mitered corner lap joint

Furniture making techniques with solid wood.
jamie shard
Raw Log Import
Posts: 19
Joined: Thu Dec 04, 2014 8:58 am

mitered corner lap joint

Sat Jul 25, 2015 7:59 am

It seems like I'm doing more designing than making these days, but I'm also restoring a bunch of vintage woodworking machinery so I see some glorious building days ahead... In any case, I've been trying to understand the joint Chris used in the Vanity series and I have a couple questions.

Here's my sketch-up of the joint, playing with different amounts of overlap on the top and bottom:
mitered corner show side.png
mitered corner show side.png (9.54 KiB) Viewed 866 times
Here's the back side:
mitered corner back side.png
mitered corner back side.png (11.94 KiB) Viewed 866 times
I think these open sections on the back are simply part of the joint - but maybe I'm missing something obvious?

I suppose the mitered cuts could be done in a way (slightly more than 45 degrees) so that all the lines would hit that back corner, leaving no open sections, but that seems like a lot of work. I suspect that a 45 degree miter is used and if the back surface needs to be flush, then the part can be made wide and then the back edge ripped to dimension.

Does the above seem correct?
User avatar
Chris Hall
Site Admin
Contact:
Location: Greenfield, Massachusetts
Posts: 2385
Joined: Mon Nov 22, 2010 12:46 pm

Re: mitered corner lap joint

Sat Jul 25, 2015 12:21 pm

Hah! Where were you for the last joinery study project? We covered a very similar joint...

Yes, for a 90˚ corner, a 45˚ miter line would be the usual choice. Your miter on the underside is offset, which causes part of the problem on the inside edge - the rest is that you ran the tongues right through instead of stopped.
jamie shard
Raw Log Import
Posts: 19
Joined: Thu Dec 04, 2014 8:58 am

Re: mitered corner lap joint

Sat Jul 25, 2015 8:06 pm

Thanks for the confirmation. This is such a neat joint.

With the right jigging, I think it might lend itself to a table saw construction, e.g., 1/8" blade could make all the cuts for a make a 7/8" thick frame. In theory, it could be pretty fast if all of the miters/laps were through cuts. Hmm...
User avatar
RLSIII
Raw Log Import
Posts: 40
Joined: Wed Nov 26, 2014 9:47 pm

Re: mitered corner lap joint

Sat Jul 25, 2015 8:29 pm

I believe you will find that hand tools will dominate the cutout in this joint and most of its variants. I like the idea of the table saw jig, but fear of will never attain the necessary tolerances to execute this joint properly. Also 7/8 " ? Thats alot going on for such a small area, I've found even 1.5" material to be tricky with mitered box joint variants ive tried since tackling the model joint. Keep playing with the 3d model and look for the post from Chris's blog detailing the shachi sen. I think unless I'm mis interpreting the model you posted you overlooked one or two details about the trenches that will prove helpful come fitment of the wedges. Keep up the good work!
Rob S
jamie shard
Raw Log Import
Posts: 19
Joined: Thu Dec 04, 2014 8:58 am

Re: mitered corner lap joint

Sat Jul 25, 2015 9:33 pm

ah yes, time to crack open volume 3! :)
User avatar
Chris Hall
Site Admin
Contact:
Location: Greenfield, Massachusetts
Posts: 2385
Joined: Mon Nov 22, 2010 12:46 pm

Re: mitered corner lap joint

Sat Jul 25, 2015 9:41 pm

It's not covered in Volume III, as that is about splicing joints, not angled joints...
jamie shard
Raw Log Import
Posts: 19
Joined: Thu Dec 04, 2014 8:58 am

Re: mitered corner lap joint

Sun Jul 26, 2015 7:39 am

Hmm, but is it something to do with compound layout to make the tapered shachi sen fit securely (which was touched on in volume 3 in a splicing application)?
User avatar
Chris Hall
Site Admin
Contact:
Location: Greenfield, Massachusetts
Posts: 2385
Joined: Mon Nov 22, 2010 12:46 pm

Re: mitered corner lap joint

Sun Jul 26, 2015 8:49 am

Yes, that section on shachi sen in Volume III touches on the same topic, however it is a little more complicated with the right-angled joint due to the fact that the pin enters at a 45˚ angle in plan.
jamie shard
Raw Log Import
Posts: 19
Joined: Thu Dec 04, 2014 8:58 am

Re: mitered corner lap joint

Sun Jul 26, 2015 9:36 am

Ugh, where was I during the last joinery project?! :D

I'm going to try figuring it out, but I can already appreciate what I'm up against and may ask for pointers...

Return to “Furniture”

Who is online

Users browsing this forum: No registered users and 1 guest