Bird mouth joint

[algale]

How about one of these........

[ATTACH]22345[/ATTACH]

It will need to be darn long! This joint is used to rip the long edge of board, typically to make a mast for a boat.

[BuckeyeDennis]

Birdsmouth joints are used in wooden masts all the time, at least used to be when there were more wooden masts. There's another way to do it though. The way shown works because it is an octagon. 360/8 sides= 45 degrees.

This way works for all numbers of sides:

1) Divide 360 by the number of sides, lets say six = 60 degrees.
2) Set your saw to 60 deg and run the board through on edge for the first cut and then flat on the table for the second cut on the same edge. This will give you a 90 deg angled notch in the edge of the board and it will be canted at 60 degrees.
3) Run all six pieces and assemble. A long piece of bungee wrapped around and around works really well as a clamp.

You can taper the pieces first if you want and you aren't limited in board thickness like you are with the expensive router bits. I made some four foot, six inch diameter columns for my living room this way then turned them on the lathe. It is a great joint. ....... but then I think Harbor Freight is a great joint.

Paul M

Whoa .. did you say that your living-room columns are 4.5 feet in diameter?!!!

Or is that 4' long and 6" in diameter? I saved a copy of your 10ER restoration photo for personal inspiration, so I could be convinced either way!

[shipwright]

[quote="BuckeyeDennis"]Whoa .. did you say that your living-room columns are 4.5 feet in diameter?!!!

Or is that 4' long and 6" in diameter? I saved a copy of your 10ER restoration photo for personal inspiration, so I could be convinced either way! ]

Sorry, it would be the latter.

Paul M

[JPG]

[quote="BuckeyeDennis"]Whoa .. did you say that your living-room columns are 4.5 feet in diameter?!!!

Or is that 4' long and 6" in diameter? I saved a copy of your 10ER restoration photo for personal inspiration, so I could be convinced either way! ]

Dennis: There is a purpose to the comma between four foot and six inch.

[BuckeyeDennis]

Is it a possibility to set up the router, tilt the table to the appropriate angle and rout the bird's mouth? I've not done it nor tried that setup, but just brain storming ideas.

It seems to me that should work. Set up the SS in vertical mode, and use the table tilt instead of those expensive bird's mouth bits. Put the rip fence at the appropriate distance "downhill" to guide the workpiece. I would expect that you could then use either a straight router bit, or a shaper "jointer" bit, to make the cut. The quill and table "height" adjustments would enable you to fine-tune the cut.

[JPG]

It seems to me that should work. Set up the SS in vertical mode, and use the table tilt instead of those expensive bird's mouth bits. Put the rip fence at the appropriate distance "downhill" to guide the workpiece. I would expect that you could then use either a straight router bit, or a shaper "jointer" bit, to make the cut. The quill and table "height" adjustments would enable you to fine-tune the cut.

I agree, but would use the saw instead.

If 'surface finish' is important, a final pass with this router setup would work(or a very good saw blade).

[BuckeyeDennis]

[quote="JPG40504"]I agree, but would use the saw instead.]

You are a braver man than I!

Although I might be tempted to take the little saw blade out of the biscuit attachment and use it. To me, the small saw blade unguarded in vertical mode would be a lot less scary than the big one.

So now, I'm wondering if you could remove the plunger piece from the biscuit attachment, keep the rest in place as a blade guard, and still get enough depth of cut.

Edit: Come to think of it, I suppose that the "lower" saw guard could still be attached with the big blade (becoming a rear guard), if you can lock back the spring-loaded piece that the table normally pushes down. I'm going from memory here -- my SS is at home, and I am not.

[JPG]

You are a braver man than I!

Although I might be tempted to take the little saw blade out of the biscuit attachment and use it. To me, the small saw blade unguarded in vertical mode would be a lot less scary than the big one.

So now, I'm wondering if you could remove the plunger piece from the biscuit attachment, keep the rest in place as a blade guard, and still get enough depth of cut.

Edit: Come to think of it, I suppose that the "lower" saw guard could still be attached with the big blade (becoming a rear guard), if you can lock back the spring-loaded piece that the table normally pushes down. I'm going from memory here -- my SS is at home, and I am not.

Who said the words saw and vertical in the same sentence?

The router method used drill press mode. The saw method does not.

Quoting Shipwright above:

"1) Divide 360 by the number of sides, lets say six = 60 degrees.
2) Set your saw to 60 deg and run the board through on edge for the first cut and then flat on the table for the second cut on the same edge. This will give you a 90 deg angled notch in the edge of the board and it will be canted at 60 degrees.
3) Run all six pieces and assemble. A long piece of bungee wrapped around and around works really well as a clamp."

[dusty]

At first, I thought this was a simple task even with the tilted table of the Mark V. I no longer think so. Oh yes, it is simple but it is also hazardous. There was a time but no more. Not without a jig.

This is one job done more safely and probably more accurately on a table saw with a tilting arbor.

I am working on the concept of a jig to do this using a dado blade. If I work it out, I post pictures. No pictures means no success (that's the same as "failure").

JPG: Have you done what you detailed in post #17? If yes, please post a picture of the setup for the 60° cut.

[algale]

At first, I thought this was a simple task even with the tilted table of the Mark V. I no longer think so. Oh yes, it is simple but it is also hazardous. There was a time but no more. Not without a jig.

This is one job done more safely and probably more accurately on a table saw with a tilting arbor.

I am working on the concept of a jig to do this using a dado blade. If I work it out, I post pictures. No pictures means no success (that's the same as "failure").

JPG: Have you done what you detailed in post #17? If yes, please post a picture of the setup for the 60° cut.

Hazardous because of kickback from the wedge trapped between the blade and fence or something else?