compound angle dovetails?

[Jim Koepke]

I just bought the Stanley rear locking type before this project and really like the rear lock mechanism and how tight it locks up.

Is this what you mean by "rear locking type" bevel gauge?

Koepke Bevel Gauge.jpg

Patrick Leach considers those (Stanley #18) the best bevel gauges made.

jtk

[Warren Mickley]

Yes. We lay out the slanted cuts for the ends of the sides with a bevel gauge and a knife. Then we cut with a back saw about 1/32 from the lines (this cut will be slanted a little bit). Then we put it in the vise and plane to the knife lines. It is not much more difficult than planing square. Because we are planing at a slight angle, we don't have to worry about breaking out at the end as we would with a square cut. Then, since the angle is correct, you can use your marking gauge to lay out the lines for the dovetails.

Using a layout block as I described earlier not only helps set up the bevel gauge, but helps us visualize the joinery.

[Ben Ellenberger]

Warren, do you need to set the marking gauge thicker than the joining piece to get the pins/tails to come out right? I’ve been trying to think that through, and it isn’t obvious to me that the marking gauge would be aligned in the correct plane to be able to measure directly off the joining piece.

I may have to go play around with some scraps soon and think about this some more.

[Michael J Evans]

Is this what you mean by "rear locking type" bevel gauge?

Koepke Bevel Gauge.jpg

Patrick Leach considers those (Stanley #18) the best bevel gauges made.

jtk

Jim
Yes that is what I mean by rear locking.

[Warren Mickley]

Warren, do you need to set the marking gauge thicker than the joining piece to get the pins/tails to come out right? I’ve been trying to think that through, and it isn’t obvious to me that the marking gauge would be aligned in the correct plane to be able to measure directly off the joining piece.

I may have to go play around with some scraps soon and think about this some more.

The point of getting the angle right on the end grain is so that you can use the marking gauge to mark out just the way you do for square boxes. If you make a sample block as I mentioned above you can not only use it to set your bevel gauge, you can use it to help visualize the joint.

[Michael J Evans]

Warren

When marking out the end grain to get it planed to the correct angles, would you just use the square on the edge bevel and use a knife to mark from corner edge to face?
I am asking this, because I'm trying to figure out how I could do this very accurately to keep each piece exact length.

Or would you measure in very slightly and then do your marking?

[Warren Mickley]

Here is an example of a 15 degree slope. Do the bottom and top slopes last. First mark out the length with small knife cuts at the top corners. Then using a bevel gauge mark the front sides of the piece. (75.5 degrees). Then mark the top and bottom with the 93.8 bevel gauge. Mark the back with the 75.5 . Saw these a little bit from the lines and then plane to the lines. Last plane the top and bottom at 75 degrees.

A test block will give you the angles and help visualize. Here is a test block (beveled on two sides) showing 75 degrees, used for top and bottom
bevel 1.jpg

Here is the bevel for marking out the ends of the tray sides 75.5 degrees:
bevel2.jpg

Here is the bevel set for the angle from the face to the ends 93.8 degrees;
bevel3.jpg

[Michael J Evans]

I must be missing something but is the end grain and then one edge bevelled in those pictures?

Where did you get those angle measurement's / how did you figure them out? In my case I wanted a 20* slope, so I know the edges are 20* but then how do I figure what to set my T-bevel for the end grain compound cut based upon that?

You've likely said it about 20 times already, my mind is just having a hard time processing it.

[Dean Arthur]

Michael,

I had run across the Bob Rozaieski video for angled dovetails previously as well and though he seems successful with it, for my use it seemed needlessly complicated.

These instructions for a moravian footstool are a better approach for angled dovetails in my opinion. Best of luck!

[Warren Mickley]

I must be missing something but is the end grain and then one edge bevelled in those pictures?

Where did you get those angle measurement's / how did you figure them out? In my case I wanted a 20* slope, so I know the edges are 20* but then how do I figure what to set my T-bevel for the end grain compound cut based upon that?

You've likely said it about 20 times already, my mind is just having a hard time processing it.

The block I made, as described earlier, has a 15 degree slope on one edge and one end grain. I was able to take the bevel gauge settings straight from the block. I then measured those angles and checked them with the angle program posted by Richard Line, #6 in this thread.

Using the angle program for a 20 degree slope (70 degrees in the program), I get 71.2 degrees for the angle between the long edge and the end edge of a tray side, and 96.7 degrees (slightly more than 90) for the angle from the face to the endgrain. I recommend building a sample block because it is easier to set the bevel from the block than from a protractor. It also helps with visualization.

[Warren Mickley]

Michael,

I had run across the Bob Rozaieski video for angled dovetails previously as well and though he seems successful with it, for my use it seemed needlessly complicated.

These instructions for a moravian footstool are a better approach for angled dovetails in my opinion. Best of luck!

The Moravian footstool has angled dovetails, but they are not a compound angle like a slope sided tray. The dovetails in the footstool are much simpler to make than a tray.

[Michael J Evans]

The block I made, as described earlier, has a 15 degree slope on one edge and one end grain. I was able to take the bevel gauge settings straight from the block. I then measured those angles and checked them with the angle program posted by Richard Line, #6 in this thread.

Using the angle program for a 20 degree slope (70 degrees in the program), I get 71.2 degrees for the angle between the long edge and the end edge of a tray side, and 96.7 degrees (slightly more than 90) for the angle from the face to the endgrain. I recommend building a sample block because it is easier to set the bevel from the block than from a protractor. It also helps with visualization.

Ahh okay.
I was thinking I had to do some crazy math to pre calculate of it.

[Ben Ellenberger]

This thread got me motivated to make a joint and take some pictures. Putting the steps down in writing will help me get the process straight in my mind, and hopefully someone else will find this useful too. I’ve only made two little boxes with compound angle dovetails, so I’m far from an expert at this.

I made two blocks at the angles I wanted the sides to splay out at. I used those blocks to set a bevel gauge and mark the bevel I wanted on the bottom of each piece. Then I planed the the bottom of each piece to the correct angle. I could use the angle blocks to prop each piece up and a square to hold the two pieces square to each other. My reference face is the inside face of each piece and my reference edge is the bottom edge of each piece. I didn’t plane the top edge of either piece, and I only rough cut them longer than they need to be.

EFD6F617-D4AF-4E02-BB1C-4F263DE83696.jpg

I planed the side of a pencil flat so I could hold it against the inside face of each piece and project the angle onto the end of the other piece. I did that with each piece and used a bevel gauge referenced on the bottom edge to get the angle. I marked that angle on the inside face, then used a square referenced on the bottom of the inside face to mark across the bottom edge. Then I could use the bevel gauge to mark the outside face. On the top edge I used a straight edge to join the two lines and mark across that edge.
83AB2697-912E-4038-8D76-12B3627D9D65.jpg
FBF95713-3D80-484B-8A02-905570869519.jpg

Then I cut each end, planed them, and butted each end against the other piece to check. When the pieces are propped at the correct angle with the blocks and they are square to each other, the butt joint should be tight. I had to do a tiny bit of fine tuning to get it right.

I marked my baseline by holding the pin board against the tail board and flushing them with my fingers. After marking the distance I could use the bevel gauge that matched the end angle of the tail board to mark the baseline on the inside face. I used a square referenced on the inside face to mark across the bottom edge, then the bevel gauge to mark the outside face. Then a straight edge to connect the two lines across the top.

I used the method from the “Half inch shy” video to figure my angles for my tails. I drew a line down the tail board parallel to the bottom edge of it. I laid out a 1:6 angle for the bottom of the tail and less steep angle for the top of the tail. Then I could set a bevel gauge referenced off the end of the board to mark the tails. The “square cuts” for the tails are parallel to the bottom edge, so they use the bevel gauge set to the same angle I used to plane the bottom edge bevel.

B15BC409-197B-481B-BF51-4E0ECEF1190D.jpg

cutting out the tails seems a little weird at first, but it is just follow the lines. Then you lay out the baselines on the pin board using the same method and put the pin board in the vise to mark out the pins.
75FCB4D0-2AC3-40B8-BA3C-14E558BD799F.jpg
to mark the vertical cuts for the pins you use the same bevel gauge that you used to cut the end of the pin board. Then it is just sawing and chopping out waste.

After you put the joint together you can mark the tops and plane them down. If I was doing this for real I would probably get one board close to my final height and leave the other one long. Then I could mark the other one after the joint is together and either plane it down when I take it apart before glue up, or just plane the whole thing down after glue-up. You could do some trigonometry to figure out how wide to cut each board ahead of time, but I try not to do math when I’m woodworking.

C99E09E9-FFEE-42E0-A2CC-44790BD6629F.jpg1478FA5F-4486-421C-B19D-962A2FC858FA.jpg