14
Oct 18

Sliding dovetail postmortem

So looking at the pieces of scrap I was practicing on yesterday, I see that the power-cut dovetail has a consistent angle but the edges are anything but sharp and there’s a problem with blowout:

While the hand-cut version is messier but holding:

A bit more practice would clean that up. It’s slower, but it leaves you with all your fingers, which is a plus. The back end broke out because of short grain:

But you can see that the gaps aren’t as bad at the back end due to the angle being inconsistent. There are a few different hand methods to cut the joint – I was paring the angles with a chisel but there are more accurate methods. I guess I’m doing some more practice for a while and the doing this by hand.

Also, you can secure the joint a lot with a peg…

That will forgive a bit of sloppiness. It’s not exactly drawboring, but it’s better than nothing. Also, if I do a stopped dovetail, then drive the shelves into the sides from the front, the joint is hidden on the back by the stop and on the front by the shelf being a bit wider than the sides, which makes shaping easier.


13
Oct 18

Still have ten…

So after weeks of not getting to the shed at all because of work and feeling pretty guilty for that, I finally got out there for a few hours today. The next step in the project is the sliding dovetails – the main desk surface shelf has been cut to the right angle, the sides are both shaped, the top shelf and middle shelf are both ready to have the angles cut but I want to get the sliding dovetail for the desk surface done first. And since I’ve been away and am now rusty, out with a bit of beech scrap to try to cut sliding dovetails in for practice.

On go the layout lines, out comes a scrap to run the router along to cut out the female part of the dovetail, I hog out the main part of the waste with a straight cutter and then cut the dovetail edges with the dovetail cutter I bought for this (it’s my only good router bit) I cut the female part out and then checked the board that I hadn’t yet cut the male part of the dovetail into and the whole board went into the female part leaving a gap.

Right. One of *those* days, is it?

Do the whole thing again, this time being extra careful on the cut lines, hog out the central waste as before, set up for the first cut of the dovetail edges, turned on the router, started running it along the fence and while taking hold of the router base, stuck my finger into theĀ running router and caught the locking nut on the collet with the end of the finger. I think I missed the blade by about a centimeter, or as sane people measure it, way too fecking little.

Happily, nothing came off, bar perhaps a high pitched girly scream of panic, and I now have feeling back in the finger again, but I think it goes without saying that I downed tools at that point and went off for a few minutes to have a somewhat shaken cup of tea.

Have I mentioned lately that I dislike power tools somewhat and that routers scare the absolute living shit out of me?

Anyway, after a cup of tea and a change of shorts, I went back out and tried cutting the sliding dovetail by hand by cutting the male part of the dovetail first and marking it off against the edge of the board and then cut out the waste like it was a housing joint which I kindof can do, and then pared to the line for the dovetail – for the actual thing, yes, I’ll use the router, but I’m not touching that daemon-possessed finger eater for a day or two, okay?

Anyway, got the joint to work on the first go with the hand-cut approach, but obviously that includes the usual “doesn’t fit, pare the fecker” steps until it worked. So I think the design will probably have to be slightly adjusted to allow for blind panic and to hide the gap as much as possible by letting the shelves come out a bit to the sides to act as endcaps for the joint. I was seriously impressed with the strength of that joint against pulling out though, I thought it’d be a bit squidgier than it is. It’ll definitely do the job, assuming I cut it right.

And, obviously, don’t remove a finger or two in the process…