How would you make an angled groove?

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Forum topic by Daiku posted 07-23-2015 03:15 PM 1007 views 0 times favorited 17 replies Add to Favorites Watch
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227 posts in 2325 days

07-23-2015 03:15 PM

Topic tags/keywords: joinery cabinet groove

I’m in the process of making a trapezoidal cabinet. I want to make grooves in the stiles (legs) to accept the 3/4” side panels. I’ve come up with a couple of ways that would work but would also be very cumbersome and was wondering if any of you out there have a simple way of solving. The grooves don’t run the length of the leg, so it limits what can be done on a table saw. There are 3 sketchup pictures attached, the bottom view shows where the sides and legs intersect and where the groove should be. Note, all 4 grooves will have a unique angle.

Thanks in advance for any ideas,


-- Cal Noguchi -

17 replies so far

View BinghamtonEd's profile


2263 posts in 1787 days

#1 posted 07-23-2015 03:29 PM

I’d make a sled/jig that had an sloped base, then run it on the router table with a straight bit. The resulting cut would yield the angled grooves you show in picture 3.

-- - The mightiest oak in the forest is just a little nut that held its ground.

View sras's profile


4363 posts in 2547 days

#2 posted 07-23-2015 03:31 PM

Here is the first thing that comes to mind:

1. Start with extra material on the side of the leg where the angled groove will be (You’ll have to figure out how much)
2. Cut that side to an angle that matches the direction of the panel.
3. Cut the groove (router table comes to mind)
4. Trim the side to be square.

-- Steve - Impatience is Expensive

View Ocelot's profile


1458 posts in 2056 days

#3 posted 07-23-2015 03:32 PM

Or you could make the legs trapezoidal at first, cut the groove, the re-cut them to the final square shape.

View sras's profile


4363 posts in 2547 days

#4 posted 07-23-2015 03:32 PM

Another idea would be to cut an angled tenon on the panel…

-- Steve - Impatience is Expensive

View Ocelot's profile


1458 posts in 2056 days

#5 posted 07-23-2015 03:33 PM

sras beat me to it!

View JayT's profile


4670 posts in 1629 days

#6 posted 07-23-2015 03:34 PM

Best power tool method would be a tilting router lift, but if you don’t have that, there’s no reason it can’t be done on a router table or table saw and finished with chisels. The methods suggested by Ed and sras would be my first choice if the wood chosen can accommodate it.

Edit: It could be done on a table saw with the blade tilted, but after posting, it’s not something I’m comfortable recommending on an internet forum. The other solutions are better and safer.

I don’t understand why all 4 angles would be unique? If its a true trapezoid, the angle should be the same, just two corners will be cut from the end to a stop and two would have to be started at a stop and finished out the end.

-- "Good judgement is the result of experience. A lot of experience is the result of poor judgement."

View bonesbr549's profile


1137 posts in 2485 days

#7 posted 07-23-2015 03:37 PM

I’d use a router table with the bit 90 to the table. then make a jig that is a wedge that the piece fits on and the bit extends up through the jig, and will cut it on any angle. I’d put a put a hinge on the bottom so you could set it to any angle to the base you want. Piece of cake.

-- Sooner or later Liberals run out of other people's money.

View Ghidrah's profile


667 posts in 640 days

#8 posted 07-23-2015 03:41 PM

I like the jig suggestion, If no one suggested it yet, and you’re looking for tight fitting shelf, I’d 1st do a mock up of the footprint then slide a straight edge against the backside of the front posts to meas. the offsets then do the front of the rear posts to ensure there are no discrepancies between them then build the jig according to the offset.

-- I meant to do that!

View dawsonbob's profile


1830 posts in 1173 days

#9 posted 07-23-2015 03:56 PM

Many trim routers, such as the Bosch Colt, have tilting bases available just for this type of work. If you have a trim router available, you might want to investigate those bases.

-- Mistakes are what pave the road to perfection

View rwe2156's profile


2110 posts in 899 days

#10 posted 07-23-2015 04:32 PM

What’s wrong with a tilted dado blade with a stop cut and multiple passes?

I don’t know how you can do an angled tenon on a panel. Guess I”m missing something.

-- Everything is a prototype thats why its one of a kind!!

View Ghidrah's profile


667 posts in 640 days

#11 posted 07-23-2015 05:47 PM

I’d consider it a dado and an angled jig. (wedge) equal to the offset

-- I meant to do that!

View Daiku's profile


227 posts in 2325 days

#12 posted 07-23-2015 05:51 PM

First I want to thank you all for your suggestions, you’re better than Google!

Steve (sras) – Your suggestion is one that I had in mind, but I didn’t like the idea of having either an angle against the fence or a corner.

I’m sure there’s a workaround for that, but I’ve decided to take the suggestion of many and make a ramp jig for the router.

JayT – I mentioned 4 unique cuts because the groove wasn’t going to be centered, they would have a 1/2” reveal. I will probably center them in which case, you’re right, there will be 2 unique cuts

I thought about using a table saw w/ dado set, but I (like JayT) didn’t like it since you’re raising the blade blindly in the middle of a cut.

Thanks again,

-- Cal Noguchi -

View AlaskaGuy's profile


2392 posts in 1727 days

#13 posted 07-23-2015 05:52 PM

Looks like a simple cut on a table saw with a dado blade set at an angle.

-- Alaskan's for Global warming!

View Boxguy's profile


2121 posts in 1685 days

#14 posted 07-23-2015 06:28 PM

Cal, I like simple. Cut this on a table saw with an angled dado blade. Better if you have a Wixey or some such electronic angle gauge. Have some stock for sample cuts to check your blade position, height, and angle. Cut the groove the full length of the leg and just fill in the upper part that you don’t need. Use a contrasting wood and celebrate the cut, don’t try to match it in. Make the filler square, glue it in, and plane off the excess after the glue dries. With say 3 inch sample blocks, and 3 inch strips of plywood or whatever your back board is, you can make a quick mock up and try it in the space for size and make minor adjustments if you need to. Then use the sample blocks and/or Wixey to quickly reset your angle and fence.

I have made some triangular display boards and encountered some of the same problems you are facing. I found that with this dado and fill-in method you get tight joints at the top of your back boards; you can accommodate cutting from both ends of the legs, which should help set-up; you don’t have stops to worry about; and I think you might even like the look of the stripe. Dadoes are adjustable for your back board thickness and the whole process becomes much, much simpler. You can even set your boards up from the floor easily by just filling in the dado at the bottom and fitting your back board into the slot.

-- Big Al in IN

View Ghidrah's profile


667 posts in 640 days

#15 posted 07-23-2015 06:39 PM

Daiku, sorry, I misunderstood because I didn’t read your entire post, I was distracted by the highlighted shelf, I assumed you wanted a method for cutting the shelf slots.

Because you’re cutting into the length of the posts for side panels I now believe you should use the dado blade and the jig to make the cut in 1 move instead of multiple passes with a single blade.

If you intend on multiple shelf projects with the same profiles I’d suggest fabricating an enclosed jig to safely house and secure the posts then use a router, preferably a plunge router to cut the dadoes.

-- I meant to do that!

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