My Roubo, part 16

(Go back to part 15)

I had originally said I wouldn't add the crochet. But I wanted to keep it authentic. This bench comes from a period where hand tool work was a high art. If they thought it was an essential appliance, then I wanted to give it a try.

My solution was to add a removable crochet. This wouldn't be as solid as a fixed crochet, but would allow me flexibility. I had a cutoff from the glued-up stretchers just the right size.

I formed the curves the same way as the sliding deadman.

I found the surform rasp a little better to use on the concavity.

The surform plane worked well on the convex curve.

Gotta chamfer all the edges!

Boring the hole for the post. Since the post will be fixed to the crochet for insertion into the top, this needs to be a continuous straight line for a good fit.

Trimming the post after bottoming it in the hole.

In order to get a good solid attachment to the crochet, I sawed a kerf down the post and drove in a wedge. The wedge needs to be aligned perpendicular to the grain to avoid splitting the crochet as I drive it in.

After cleaning up the end of the wedged post, I bored a cross-pin hole through the end of the bench and the post. Then I inserted a removable pin. This locks the post in place. The crochet moved out a bit as I bored the hole, leaving a small gap, so I added a layer of PSA sandpaper as a shim. That makes it draw up tight against the top when the pin is inserted.

Testing the crochet.

Under pressure from a workpiece, the crochet had too much give, so I drilled two small holes for alignment pins.

The crochet removed. You can see the sandpaper shim layer, the main post and alignment pins, and the withdrawn locking pin. I glued a square nut onto the end of the pin for easy handling and trimmed it off flush.

The alignment pins made a big difference in stiffness. Still not as solid as a couple of lag bolts, but it holds quite well. We'll see how it stands up over extended use.

Speaking of shims, I had another brainstorm. The indexing holes in the leg vise parallel guide are spaced about 3/8" apart. When something in between those points is in the vise, it suffers the same racking as a parallel clamp where the two screws are not set equally.

So I bought a deck of large flash cards at the toy stored and made a set of shims to allow fine spacing. This in turn allows fine parallel adjustment of the leg vise for maximum grip. Just like a parallel clamp standing on end.

A stack of 10 of these cards measures out at 0.14" with a dial caliper, so they average 0.014" each.

Finally! The completed bench, with leg vise, planing stop, crochet, deadman, Wonder dog, and holdfasts.

I kept a log of all the time I spent on the bench. Spread over 20 calendar weeks, it totaled 88 hours and 26 minutes. There was probably a good hour or so spent fiddling with the camera, so call it 87 hours.

And now a final treat. I made a video demonstrating the features of the bench. It's in two parts due to YouTube limitations on length. NOTE: I have seen problems with these showing up with Firefox on Ubuntu Linux, so if you don't see them below, search for them on YouTube with by clicking here.