliding arm from coming off.
Viola! finished. Grab some things to clamp together and test it out.
grab 2 pieces of wood
put them together
move the sliding arm up against the piece being clamped
tighten down on the tightening bolt and your set
notice as you tighten, the sliding bar will angle back a bit causing the two bars to "lock" together, keeping everything tight and preventing the sliding bar from moving.
If you make the opening for the main shaft too big the angle it tilts will be greater which is why you want it as tight as possible while still being able move freely
I mainly use this for clamping metal items for welding, for clamping to oft materials (ie wood) I put felt pas on the contact points.