More than you ever wanted to know about Mortise & Tenon

The mortise and tenon joint is a must have in your techniques arsenal - if you're going to make solid wood furniture. It's not that difficult a joint to make - IF you pay attention and use a decent technique/method. And if you understand what does what, why and how, well all the better.
So here's the url to a bunch of stuff I put together on M&T. Hopefully it'll save someone some grief, or get someone to try this great joint.
http://web.hypersurf.com/~charlie2/MT/MTPrimer0.html
As usual, comments, suggestions, constructive criticism will be appreciated. I'll revise things if needed.
charlie b
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Actually a good read... the pictures are helpful in the process of understanding.
Far too much stuff gets put to print, but with no pictures the story remains "cloudy".
How do you do your graphics ???
Good job.
charlie b wrote:

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Pat Barber wrote:

Some people are text oriented - read it / under stand it. Some folks are visual - show me a good illustration and I get it. Some need to hear it to get it. Then there are folks like me - let me read it, look at the illustrations and try it a few times.
I hate it when magazines, etc. don't put the text near the accompanying picture or illustration. I particularly hate the wood magazine that puts the pictures, each numbered, side by side and down three or four rows then bury the refence number in the descriptive text, sometimes on the previous page - or two.

Hence A Picture Is Worth A Thousand Words. See It - Do It makes a lot more sense than Read It, Read It Again, Try It, Go Back And Read It Again, ...

The line drawings are done in an old Aldus Corporation program called SuperPaint v 3.5, last update in '93. Adobe bought Aldus and shelved their products which competed with Adobe products - in this case Illustrator. Oddly enough - Adobe Illustrator will read the SuperPaint file format.
For an object oriented graphics program that cost maybe $70 in '93, it's pretty powerful. Not a true CAD program but it does let you do scaled drawings.
The "3-D" stuff is actually all drawn ala drafting - with shading, cross hatching etc. done by creating polygons of up to a hundred or so vertices.
By the time I've drawn an idea and two or three variations, I have a much better understand what I'm trying to illustrate. Sort of like trying to program a computer to do a specific task. By the time you get the computer to "understand" you're pretty close to being an expert on the subject.

Thanks. If it helps someone succeed at making a mortise and tenon joint sooner, or gets someone to try it - I'll be a happy camper.
Again - if something isn't clear, or missing, or could be illustrated better - please e-mail your comments, suggestions, etc.. and I'll work on improving the information.
charlie b
nowback to using the Akeda DT jig to make a DT box to hold all the pin guides, tail guides, half pin guides, router guide bushings, a few bits, etc.
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Looks good - lots of info about a very important joint. One thing that might be a typo (or maybe I'm not understanding it) - from the "How Tight Is Too Tight?" page, 2nd paragraph: "After you fit the tenon into the mortise you should be able to turn the piece so the mortise can fall out. " Do you mean that if you turn over the dry-fit pieces, the tenon should remain in the mortise? You do say this in the next paragraph, but I still don't see exactly what you're trying to say. If this isn't a typo, I don't understand how a mortise could fall out in the first place. On the same page, another thing I've done on a tenon that's too tight is to mark the cheek with a pencil, and see where it rubs off inside the mortise, and pare those areas.
Thanks for taking the time to compile and share all this info! Andy
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Andy wrote:

Good - just the type of thing I was hoping for - blind spot on the author's part. Check the revised page and see if The Gravity Test illustration gets the idea I was shooting for better. And I hope you don't mind that I added your pencil the tenon, slip it in the mortise and look for black marks in the mortise sides.
http://web.hypersurf.com/~charlie2/MT/MTPrimer13.html

No problem.
charlie b
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That was quick! Much better - looks great. Let me know if you're doing another book sometime and want a proofreader. One possible exception to the gravity test I just thought of, though - I would think the test is good for most picture frames, smallish cabinet face frames, most chairs, etc., and I guess that covers most projects that most woodworkers do. However, it might not apply to much larger pieces. (I completed a bed last year, and each leg and rail weighed probably 10-15 lbs, so if the tenons stuck in the mortises when held up in the air, they probably would have been way too tight. If they were cut with a smooth friction fit, and held in the air, I think they would have pulled right out). I'd be curious to figure out what the weight ranges are that would be appropriate for that test, and whether it would vary by type of wood, smoothness of tenons, size of tenons, etc... I'm sure it doesn't really matter, and I agree that it's a good rule of thumb regardless.

Not at all! Hope it's helpful to someone.
I've actually been looking for the new URL for your website recently - I'm thinking about attempting my first hand-cut dovetails sometime soon, and ran across some outdated links to your pages in the archives here. Glad to see your site's still up and running, and I'm looking forward to looking through your dovetail page. I'll let you know if I see anything that isn't clear.
Thanks again, Andy
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<snip>
Great job, as usual, Charlie.
Of particular value is the page on reference faces and edges--should probably be duplicated in a discussion of ANY joinery.
Following are some suggestions, edits, nit-picks:
http://web.hypersurf.com/~charlie2/MT/MTprimer5.html The perspective drawings don't appear to correspond accurately to the plan drawings. In particular, all of the tenons on the "other end" of the pieces in the perspective drawings appear to have four shoulders.
http://web.hypersurf.com/~charlie2/MT/MTprimer10c.html I think the text description in the last paragraph has the two cases reversed. The drawing is what I would expect, and maybe my problem with the text is based on my lack of knowledge of a tite-mark. But it looks like the two flat sides are facing OUT when marking the mortise and IN when marking the tenon.
http://web.hypersurf.com/~charlie2/MT/MTPrimer11.html First and second paragraphs: While it makes sense that the faces of the mortise be paired, I think you mean "pared" here.<g>
http://web.hypersurf.com/~charlie2/MT/MTprimer12b.html caption of fourth picture, typo on "horizontal"
--
Alex -- Replace "nospam" with "mail" to reply by email. Checked infrequently.

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alexy:
Thanks for taking the time to give this stuff a good going over. I look at it and see what I want to see rather than what's actually there - hence the desirability of more sets of eyes looking for holes, ambiguities, flat out wrong information, etc.. Guess that's why publshers have editors.
Went over the pages you identified and I think I corrected everything and redid the page 10c
http://web.hypersurf.com/~charlie2/MT/MTprimer10c.html
Do the revision makes more sense now?
Any one else see any problems or have questions this stuff should probably try and answer?
charlie b
alexy wrote:

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charlie b, I stand in awe of the prodigious effort that you have lavished on your web page. You have produced a work to be proud of. Joe G charlie b wrote:

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Your website is amazing. You should publish a book, or at maybe a PDF of your website for people to download and have in their shop for refrence.
I would be more than happy to give you a hand doing that if you were intersted.
Todd
charlie b wrote:

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