Which is stronger?

[Tom Watson]

Ya know, Swing, like most joints, it prolly talks harder than it cuts.

I don't think it will slow you down any in production once you get through the Goldilocks process of, "Too Tight, Too Loose, "Just Right".

All new joints are a process until you get to the point of, "Fire For Effect".

I believe it would be a damned strong joint, with little extra time involved, once the jigging was perfected.

It sounds like you are trying to use a router.

I'm not big on round-shouldered joints, regardless of the gluing surface presented.

I'd use a morticer and be done with it.

I like the lock of the right angled shoulder, and with a joint that is not haunched, I would particularly look for some right angles in the joinery.

Just my opinion.

As always YMMV.

Regards,

Tom Watson

tjwatson1ATcomcastDOTnet (real email)

[Leuf]

Yeah, but.. it clamps to the sides of the rail right? So what difference does it make what angle the end is at, other than that if you don't want the mortice parallel to the sides it has to be able to compensate for the angle?

-Leuf

[fredfighter]

ISTR that those are called fox tenons.

[Swingman]

Very impressive, Todd ... and I appreciate your input. My gut feeling is that the "easiest to machine", which is also the most precise in this case, might mitigate any slight strength issues over a run of parts, particularly if the joints are pinned as planned.

Right now I'm in the process of "jigging up" for a prototype and still have a good deal of freedom in methodology.

Thanks again for taking the time to respond.

[Swingman]

I feel the same way, but wanted to explore something different for the angled and compound angled joints this time around. Most of the other joints, and there's a ton of them in the back and seat, will be cut with a morticer.

Been reading too many design tips lately. Seems like the current philosophy is to design first, then figure out the joinery after the design is cast in stone.

My first question when I see a piece done that way is "Yabbut, how long will it last" ... with FLW's falling down "Fallingwater" in mind.

Right now I've got a belt on, but I'm still looking for those suspenders ... looks like you've found a pair

[Swingman]

Good question. I've put some pictures up for you.

Go to the url below and scroll down to "Router Mortising Jigs" and you'll see the simple jig that allows you to do this:

me know if you have any questions.

[Lee Michaels]

"Swingman" wrote

OK Swingman, I have to make these remarks.

I have worked in various communication capacities and have had to evaluate marketing materials and corporate communications. I had to constantly fight the artsy fartsy graphic designers who can take any simple communication task and turn it into a psychedelic nightmare. I remember when a newsletter was a page or two of typewritten information that you could use.

Your website is a marvel in simplicity. Both in terms of design and communication. You use pictures to illustrate what you are talking about. You give short, concise messages with the pictures. And you do so in a warm, folksy manner that is such a refreshing alternative to the marketing centric styles of so many other websites.

And it chronicles a guy who has a simple, small shop. There is no big warehouse or commercial shop here. It gives information freely to ordinary folks who want to create or expand a home workshop. I have your website in my favorites list. And I recommend your site to others.

Just wanna say, good job sir. If more folks did such a good job as you with their website, the web would be much more enjoyable (and educational). It makes the whole putting together a shop thing more do-able. It is a pleasure to peruse your website.

Now I gotta go back to being my usual curmudgeon self.

Lee

[Michael Daly]

Civil eng (Structures) with one old prof that used to toss the textbook and point out the basics occasionally.

If it was an isotropic material, I might agree, but it's wood and the grain will dominate the behavior. Wood can exhibit significantly different strengths depending on orientation relative to grain.

How that joint will behave will depend on factors beyond just the wood or the orientation of the tenon. If the joint is glued with a seriously stiff and strong adhesive that prevents any motion in the joint, either will be strong. If the adhesive can flex, the shape and orientation of the tenon will affect the overall strength (given the grain). Since I've seen more joints fail due where no strong adhesive is used or the adhesive lets go, I'd tend to design ignoring the adhesive and then B is stronger. I wouldn't go with a tenon crossing grain lines significantly. If the tenon in the drawing is to scale, then the rail is thin on the periphery - Use B.

If the wood selected has crap grain, either A or B would be equally weak.

Mike

[Lew Hodgett]

You had one of those to huh?

Mine wasn't old, just a slave driver.

I still remember his tag line, "Gentlemen, get out your coolie hats, it's time to go to work."

Lew

[Swingman]

... and you sir, have to be one of the most intelligent folks on the planet! ;)

Thanks for the kind words ... I'll be blushing for the next week or two.

[Rod & Betty Jo]

As you should ...your one of the guys whom make the wReck a "must read" with my morning coffee.....Thanks Rod

[Tom Watson]

I've always been a fan of form following function. I have enough ego that I would not like to see a difficult to achieve joint hidden.

I don't know what your constraints are on the design level, so I responded with what I thought would be a strong joint for the given conditions.

If I had my way, I'd show the wedged tenon, rather than create a hidden version. I never really liked the idea of "Secret Mitered Dovetails" for the same reason.

I didn't like the "A" version because it violated my sense of joinery, which includes the notion of eliminating as much short grain as possible.

I'm conversant with the arguments for loose tenons but there is something about them that sticks in my craw. I'd rather see an honest tenon on that rail or stretcher, with an exposed wedged tenon. It seems more craftsmanlike to me.

Some smart fella said something along the lines of, "Joinery is the beginning of ornament".

All I can say is, "Amen".

Regards,

Tom Watson

tjwatson1ATcomcastDOTnet (real email)

[Swingman]

The saga continues:

"B" has always been my preference, particularly once I found a source for carbide end mills of sufficient length that could be used in a router.

... nonetheless, the JDS Multi-Router is looking more attractive all the time.