When doing mortise and tenon joints I’ve tried several ways from routering to dado cutting the tenons.
The easiest is using the table saw and having build a tenoning jig this is now the preferred method. Cheek cuts are clean and well cut. Then placing the rail up to a stop block and cutting the shoulders gives a cut that needs touch up with a shoulder plane. Cheek shoulders do not align with edge shoulders which leaves a slightly open joint when tenon is placed into the mortise.
Am I expecting too much from this approach as videos and literature I’ve seen show a perfect fit right from the saw?
Maybe my table saw or the saw blade?
Replies
I don't think your stop block is perpendicular to the table surface. When you make the 4 required shoulder cuts you have the surface or edge of the board laying flat on the table surface, this makes the end of the board touch the stop block high or lower. A tapered or non-perpendicular stop block will result in your problem.
Don
Ah yes...Thanks for your advise this seems to have solved the problem.
Is it possible for you to tell us what you did to correct the problem? Could be good info. for others.
Regards,Bob @ Kidderville Acres
A Woodworkers mind should be the sharpest tool in the shop!
This post is to KiddervilleAcres and to all who have chipped in with advise. Registration of the rail to a perpendicular stop block clamped to my table saw sled and with the left face of this block checked for 90 degree squareness has solved the problem.
Mike Hennessy's technique for cutting tenons is interesting and I will definitely try this method. This combined with The Complete Mortise and Tenon Joint video on FWW by Gary Rogowski may be the answer?
Pil
Toronto ON
Wow! I was right about your problem. Glad it all worked out for you.
pil,
That's great, glad it al lworked out for ye.
Good one Don.
Regards,Bob @ Kidderville Acres
A Woodworkers mind should be the sharpest tool in the shop!
Thanks for taking the time with your helpful tip.
Pil,
I too have fought this shoulder problem when cutting tenons. I eliminated the stop block and use the fence with the miter gauge...checking to be sure everything was 90 degrees, etc. The problem did not go away entirely. I suspect grip pressure may play a role in the outcome. One outcome that surprised me was when I recycled a few pieces of wood that had been previously prepared for french polishing..the stock was extra flat having gone through the final preparation process. Perhaps i held the stock differently, I don't know, but those tenons were a definite cut above anything previous. So my obvious point is maybe it's our stock prep that needs additional attention?
Careful now. It is a dangerous practise to use the fence itself as the stop block. A slight twist and POW.
If you are having problems with the wood shifting on the miter gauge after leaving a stop block a little sandpaper glued to the face of gauge helps a lot.
46984.8 in reply to 46984.6
Careful now. It is a dangerous practise to use the fence itself as the stop block. A slight twist and POW.
That is some good advice Steve. The instant I read that use of the fence, I said .. watch out it will happen with a bang.
d
Steve,I'm not interested in convincing anyone of my method, I mention it to show my willingness to try almost anything to eliminate this issue. Conventional wisdom is this is dangerous. Personally, I don't see it. Most of the rip cuts I make seam more risky all things considered.
I have to agree with Don, as I can't think of any other way this could happen. I have cut tenons different ways band saw, hand saw, the tenon jig on the table saw works the best for me. Then I cut the shoulders with a crosscut sled with a stop block and the results should come out perfect. If your using a miter gauge make sure it fits the T slot properly. Good luck.
Mike
Miter gauge is not 90 degrees. You are cutting slight angles which is why the shoulders don’t match when using one side then the other as the reference surface against the miter gauge.
Here's how I do it.
46629.4
If your shoulders are not aligning, somethings not set up square.
Mike Hennessy
Pittsburgh, PA
Everything fits, until you put glue on it.
If your miter slot isn't exactly parallel to the blade it will cause the problem you are describing.
John White
Shop Manager for FWW Magazine, 1998-2007
With all due respect to Mr. White - this doesn’t seem to be the case. A blade that is not parallel to the miter slot will bind and cause a wide kerf but the corners will be square (and thus equal if the board is flipped over and cut again as with a tenon shoulder. ) The proof is to draw it. Note the attachment (proof 1) - blade is clearly not parallel to miter slot. Note the path of the cut. As long as the miter gauge is square the path of the board will result in a square cut - burned but square. The main cause of unequal shoulders is an out-of-square miter gauge. Slippage during the cut can play a role. If the unequal shoulders are still square then I agree an out of parallel fence could play a role because, if the end of the board is square, where you register the board first against the fence will effect the length of the tenon. I would never use the fence for this but I do use a block clamped to the fence for the registration of the cut. See proof 2.
John White said: "If your miter slot isn't exactly parallel to the blade it will cause the problem you are describing."
Or if there's play between the slot and the guide bar, or if the miter guage is off square, or if the wood is not clamped tightly to the guage and it moves a bit during the cut.
Have you tested to see if your saw is cutting perfectly square crosscuts otherwise? You should probably start there in your quest. If something is off (and I'm betting something is), you're on a fool's errand until you get it "squared away". (Groan!) Take a nice wide scrap, about 3' long, and crosscut it. Flip one of the resulting pieces and tightly mate the cut ends. Test the 3' edge to see if it makes a perfectly straight line. If not, you have some adjusting to do.
Personally, I hate using my miter guage. (To be fair, it's only a piece of carp that came with the cheapo saw. But I still hate using it.) I always opt for the RAS if possible. If I didn't have a RAS, I'd surely have a sliding crosscut jig (fixture?) for the TS. I'd suggest you start with that and see if it doesn't improve things for ya.
As an aside -- regarding using the fence while crosscutting, in general I agree with those who say it's a bad idea. Better to use a spacer block that ends before the cutting starts. That said, since you're only cutting off tenon cheek waste cuts and not through-cut, it's probably not TOO dangerous. (I assume you've learned to duck as the saw ejects the cutoffs!?)
Mike Hennessy
Pittsburgh, PA
Everything fits, until you put glue on it.
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