Monthly Archives: September 2020

More Messing with Tapered Tenons

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My plans today were to get the legs onto the stand that I’m building. Things did not quite go according to plan. The first impediment was that I haven’t been too content with the way you use the tenon cutter, and it came to a head today. I prefer to twist the stock into the cutter rather than twist the cutter around because it’s easier to keep it centered that way. Unfortunately, it’s not really easy to put the tenon cutter into a vise or something to keep it put. Not like it’s easy to twist the cutter, either, mind you.

So I picked up a squared-up ash cutoff, put a rabbet into one edge, and screwed the tenon cutter into the opposite edge (it has holes and little half-moonish registration standoffs to help with the attachment):

Then I can just put it into the vise, with the rabbet registering on the benchtop. The result is that (in theory, at least), you can hold the stock parallel to the benchtop and bench front to keep it in the right place:

With this system in place, I was still having problems. The tenon cutter isn’t large enough to engulf the whole octagonal profile of these legs. I was doing a rough shaping with the drawknife and saw rasp to get a cylinder to shove into the tenon cutter, with a little transition area to the outer surfaces. I determined that you need to be fairly precise about the size of that cylinder. I’d made it too small, which resulted in tapered tenons with a long rough unshaped area between the tapered part and the transition to the octagon:

This happens because the transition area eventually meets the end of the tenon cutter and cannot advance any more. This wouldn’t happen if the tenon cutter were larger than the stock being worked (which would be the case for most cylindrical legs), or if I wanted to do a more gradual transition (assuming that I were actually good enough with a drawknife to do that). Even though this 9/16″ version isn’t the largest tenon cutter that Lee Valley offers–the 5/8″ keeps selling out too quickly–it wouldn’t make much difference here.

I decided to cut new transitions farther back in the stock and make newly-shaped cylinders bigger in order to bring the tapered part closer. Something tells me that this would be a lot easier with a lathe, but I don’t have one of those. I’d been putting it into my tail vise and just whacking away with a chisel, but the end would keep sliding around too much. So I interrupted myself again and made a stop with a mouth on one end that I could secure into two dog holes (to keep it from swiveling around):

This worked. As a bonus, you don’t need to secure it with the tail vise this way, making it really easy to turn the stock around so that you can work on all of the facets.

With this aid, I was able to shape everything a bit better and use the tenon cutter again. This made for a much nicer result:

I’m not worried about the 1/4″ between the transitions and the tapered part (this is the distance between the tenon cutter’s blade and its end).

Unfortunately, I spent so much time fooling around with these little shop aids and trying to figure out the best way to use them that I didn’t have any time to ream the holes for these things today. Oh well.

About Those Wire Hanger Models

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One small project that’s been lingering for a month or so is a narrow stand to hold some decorative stuff (such as a plant or worse). I planned to make a three-legged round-topped staked version. The difficulty is that the proportions don’t really conform to most furniture projects, so I wasn’t really sure what would look halfway decent.

Fortunately, there is a solution, described in The Anarchist’s Design Book, also referenced in a recent LAP blog post. You make a quickie half-scale model to see if it works, and if it does, transfer the angle(s) from that. So I made myself a little r = 2.5″ top and set about getting some wire hangers to dismantle in order to mock up the legs.

That’s where I came across two problems. First, there’s sort of a shortage of wire hangers in this house, and an acute shortage of ones that aren’t bent all to hell, which would make it difficult to get a halfway accurate resultant angle with the long legs that this project requires. Second, I had this difficulty: How would I get a better feel for how the legs would look meeting the top, as well as the overall weight of the legs, taking into account some of the thickness? I also didn’t know what length of leg I wanted.

So maybe I don’t have a lot of straight wire hangers around, but I do have a lot of narrow offcuts of wood lying all over the place. I decided to try drilling a hole in the end and stuffing a smaller piece of wire hanger in there:

And then, I wasn’t sure of the inset from the edge where the legs should be attached. Again, because this is not a chair, I wasn’t really sure what might be appropriate. So I drilled two sets of holes in the top so that I could play with both:

At least the sightlines for this thing are really easy to determine.

With this in place, I attached scale 30″ legs in the outer holes to see how this would look:

As I suspected, it was awkward. There were problems viewing from different angles and the proportions are also a bit unfortunate. I tried putting the legs into the inner set of holes, and that was also strange.

So then I tried scale 26″ legs, attached to the inner holes:

This seems to work better. It looks like a stand, I guess. Hopefully it does not look like a stool, though it might actually be able to perform that function.

In any case, before getting the resultant angle, I just tried fixing the wires in place with “Shoe Goo” to see if I can keep them from wriggling around so much. (Others use epoxy, but I don’t have any of that right now.)

The Roubo-Style Panel Clamp

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This was going to be my year for getting enough clamps: I was to troll the tool sales and estate sales to get what I’ve been lacking. Then you-know-what came around, and that plan whimpered and died. As fate would have it, I’ve got an upcoming project that requires more clamps than I have.

Perhaps I was fortunate that I was reading the Roubo translation from LAP recently, and of course Roubo talked all about clamps. He described a panel clamp made from two boards that he called “twins.” He said that “the use of these tools is excellent,” and his recommendations are not to be taken lightly. OK, whatever, it looked reasonable, so I wondered if anyone in the 21st century had made them. I should have guessed that Don Williams had done it; here’s his blog post. There’s a snippet of the Roubo plate in there. Also, keep in mind that even though we’re calling them “Roubo clamps,” we don’t really know how the form evolved over the years to the form he described.

The construction of these is simple enough that it was definitely worth trying. I grabbed some southern yellow pine 2x4s and put a bunch of holes in:

Hand tool disclaimer: I used my drill press. Sure, I could have used my brace, but it would have taken a lot longer, and this is one thing that a machine actually does really well.

The holes are alternately offset like Williams did. It seemed like a good idea at the time. He used a mortising machine to make 1/2″ square holes. I planned for 3/4″ pegs, and I didn’t like the idea of using round pegs, so I needed to square up the holes. With no mortising machine of my own, I just went at it with the biggest mortise chisel that I own:

Thankfully, these don’t need to be appearance-grade. And yes, I chopped halfway in from each side, and yes, there’s something underneath the wood to keep from putting (any more) nicks into my bench.

This was something of a chore, but not awful. After that, it was simply a matter of resawing, making the pegs and wedges, and before long, I had three twins:

I tested them on some boards that were lying around:

These seem to work well. I pounded the wedges in pretty hard. Using them requires some acclimation, so I guess another reason to use liquid hide glue is so that you have enough time to put them on. Although I’m using double wedges here, I might change to single ones for the simplicity.

Being southern yellow pine, I think they’ll be strong enough. Roubo describes beefier things: roughly 4-5 inches wide, and 2 inches thick (but is this per side or for both twins?). His described mortises and pegs are 1.5 inches wide–four times the volume profile. But from what kind of wood would he have seen these made? Oak would be very strong for the pegs, but its tendency to split cleanly might be something of a concern for the twins. Beech wouldn’t have that kind of problem. Or what if it were a wimpy sort of thing?

Oh well, I don’t think that’s something I need to concern myself with that until I manage to break these.

Quickie: Back Door Shelf

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A secondary title would be “A Study in Overthinking.” There’s a spot near our back door where we’ve been wanting to put up a small shelf with some knobs or hooks or something underneath. I decided that it wasn’t worth procrastinating any longer, so I grabbed a piece of eastern white pine, flattened and thicknessed it, and set out to do the actual construction. At first, I thought that I’d make some sides as brackets and use cut nails to put the whole thing together (too much “Anarchist’s Design Book,” you see).

So I plowed a groove into one of the boards that was to be the back. This would accept the shelf:

I had to do this in three stages because (a) I don’t have many blades for the plow plane, and my widest one was a little too wide, and (b) I failed to think ahead that I could have just thicknessed to the width of that wide blade. When you’re overthinking, you wouldn’t accidentally want to think of something that makes sense, right? At least I rejected the sliding dovetail idea.

Then I quickly evened out the bottom with a router plane, and got to fitting the shelf into the back. At that point, I tossed the nail idea out the window because it was faster to glue the thing in place:

The remaining work would be to make the sides that would act as brackets. I was still planning to nail those on, but then I realized that because I glued it, this thing was probably already stronger than it needed to be. There was the option of omitting the brackets altogether and letting the shelf “float,” but I didn’t think that look would fit the intended setting.

My first thought was to just make diagonal braces dovetailed into the rear and top, but partway into making the brace, I decided that this was a dumb idea. It helped that I was feeling lazy. I ended up just mitering the brace with no additional joinery, and just glued them on:

I didn’t even bother to use clamps. In other applications, this might strike one as flimsy, but remember that the purpose of these is decoration. I’m not timber-framing. Still, I did prepare the mitered surface with thinned liquid hide glue before the normal (liquid hide glue) application.

For what it’s worth, I did try knocking them off after the glue dried, and they didn’t budge.

And so here’s the result, edges broken and ready to be painted (at least, I think I’m painting it):

Now I’m destined to overthink the paint. (I think it’s supposed to be white.)