Replies

1. 
   scooter1 | Nov 09, 2005 10:27pm | #1

   This is what I do--there are several ways to address this issue:

   First, it may be easier to angle the mortises. I have built a "U" shaped plywood box to hold table legs precisely. One side of the "U" is higher than the other, so the router is held at an angle.

   Second, there are a couple ways to angle a tenon. I have used the table saw and a tenoning jig, but the process makes it dificult to cut the shoulders of the tenon.

   Third, if this is only a tenon or two, consider making full size shop drawings and just laying out the tenon and cutting it with a hand saw. Not a big deal.

   Fourth, is a shop made tenoning jig for a router. This is a half day project. I got mine from Taunton's "Making Chairs", I forget the author, but it might be Jeff Miller. This is a "T" shaped jig, that holds the tenon at 90 degrees to a plate on top. The plate on top has 4x3 window in which the router bit rides. On top of this plate is a second moveable piece of wood with a similar window, but the window is bisected by a quarter inch or three eighths inch of metal or maple. This strip acts as a template or curb to either your flush trim bit or guide collar. The top bisected window has two strips of 3/4" wood running from the back to the front which sit on two 3/4" dados cut into the "T", so that this moveable plate moves in and out so that the maple strip is centered on your tenon.

   The tenon is cut with either a flush trim bit or a guide bushing. You'll need to trim the shoulders of the tenon with a handsaw. The tenon is clamped to the verticle part of the "T" with regular clamps and is held at 90 degrees by a fence. The top of the "T" is also at 90 degrees so you have a nice square tenon.

   I cut angled tenons by placing a wedge under the tenon to angle it out toward the user. Usually the angle is no more than 4-10 degrees. I take that angle off my plans or use a Bosch Angle Finder. The whole mess is clamped to the verticle portion of the "T", with another angled cutoff on top of the tenon, so it is parallel to the verticle membmer and square to the plate for clamping ease. Double stick tapes helps secure the whole mess.

   The book has a complete plan for the jig.

   You might try Pat Warners site, too, he is the routerman. I like Jeff Miller's jig better.

   Fifth, consider buying a Trend jig, a metal version of the above jig. I think the cost is around $300. It is made in the UK.

   Sixth, consider the Leigh FMT jig, but at a cost of $800, it is not cheap. This cuts the shoulders as well as the cheeks.

   Seventh, you can make a horizontal routing jig using an el cheapo fixed plate router (and stupid Sears router will do) and some plywood. There is a design in a FWW if you are interested. To angle the tenon, just insert a wedge under the tenon when routing it.

   Others may have additional ideas. Let me know if you need more help.

   Regards,

   Scooter

   "I may be drunk, but you're crazy, and I'll be sober tomorrow." WC Fields, "Its a Gift" 1934

1. 
   NumberNine | Nov 10, 2005 06:22am | #3

   Great suggestions, The Pat Warner one on his site looks like a winner but I'll check out Jeff's too. I'm tied to making a jig as it's part of a furniture school project so simpler/ quicker means are out the window!

2. 
   WillGeorge | Nov 11, 2005 02:37am | #4

   First, it may be easier to angle the mortises. For what it is worth.. I agree. In my humble opinion cutting the tenon on a angle weakens the stick...But I could be wrong! But not usually!

1. 
   Patto | Nov 11, 2005 05:48am | #5

   Will,

   I looked at this serously for my last project and came to a couple of conclusions.

   - I am not good enough to line up a mortice at other than 90* efficiently - and even thats occaisionally out

   -As long as a 'reasonable' proportion of the grain goes all the way along the tennon then the chances are it will not be the part that fails.

   having said that, it took a while to work out how to lay out and cut the angled tennons acureately. I used a square and a plastic drafting square to lay out the cheeks. I then cut all of the cheeks first, leaving the shoulders intact. I cut two of the shoulders so that the layout lines were intact and pared the cheeks to the lines, and then cut and finished the last two shoulders.

   Dave

2. 
   mudman | Nov 10, 2005 05:31am | #2

   On my last job I had to make tennons on curved pieces and after fiddling with different jigs I just laid out all the cuts and roughed it on the band saw then trimmed with hand tools. If you are only making 4 of these you will probably spend a lot more time setting up jigs and supports than if you just cut it by hand. And believe me any time I can use a tool to speed up the process I will!

   Mike

3. 
   Garry | Nov 14, 2005 10:13pm | #6

   Although in the photo below I am not using the jig for angled tenons, it can easily be used for this purpose. I made this in about an hour and it has had many uses.

   Garry

   View Image

   http://www.superwoodworks.com

1. 
   NumberNine | Nov 15, 2005 05:26am | #7

   Thanks for the replies, I've now got a good idea of what I should be aiming for. I might even go for some perspex on the top to help me line cuts up.

1. 
   74extiger | Nov 15, 2005 06:19am | #8

   You might want to consider the WoodRat. I bought mine in April. If you haven't seen it, the machine works using a router sort of in the fashion of a CNC. It is incredible for any kind of joinery. But, expect to pay about $1300 when you load up on the bits, tooling and accessories. Even has a digital read out and laser guide, if you're intrigued by techno stuff. Invest $6 in the the demo DVD before you buy something like a Leigh. It's different.Gary Curtis
   Los Angeles (moving to Trinity County, Calif)