Craftsmanship in Wood

Looking forward to seeing this keta connection joint Derek! It's the most ideal method for this framing situation, IMO.

Thanks Chris,
I received the images via email and have perused them. It looks like there is easily enough information supplied within to complete the joint cut out.

It's interesting that one side of the Keta connection is not supported directly by the Tsuka underneath the intersection, but is only by the relatively thin tenons, does that limit the total load that this construction can bear?

I was also wondering if this roof structure pertains to the structural roof that sits above the decorative roof, or is this merely another example of a decorative roof, similar in function to the last model?

Cut out to follow, some challenges in keeping dimensions accurate over long tenons and mortices I suspect.

Derek

The full-sized version of this joint can incorporate a stub tenon for additional support on the 2-piece keta side, however bear in mind (pun intended) that the hip rafter travels right through there, and is primarily supported by the 1-piece keta, so that member is carrying most of the load. If the roof load is expected to be heavy (i.e., snow load, heavy tile roof), then a corbel can be fitted under the connection, in line with the 2-piece keta. I'll send you an image of the full size one so you can see the detail differences.

This model is being done as a single-layer roof, and will have taller rafter sections than you would see with the decorative roof/hidden roof system.

I promise things are actually happening...

I started with the morticed piece. I drilled and pared the mortices first: After I was happy the mortices went squarely through the main Keta member along their whole length, I started the cheek recesses that take the cross Keta, first marking out the depth of the mitred abutments: Then cut out ensued:
The mitres are cut well shy of the line at this stage. Some carelessness with the chisel blowing out some wood near one of the mortices mars an otherwise nice surface.

More to come over the next week.

Both cheeks of the main Keta piece cut now, both still with bucket loads of room to manoeuvre on the mitred abutments:

The trenches to receive the cross piece tenons have been mostly cut - still a couple of mm shy of final depth. It's a stopped groove at the moment because I haven't cut this piece to length yet:

Coming along cleanly

Activity has stalled for a couple of days awaiting a new tool - I will share photos with you all when it arrives.

A hair more needs to come off the thickness of the tenons before this joint is ready for trial fitting. Then the wedging pins and this should be complete.

First trial fitting and despite measured dimensions being satisfactory, there is still enormous friction inserting the tenoned piece. Here shown pretty close to fully inserted: And here as closed as it can be without fine tuning of the mitred abutments: Tenons passing through the other side: And here with the morticed piece. This was as close as I dared close up the joint for fear of needing excessive force to get it apart: Still a little more needs to come off the tenons such that the pieces will assemble with only reasonable pressure.