Trimming the tenon cheeks and shoulders was fairly straightforward. The hardest part was flipping the 200 lb slab every 5 minutes…
There were two issues. First, the tenon shoulders weren’t coplanar. In fact, they formed a kind of X. I doubt my collar jig was that bad, so I’m inclined to think there was a lot of flex in the circ saw, and probably exacerbated by the blade burning issue.
The second issue is that the tenon depth was uneven. That’s a layout problem.
It was probably too much to ask to get a perfectly cut tenon from a circular saw, anyways, so I’d recommend planning on trimming/squaring it up from the start.
Here’s the non-coplanar issue:
I have a track that clamps across a board and has a slide I can attach to my router. So I figured out the relevant offsets and carefully laid out a square line across the slab at the desired location. Because I need to do this operation on both sides, I extended the layout lines down the sides of the slab, too. Then I clamped the track on the line:
Set the plunge depth to a hair less than the shoulder depth. The tenon is already trimmed to width so I don’t want to touch that. I’ll use a chisel to trim off the little sliver I miss with the router.
The first trim:
A little bit of tearout in the middle where I attempted a climb cut. D’oh! And that’s the top :-(
I was very careful when I extended my layout lines across down the sides. I need to flip the slab and reset the track on the other side. I then had this idea that I could clamp squares in place to register the track against after the flip:
Surprisingly, that worked perfectly. I removed the track, carefully flipped the slab and gently reset the track. Looked like it lined up, so I went for it. Dead on. No pics, you’ll see the fit later.
The next step was to trim the tenons to depth. I have an adjustable edge guide jig I use with my router, and I started with that. I removed the adjustable part and attached a fixed-depth fence. Nothing special about that, just a piece of scrap plywood cut to the right width. It was set to just touch the router bit.
And here’s how it looks poised for action:
Set the plunge depth to half way, and take a pass:
Flip the slab, do the other side. The end cap fits perfectly, no need to undercut anything.
I got a start on fitting the vise hardware. That’ll be the next blog post.
-- Mark Kornell, Kornell Wood Design