Rogue Leather

I got a little distracted while building this, so I’ll put the whole thing up in one post instead of making you wait for it. Here’s a couple shots of the completed build, then I’ll break it down into components after the jump.

The materials:

3/4″ plywood – I found that my local Home Depot carries several grades of plywood in 23″x23″ squares at a reasonable price. The downside is that these are usually prone to having more knots than the fine-grade full sheets. One of these was enough to complete the seat, arms and the lateral supports for the legs.

2″x2″ square stock – if you aren’t familiar with wood sizes, you’ll discover that they always exaggerate the dimensions by 1/4″ in each direction, which means a 2″x2″ is really only 1-1/2″x1-1/2″ – but that’s all you really needed anyway. Usually comes in 10-foot lengths which is plenty. My original plan called for the longitudinal leg braces to be the same material as the legs, but I messed up a couple of cuts and went with some pine out of my scrap bins.

Hardware –

• a good hinge (Al used a piano hinge; I was going to use a door hinge until I realized I didn’t have room to mount it so I went with a cabinet “T” hinge – it wobbles just a touch),
• several lag bolts with nuts and washers from 1-1/2″ to 3″,
• a box of 2″ wood screws,
• a 1″ welded D-ring, (I just had to replace my original due to stretch)
• a pair of compression springs
• some mild steel, about 12″. (Home Depot only sells 3-foot lengths)
• a small bit of steel strapping,
• a handful of 1″ screws to mount the Footman’s loops and the saw teeth.
• 3  Footman’s loops and the Conway buckle (purchased at my local leather supply store.)
• Lastly, there will be a bottle of wood glue and about 30″ of strap leather cut to 7/8″.

The first question you’re likely to ask is how I got the strange angle out of the plywood on the top of the clamp arms. The answer takes a few steps. Looking at the picture below for reference, I first took a small block of plywood and sliced it at an angle turning it into a chisel-shape (1). This was then glued to the main arm of the clamp and allowed to dry, at which point I came back and sliced the resultant sandwich on the same angle (2). (I just measured 3/4″ from the existing cut.)

In the next picture, you can see how I have glued the left arm to the support blocks. (The right arm is just standing there to look pretty.) The plywood in the foreground is the seat plank, and you can see the two notches I have cut. The larger notch is for the base of the left arm, which has a matching tongue cut into the bottom of it. The smaller slot is to allow the tension belt through the seat plank – more on that later.

Considering that I’ve glued and screwed the left arm to the support blocks (cut from a 2×6) and then glued and screwed the blocks to the seat, that notch isn’t strictly necessary; it was on Al’s plans though, so I did it anyway.

Here I’ve secured the left clamp arm assembly to the seat and started mounting the front legs.

The support block has been beveled inward on each side (A) and the legs have been given a matching bevel on both ends (B). I used the scrap from the bevel cuts to make a flat surface for the clamps to grab as I glued it together. Once the glue dried, I went back and drove a pair of screws through each leg into the support block. You can’t see them here, but don’t forget the lateral and longitudinal support braces on the legs – the screws and glue at the top won’t be enough to hold them.

Now we get to the part you’ve been waiting for. In this pic, you get to see the completed clamp assembly. The belt is secured to the left arm, passes through a second Footman’s Loop, then back through a third on the left arm before it goes down through that slot I cut in the seat plank.

The arrows point out the compression springs that I drilled into the support blocks. These push the jaws open when the belt tension is released so you don’t have to worry about prying the arms apart when re-positioning the work. I bored the holes about half the height of the springs. To secure them in place, I slid a washer between the last two coils and dropped a screw down the center through the washer which is driven into the block.

Once the belt passes through the seat, it attaches to the tension arm. I’ve used a Conway buckle as an adjustment – this lets me use a single strap instead of making a two-piece belt system, and I think it gives me slightly greater flexibility of adjustment.

Here’s a close-up of the tension mechanism. The saw teeth are cut into a piece of mild steel, which is screwed to the side of the leg. Another section of steel was bent over the tension arm and bolted through. Just beyond that is the D-ring mounted with a bit of steel strapping.

To make the saw teeth, drill through the steel with a 3/16″ bit, then cut a slanted ‘V’ shape out with a hacksaw or a Dremel cutting wheel. Polish it all up with a file or a grinding bit in a Dremel.

The final step on this is going to be applying an ebony stain and finish to the whole thing, but I figured it would photograph better in the raw. I will also probably make a seat cushion for it to protect my aged behind :)

This entry was posted on Sunday, November 21st, 2010 at 12:33 pm and is filed under Projects. You can follow any responses to this entry through the RSS 2.0 feed. Both comments and pings are currently closed.