This Instructable will show you how I made the tapered legs shown in the photo from a 2x4. I used these as accents on an aquarium stand, which has its own Instructable here, but you could use them on a cabinet, a kitchen island, an office desk, dresser or other piece of DIY furniture.
Step 1: The Goal & Solution
Anyone who has used a table saw knows (or should know) they can be dangerous. Obviously, cutting a very shallow angle like the one used for these legs absolutely cannot be done safely by just sticking the board into the blade.
If cutting the board on the edge like this, the blade height, even when fully raised, is not tall enough to cut all the way through the 2x4, especially if held in a jig.
Another goal was to have a nice, potentially stainable grain on the outside edges of the legs. Any ugly unfinished tears to the grain of the board needed to be on the inside where no one would see it. Yet another goal was to not put any holes, nail or screw marks into any "finished" side of the board.
So, the solution is to make a jig that holds the board in place, and run the board through the table saw twice. Once on one side, then once on the other side.
Step 2: The Basic Box for the Jig
My tapered legs are 23.5" tall. They are made using a premium or "select" grade 2x4 that is 24" long, then very slightly trimmed to length when finished. A premium board has fewer knots, is straighter, and does not have rounded edges. You could use a regular grade 2x4 and run it through a planer to achieve similar results.
The jig sides are made from MDF and measure 26x7 inches on the two large flat sides. All other sides (the back and the two sides) are made from premium or "select" grade 1x4 pine. The point is you want something that will fit the 2x4 snugly on the sides, but leaves a slight gap on each end to give you room to place the 2x4 at an angle inside the box.
Step 3: The Shallow Spacer
Inside one end of the box, I placed and screwed in a larger block to be used as a spacer. It comes up to 3/16" inch from the top. I also slightly rounded the inside edge so that the 2x4 would not rest on that edge.
Thinking ahead, I drilled a hole in the back of the box and one on the side to help "pop out" a board from the jig if it got stuck.
Step 4: The Deep Spacer
The lower block in the photo comes up up so that it is 1 3/8" from the top and is also screwed in place I decided on this level by doing some calculations and verifying it with a 2x4 that was 24" long.
Step 5: Cut 2x4's to Length
You will want start thinking like a manufacturer now. Cut all of the 2x4s you are going to need to length first. Since my project required 8 legs, and each of these legs require TWO 24" 2x4's each, I cut 8 pieces. Actually, I cut a couple of extra ones too in case I made a mistake along the way.
Now since 2'x4's come in 8 foot lengths, to get four boards out of each board you will have to cut them a little shorter than exactly 24" long. The point isn't to get exactly "the right" length, but to make all of them exactly "the same" length. Cut them as close as you can and trim them if needed.
Step 6: Place the Board Into the Jig
Drop a board into the jig. You have another piece to fit still.
Step 7: A Snug Fit on the Shallow End.
The board needs to fit snugly on the shallow end, as pictured. Eventually those two picture hanging sized nails, going through pre-drilled holes, will hold that end of the board in place.
Step 8: The Deep Side Will Have a Gap
The side on the deep end will have a gap. So on this side, I placed a rectangular block which, when in place, holds the 2x4 and keeps it snugly held against the opposite/shallow end. You can see this small block of wood better in the second photo. This smaller block is removable when the two large screwes are removed - the purpose of that is to make the 2x4 easier to remove from the jig when needed.
Since all of your 2x4s are exactly the same length, they will now all fit the same way in the jig.
Step 9: Screw in the Board on the Deep End
I used screws on the deep end because there is more wood to "bite" into here. They go into pre-drilled holes that intersect about the mid-point of the 2x4". They pass over (or "through" would be okay too) and hold down the block mentioned in the previous step. Don't put the screws too close to the top or they will get in the way of the router bit later on..
Step 10: Nail the Board in the Shallow End
I used nails to hold the top edge of the tapered leg in place. There is only 3/16" of wood there to "bite" into, and screws could have potentially damaged the wood there.
After you have the nails in place, test the board to make sure you are comfortable that it is firmly held in place.
Step 11: Observe
The board in the jig now will look like this. Notice that in the photo about 1/4 away from the right hand side, the board starts to dip below the surface level. This intersecting line matches the desired height of the notch you will route out later on. (So of course, you could make adjustments to the height of the deep spacer on your jig to achieve that desired point).
Step 12: Raise and Line Up the Table Saw Blade
Make sure your table saw blade is set straight vertically.
Place the jig on the table and align the fence so that the blade will cut exactly along the outside of the jig.
For me, I had to raise the blade of the table saw as high as it would go, and then I could back off just slightly. At this height, it barely cuts half as high as the jig.
Step 13: Pass Number 1
Run the jig through the table saw. I'm not sure why, but it just made me more comfortable to run this edge in first on the first pass.
Step 14: Pass Number 2
Now flip the whole thing over and make a second pass. You can see from the photo that I did not have the depth quite high enough, so I had to actually run it through again this time.
Step 15: Observe, Then Repeat
Now you have a wedge which is ready to remove from the jig. To remove, unscrew the two screws. It will pop out from the nails from the other end if you pull the leg laterally and away from them.
Next, while your fence is in exactly the right place and everything is adjusted properly, you should repeat all of the steps mentioned to cut the desired number of wedges (2 per leg), plus maybe a couple of extras just in case you make a mistake.
Step 16: "X" Marks the Inside
Just to help orient you, I marked an "X" on what I will consider the "inside" of the board. This side with the "X" will be the part that glues to your cabinet. You can see in the second photo that the UPC sticker for the board is on the outside of the board. Use either the "X" and/or the UPC label on the board as you look at the remaining photos if you are confused about which side of the board you are looking at. This is important because the they are not interchangeable.
Step 17: So Now You Need to Cut a 45 Degree Angle on This Board
Here is the board next to the cabinet. Next, we want to achieve a corner by placing two of these together side by side. To do that, I need to show you how I cut the 45 degree angles. For this step, you will not need the jig, just your table saw and the fence.
Step 18: Set Your Table Saw to a 45 Degree Angle
You need to set your table saw at 45 degrees. If you have one like mine, don't pay attention to the gauge on the bottom, it only gets me in the ballpark. After measuring, you probably would even want to run a few 2x4 test scraps (not your prized-possession wedges) through to verify you are cutting as close to a true 45 as you can. But you knew that already, didn't you?
Step 19: Rip the Boards at the 45 Degree Angle
First, you need to place the board with the outside up. Referring back to what I was mentioning earlier with the photos, this means that you want the "X" side down and the UPC side up.
To achieve a good placement for the fence, I cut and made a couple of adjustments until the top edge of the blade intersected the top outside corner of the 2x4. Once the fence is set, leave it in the exact same place while you run HALF of your supply of 24" long boards through.
You have now made the "left" pieces of each leg. To make the "right" pieces, you will need to run the the remaining 24" boards through the table saw, but in such a way as to safely cut 45's on the other side of the board.
Step 20: Observe Again
In case it is not clear, this is what you have made so far. If you have no obstacles to get around, you may be done now and could be ready to trim to length. But, if you are building the aquarium stand, then you will need to cut out an area at the bottom that is 3/8" deep and as tall as the base frame to accommodate the base frame. To do this, we use the jig one more time.
Step 21: Return Each Board to the Jig
Put each board back in the jig. Put the nails and screws back in. There are already holes there in each board by now.
Step 22: Notice the Line
My base frame is 5 1/2 inches tall. So I need a slot that is at least that high. Again, it is more important to be consistent than exact, as you can always trim off any excess off the bottom. (Left untrimmed, the bottom of the wedge is not going to be a the correct angle anyway, so it will need trimming).
To create a consistent and straight line, I put the entire jig on my table saw sled and made a 3/8" deep cut. I left the board in place for the next step.
Step 23: Use a Router
I used a router with a square edge bit set to cut at 3/8" deep. I then used this to route out the notch, trying my best to avoid too much damage to the edges of my jig. The edges of the jig help hold up the router so that it remains level and cuts at a consistent depth. There are certainly other ways to achieve the straight line shown in the photo with the router itself (and a fence), but for me, I found the initial line cut with the table saw was effective.
Now that you have done this to one board, go test it on your cabinet or other project, then if you like it, repeat this step with the remaining boards. Then you are ready to sand and cut to length.
Step 24: Two Wedges Make One Leg
Make a stack of boards, place two of them together, and snap a photo like I did. You'll be proud that you finished making tapered legs out of a 2x4 and have a really cool jig you can use to make more of them.