compound angle dovetails?

[Michael J Evans]

Anyone got any special tips or tricks for compound angle dovetails?

The wife wants what essentially is a serving tray (Google: butler tray), with splayed ends and sides. I wanted to get it done, so I spent two days trying compound miters with the tablesaw as that seemed very fool proof. My old craftsman tablesaw is less than ideal and not very accurate but I keep it around for rough ripping. Anyways... I got crap results. I generally feel much more confident with hand tools, as I've spent more time with them, so I decided I would try my hand at compound dovetails. I watched Bob Rozieski's video about 30 times, a video by "half inch shy" about 60 times, Bobs video another 10 times while laying out, and finally made some cuts tonight. I am a inexperienced dovetailer as it is and knew these were likely 100 times above my level, but as my Dad always said "If you don't shoot, you won't kill" (hunting reference), so I finally made the attempt tonight and totally butchered the first set. I am going to go with square sides for now, so I can actually produce something, but this isn't the last this joint has seen on me.

Some things I've learned along the way is, 1) double sided tape and some extra off cuts are very handy with holding up the pieces. 2) Not all sliding T bevels are created equal... For such a simple tool, I've come to learn my Empire won't lock down tight and moves if you look at it wrong. Whereas my old rusty $5 Stanley (rear locking) won't budge at all. 3) You need 20 T-Bevels... I think you technically only need one, but I had two and wish I had four. 4) You have to reset the T-bevel for each side of the slope of the Dovetail. I may be really slow, but I didn't catch this during my 100 video views and spent about two hours in the shop, watching Bob's video trying to figure out why my tails were not sloping correctly.

So what have been your experiences and path to success for this joint?

Thanks
Michael

[Jim Koepke]

Sometimes this makes me wonder if a surround could be made normally and then splay the outside with a hand saw, table saw or bandsaw. Then work the inside with a coping saw or gouge. You might need to keep the square corners on the inside.

Just a thought.

Cutting the way you are will likely work better. What you will likely need to do is practice it a few times using scrap wood.


Not all sliding T bevels are created equal... For such a simple tool, I've come to learn my Empire won't lock down tight and moves if you look at it wrong. Whereas my old rusty $5 Stanley (rear locking) won't budge at all. 3) You need 20 T-Bevels... I think you technically only need one, but I had two and wish I had four.

When my T bevel gauges come out, there are almost always two set to supplementary angles (such as 45º + 135º = 180º). There is also a piece of scrap with the angle drawn on it for quick checks.

There are maybe eight in the shop and more would be handy. Maybe it should be at least two of each size.

jtk

[Doug Dawson]

Anyone got any special tips or tricks for compound angle dovetails?

The wife wants what essentially is a serving tray (Google: butler tray), with splayed ends and sides. I wanted to get it done, so I spent two days trying compound miters with the tablesaw as that seemed very fool proof. My old craftsman tablesaw is less than ideal and not very accurate but I keep it around for rough ripping. Anyways... I got crap results. I generally feel much more confident with hand tools, as I've spent more time with them, so I decided I would try my hand at compound dovetails. I watched Bob Rozieski's video about 30 times, a video by "half inch shy" about 60 times, Bobs video another 10 times while laying out, and finally made some cuts tonight. I am a inexperienced dovetailer as it is and knew these were likely 100 times above my level, but as my Dad always said "If you don't shoot, you won't kill" (hunting reference), so I finally made the attempt tonight and totally butchered the first set. I am going to go with square sides for now, so I can actually produce something, but this isn't the last this joint has seen on me.

Some things I've learned along the way is, 1) double sided tape and some extra off cuts are very handy with holding up the pieces. 2) Not all sliding T bevels are created equal... For such a simple tool, I've come to learn my Empire won't lock down tight and moves if you look at it wrong. Whereas my old rusty $5 Stanley (rear locking) won't budge at all. 3) You need 20 T-Bevels... I think you technically only need one, but I had two and wish I had four. 4) You have to reset the T-bevel for each side of the slope of the Dovetail. I may be really slow, but I didn't catch this during my 100 video views and spent about two hours in the shop, watching Bob's video trying to figure out why my tails were not sloping correctly.

Uncle Cletus taught me to build it like it was square, and then shave stuff off to look like it wasn’t. At the very worst it would look like something the set decorator for a sci fi movie had ordered up. How can you lose.

[Todd Trebuna]

Anyone got any special tips or tricks for compound angle dovetails?

The wife wants what essentially is a serving tray (Google: butler tray), with splayed ends and sides. I wanted to get it done, so I spent two days trying compound miters with the tablesaw as that seemed very fool proof. My old craftsman tablesaw is less than ideal and not very accurate but I keep it around for rough ripping. Anyways... I got crap results. I generally feel much more confident with hand tools, as I've spent more time with them, so I decided I would try my hand at compound dovetails. I watched Bob Rozieski's video about 30 times, a video by "half inch shy" about 60 times, Bobs video another 10 times while laying out, and finally made some cuts tonight. I am a inexperienced dovetailer as it is and knew these were likely 100 times above my level, but as my Dad always said "If you don't shoot, you won't kill" (hunting reference), so I finally made the attempt tonight and totally butchered the first set. I am going to go with square sides for now, so I can actually produce something, but this isn't the last this joint has seen on me.

Some things I've learned along the way is, 1) double sided tape and some extra off cuts are very handy with holding up the pieces. 2) Not all sliding T bevels are created equal... For such a simple tool, I've come to learn my Empire won't lock down tight and moves if you look at it wrong. Whereas my old rusty $5 Stanley (rear locking) won't budge at all. 3) You need 20 T-Bevels... I think you technically only need one, but I had two and wish I had four. 4) You have to reset the T-bevel for each side of the slope of the Dovetail. I may be really slow, but I didn't catch this during my 100 video views and spent about two hours in the shop, watching Bob's video trying to figure out why my tails were not sloping correctly.

So what have been your experiences and path to success for this joint?

Thanks
Michael


I haven't done this...but Bob Rozaieski (https://www.youtube.com/channel/UCbHEdqSJEG0RIiJfeF5-LCA) has. Take a look on youtube. He's got a great video on it. It's about 40 minutes of good watching. Search for Compound angle dovetails.

[Jason Buresh]

I have no clue if this would work, but would it be possible to leave the pieces fat, cut all of the joinery and test fit while square, and then run the pieces through the table saw with the blade set to the desired angle?

I have no experience with this, just thinking out loud.

[Richard Line]

Popular Woodworking had an article on making them. Go to their web site and search on 'compound dovetails' for the article. I also found a compound angle calculator, use this link http://www.pdxtex.com/canoe/compound.htm.

I'm still playing with them, have a tray, something like in the PW article in process. I'll warn you, dyslexia isn't a help.

[Ben Ellenberger]

Shoot, I wrote up a big reply, then lost it. Here’s the best video I found, which helped me figure out compound angle dovetails. Definitely cut a few test joints first, and pay close attention to whether you are measuring an angle in the plane of the table top (the sides come together square in that plane) or if you are measuring perpendicular to the faces of your pieces (the ends are not square to the faces).

https://www.youtube.com/watch?v=e9h9maJNFAc

I did everything by hand, so I didn’t calculate angles for a table saw, but you can do it with bevel gauges and projecting angles from one piece onto another. I settled on how much each side would tilt out first, and cut blocks with those angles and beveled the bottom of each piece. That gave me blocks to prop each side on at the correct splay angle as I projected the angles that the ends needed to be cut at.

here’s the tote I ended up with. I was happy with how it turned out.

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[Ben Ellenberger]

I just looked at that popular woodworking article. If you try to mark your baselines using a marking gauge referenced on the end of each piece, you will end up with gaps. The outer baseline would need to register on the edge of the outer face, with the stem parallel to the face of the piece. The inner baseline would need to register on the edge of the inner face. Since the edge is not square to the faces, this doesn’t work. The fence is going to always register on whichever edge sticks out further.

Your baselines are parallel to the end of each piece (so if your sides splay out at two different angles, each baseline will be at a different angle). After cutting the ends of each piece to the correct angle and locking in a different bevel gauge to each angle, here’s how I marked my baselines:

first, lay the piece you want to mark flat on the bench. I cut tails first, so that’s what I marked first. Stand the second piece on top of it with the correct end butting in and flush them with your fingers. Make a small mark on the inside to determine how far back the inside baseline needs to be. (If this sounds exactly like how you would normally mark a baseline with a square, that is because it is. The only thing different so far is that the two pieces are butting together at an odd angle). Use the bevel gauge for the tail board and register off the bottom to mark your inside baseline. Now, take a square and take the baseline across the bottom of the piece to the outside face. The bottom is already beveled at the splay angle. If the edge is cut square and you try to take your baseline from the inside to the outside, you’ll end up with a gap. Once you’ve taken the baseline from the inside to the outside, you can use your bevel gauge referenced off the bottom to mark the baseline on the outside.

I didn’t bevel the tops of my pieces until after I cut the joints, so I just had to connect the two baselines across the top with a straight edge. If I had cut the bevel on the top too, I could have used a square to join the two baselines. This is because the square would then be laying in the same plane as the bottom of the box.

[steven c newman]

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Tool tote...now is a planter on the front porch..
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All hand cut..
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Includes the stopped dado for the handle

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End piece...
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Doing some clean up, after the glue-up...

[Michael J Evans]

Sometimes this makes me wonder if a surround could be made normally and then splay the outside with a hand saw, table saw or bandsaw. Then work the inside with a coping saw or gouge. You might need to keep the square corners on the inside.

Just a thought.

Cutting the way you are will likely work better. What you will likely need to do is practice it a few times using scrap wood.



When my T bevel gauges come out, there are almost always two set to supplementary angles (such as 45º + 135º = 180º). There is also a piece of scrap with the angle drawn on it for quick checks.

There are maybe eight in the shop and more would be handy. Maybe it should be at least two of each size.

jtk

Jim
I think beveling the outsides would be easy enough, but then like you said the inside would still be problematic. If it was a box with a lid, maybe not so much and the interior wouldn't be seen all the time.

I am going to keep a look out for more T-bevels. I just bought the Stanley rear locking type before this project and really like the rear lock mechanism and how tight it locks up. The only other new one I can find that has that rear lock is a Japanese one but its $30. I picked up the old stanley for $5, I'm hopeful I'll find another.

[Michael J Evans]

I haven't done this...but Bob Rozaieski (https://www.youtube.com/channel/UCbHEdqSJEG0RIiJfeF5-LCA) has. Take a look on youtube. He's got a great video on it. It's about 40 minutes of good watching. Search for Compound angle dovetails.

Hi Todd,
That was one of the videos I was referencing in my original post. I found his video well done, It just took me quite a few views to really understand what was going on, and then a few more views, while laying out. The dovetail slope is what really threw me off as I didn't realize you had to reset the bevel gauge for each side of the slope.

[Michael J Evans]

I just looked at that popular woodworking article. If you try to mark your baselines using a marking gauge referenced on the end of each piece, you will end up with gaps. The outer baseline would need to register on the edge of the outer face, with the stem parallel to the face of the piece. The inner baseline would need to register on the edge of the inner face. Since the edge is not square to the faces, this doesn’t work. The fence is going to always register on whichever edge sticks out further.

Your baselines are parallel to the end of each piece (so if your sides splay out at two different angles, each baseline will be at a different angle). After cutting the ends of each piece to the correct angle and locking in a different bevel gauge to each angle, here’s how I marked my baselines:

first, lay the piece you want to mark flat on the bench. I cut tails first, so that’s what I marked first. Stand the second piece on top of it with the correct end butting in and flush them with your fingers. Make a small mark on the inside to determine how far back the inside baseline needs to be. (If this sounds exactly like how you would normally mark a baseline with a square, that is because it is. The only thing different so far is that the two pieces are butting together at an odd angle). Use the bevel gauge for the tail board and register off the bottom to mark your inside baseline. Now, take a square and take the baseline across the bottom of the piece to the outside face. The bottom is already beveled at the splay angle. If the edge is cut square and you try to take your baseline from the inside to the outside, you’ll end up with a gap. Once you’ve taken the baseline from the inside to the outside, you can use your bevel gauge referenced off the bottom to mark the baseline on the outside.

I didn’t bevel the tops of my pieces until after I cut the joints, so I just had to connect the two baselines across the top with a straight edge. If I had cut the bevel on the top too, I could have used a square to join the two baselines. This is because the square would then be laying in the same plane as the bottom of the box.

Ben thank you for the detailed reply.
I ripped the bevels with table saw and then did everything else by hand, projecting angles and all that. In regards to using the marking gauge to mark the baselines, I followed what Bob Roziaski showed in his videos, which was to set it to the thickness of the material and then add the difference from the off square ends ( is this miters?). You then mark all of the outer base lines, use a square to transfer to the edges and then reset the marking gauge to get the lines to match up and do all the inner faces. In his and my scenario both edges are beveled. I guess the idea is since you added the extra to the setting of the bevel gauge, it then gives you a little bit to plane off later. In my case I overly compensated and when the joint went together I had a 1/8" or more that would've needed to be planed off.

[Ben Ellenberger]

Ah, ok. I haven’t seen that bob roziaski video. The other videos of his I’ve seen make me believe he is very thorough and thoughtful, so I’m sure his method is good. It sounds like he addresses the issue with referencing the marking gauge by re-setting it for the inside and outside faces. That sounds like it would work.

for me, using bevel gauges to mark baselines instead of marking gauges made the whole process easier to wrap my head around.

[Warren Mickley]

In the 1980s I made slope sided trays for the wholesale trade. I usually made a dozen at a time. There are three angles needed to prepare stock for dovetailing.

1) the splay angle, the angle from the face of the board to the bottom.

2) the angle from the bottom to the end edge, which is slightly less extreme than the splay angle

3) the angle from the face to the side edge, which is slightly less than 90 degrees.

I calculated these angles (three dimensional trigonometry) years ago, but now I use a different method. I now take a block of wood, like 2X4 or 3x3 and plane one side and one end of the block to mimic the slope I want. I then have one corner that I can use to set the bevel gauge for the three angles.

If the ends of your tray sides are planed at the correct angles, (might be 87 degrees or so), you can use a marking gauge to lay out the lines for the dovetails. Rosaieski doesn't even try to get this right and so ends up with a very clumsy method.

[Michael J Evans]

In the 1980s I made slope sided trays for the wholesale trade. I usually made a dozen at a time. There are three angles needed to prepare stock for dovetailing.

1) the splay angle, the angle from the face of the board to the bottom.

2) the angle from the bottom to the end edge, which is slightly less extreme than the splay angle

3) the angle from the face to the side edge, which is slightly less than 90 degrees.

I calculated these angles (three dimensional trigonometry) years ago, but now I use a different method. I now take a block of wood, like 2X4 or 3x3 and plane one side and one end of the block to mimic the slope I want. I then have one corner that I can use to set the bevel gauge for the three angles.

If the ends of your tray sides are planed at the correct angles, (might be 87 degrees or so), you can use a marking gauge to lay out the lines for the dovetails. Rosaieski doesn't even try to get this right and so ends up with a very clumsy method.

Warren
Do you mean if the ends (end grain) are planed at the correct angles then you can just use your standard marking guage?

I was wondering why we didn't just plane that bit to fit, but decided he knew better and likely it was because it would be difficult to accurately plane a small piece of end grain to a specific angle (at least for me)

[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?

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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?

446731

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
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Here is the bevel for marking out the ends of the tray sides 75.5 degrees:
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Here is the bevel set for the angle from the face to the ends 93.8 degrees;
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[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 (https://f001.backblazeb2.com/file/dc-share/angled_dovetails.pdf) 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 (https://f001.backblazeb2.com/file/dc-share/angled_dovetails.pdf) 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.

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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.
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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.

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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.
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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.

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