Introduction: Sliding Dovetail Stop Block
Here in the Make Things Laboratory (pronounced LAY-BOAR-A-TORY (think Dexter's Lab)), we've been on a bit of a crosscut sled binge. We hooked up the electrodes to the leftover pieces of old jigs discarded and nearly buried in the backyard and waited for the perfect lightning storm. While Clyde and Egor trampled through the mud to hook in the extension cords, I greedily opened the sky window and cranked my pile of rubbish to the sky.
What followed was a flash of lighting, a couple grunts from my toadies in the backyard...and a rumbling of moving wood. "It's alive, alive I say!"
The first of the new additions was the box joint crank, found in our last instructable. In this instructable, we're going to uncover the sliding dovetail stop block, which will allow a woodworker the ability to place the stop block on a precise measurement, lock it into place with a knob on top, and cut (with precision) their stock.
But first, there are other expensive methods to do the same thing on the market. This jig will save that extra hundred bucks for exotic woods and other materials needed for the important stuff.
Follow me now as we enter the laboratory. Just watch for singed Clyde and his brother Egor, they haven't been acting the same since...
Step 1: Step 1: Gather Materials / Tools Needed and Used
Material List
- 2x6 Length of your crosscut sled
- A scrap 2x4 also the length of your crosscut sled
- 1/4" x 1 1/2" Carriage bolt
- 1/4" Wing nut
- 1/4" T-nut
- Glue
- Epoxy
- Double sided tape
Adhesive measuring tape https://amzn.to/2XQ24zX
Tools Needed and Used
- Table saw
- Measuring tape
- Clamps
- Carpenter's Square
- Hammer
Step 2: A Few Basics and Prepping
If you've followed my youtube channel, you'll know that I have a method to bringing about my final design. I do this to keep Egor and the other slap head (Clyde) busy with the prototype as I search for ways to make the project a little more advanced. The sliding dovetail I'm going to show you was my prototype, but don't be fooled: It was an excellent prototype the development team here churned out. I would very easily use it and not the final one I came up with, if it weren't for the garbage sled I attached it to that I keep threatening to throw away.
This is such a cool addition that it's changed my habits away from using my miter saw for smaller cuts as well as dado's (my son and I made a DVD shelf just yesterday with it). So you'll see, in this instructable, some ideas I had for advanced versions...that really aren't necessary. On its own, you will be happy with this with more money in your pocket!
The first thing we want to do is to remove those rounded corners from our 2x6. This is common problem with these pesky species of pine that grow the rounded corners. Factories love them because all they have to do is chop them down and cut them to length. We woodworkers hate them...because, well they look like they're construction lumber.
Simply run them through your table saw, cutting off about an 1/8" on each side so that we have a nice, square 2x6.
OKAY, that being finished, we'll cut the 2x6 to be the length of your sled.
Step 3: Supersize Your Sled!
In order for us to build a nice stop block track with an adhesive backed tape right down the center, we'll need to make this track a minimum of 1 1/2 inches. The plus side? That's the width of a 2x6. The downer? We'll have to build your fence outward, from the front to the back, that is, if your fence isn't already 1 1/2" wide. I know, I hear the moans from your throats, but it's that lousy measuring tape!
Seriously, it's not a hard fix. All we'll need to do is measure the width of our sled and subtract that amount from 1 1/2". If you look at the picture I've left here, you'll see that my fence width was about 5/8". I subtracted 5/8" from 1 1/2" and had 7/8" left. I cut a block of wood that was 7/8" and glued it to the back of my sled. That fixed it. Let's move on to the next step.
Step 4: Saw Set Up and Channel
We're now going to set your saw up to cut sliding dovetails. Simple really. Adjust your saw blade so that it's at a 45° angle. Next find the very center of your table where the teeth of your saw reach the pinnacle of spinning glory above your table saw. Draw a line when you find that center. We'll use this line to measure off of, so it's important that it's dead center. Next we'll place a measuring device of some kind on the line and retract the blade into the saw until the highest tooth of the blade is at 1/4".
This is where the fun comes in. Now you'll take the thickness of your 2x6 and run it against the fence and through the blade. You'll flip it and do the parallel side. You'll move your fence in towards the blade about a 1/16 of an inch and you'll make a cut, and flip the wood like the last time and make another cut. You'll do this a couple times until you have a peak. I've included a picture to show the final look.
Give that cute little pyramid a few glances, bask in the small rewards that simple geometry provides and know that it'll be wiped out of existence just a couple steps away.
Step 5: Sliding Tails...
Now that we've made a geometrical valley, we're going to make a sliding piece that fits in that valley. And it's extremely simple. We'll take our fence from the right side of the blade and put it on the left side. We'll measure over 1 1/16", again with the top of our blade to the fence. Yes, this is exactly like the last step, except mirrored. No, we won't raise or lower our blade. Leave it be.
Now we'll turn the valley upside down and face our uncut board down against the tabletop. Once there, we'll do the exact same thing as the first part of our last step. Ugh, such a conundrum of words. We'll push our board through the blade, flip it horizontally and do the other side. Folks, really, if in doubt, check the video link out. I know it sounds like I'm trying to get you to watch my video...but I don't want you to fail.
Now, we'll move the fence once again. Instead of moving the fence towards the blade, we'll be moving the fence away from the blade, a 1/16" at a time. I've included a picture to show you how it should look at the end.
Step 6: Tear Down the Pyramid
Funny, I had Pink Floyd rumbling in the background of my head while making the title of this step.
Tear down the wall! Tear down the wall!
In this step, we'll be removing that center pyramid goblin as well as separating our sliding tail and valley. It'll be easy, too. All you'll need to do is move your blade from a 45° back to 90° (or is it 0°?). Again, don't raise or lower the blade. You'll move the blade in as close to the pyramid base as you need to, lock your fence and make passes again until your blade hits the center.
Simple!
Once that's complete, move your fence a 1/2" away and cut the valley off. For the sliding tail on the opposite side, we'll move our fence to 1 and 1/4 inches and cut off the tail.
Now try and slide the tail into the valley...it should fit like a glove.
Step 7: Forming the 'Sliding Tail'
For review, the sliding tail is what will slide in the track. Because we're keeping this simple and not including a drill press (and less face it, drill presses aren't always as accurate as we want them to be, especially with vertical pieces), we're going to form our sliding tail on the table saw. Okay, I see on your faces that there's some doubt. Trust me, it's easy.
The first thing that we'll want to do is cut two pieces off of the long sliding tail that we cut in Step 5. Cut them at 7/8" each...or heck, go nuts and make it 1". Simple.
Now that we have both pieces, I would recommend using some double sided tape...very much recommending that tape to be carpet tape as it has a strong hold. We'll take and tape the tops together, as seen in the pictures included, making them as lined up as we can. Still, very simple.
Set your blade so that it's at 3/16th of an inch above your sled base.
Next we'll put the connected pieces on our sled in the path of the blade, lining one of the tails on the fence. Check out the included video and pictures. Now, OF COURSE, we aren't going to use our fingers to hold that tail down as that would be idiotic and extremely dangerous. Instead, we're going to use a surrogate board that we'll place over the top of the connected tails. It'll be pressed up against the fence and you'll hold it with force pressing downwards with your fingers far, far away from the blade. No thinking you're the one person that can cut this piece with your bare hands. Those few people that think they can do it, eventually end up with missing digits.
Once' you've notched out a 5/16" wide width, as centered as you can make it, we'll now glue those two pieces together as shown. BEFORE you add the glue, be sure that your 1/4" t-nut slides easily in the groove.
Step 8: Making the Arm
Well what is 'The Arm'? The arm is where you'll put your stock when it'sa cuttin' time. This 'arm' will also be what's connected to your sliding tail, so it needs to be accurate. With the leftover pine from the 2x6, we'll cut it to be the exact width of your sliding tail. I can tell you how wide it should be, but I'll let you find the size yourself (since, in the last step, you were given width options). So...that's right, go ahead and measure how wide your sliding tail is and set your fence on your table saw that width away.
Once that's done, we'll hold it up against the sliding tail and draw a line. Then we'll cut the excess off with our crosscut sled. Afterwards, we'll add a thin piece of wood under the arm before lining up the sliding tail to it (see pictures). This thin piece of wood will give it just enough of a boost that it won't rub against the base of the sled.
Now, assuming that the the sliding tail in the last step is dry, we'll put a little epoxy on the under side of our t-nut and smack it in. I did it while it's in the track...but it really doesn't matter. Just don't put so much epoxy on that it drips down the square hole you made!
Since you probably still have a bit of epoxy left over, we'll go ahead and glue the butterfly nut onto the carriage bolt. Thread the butterfly on so that the wings are pointed towards the head of the bolt and add a little bit of epoxy right below the head, twisting the epoxy on afterwards. Then I use a hot glue gun and added a small drop on the end of the bolt. This will keep the metal tip from destroying the tape. Set it aside and allow it to cure.
Next we'll use a carpenter's square and line up our arm...both sides of the arm should be square. Once it's set and you've added a clamp, double check everything. Make sure that the arm is square to the end of the sliding tail. The sliding tail will be where we measure from, so the arm needs to be perfect with it.
Step 9: Adding Our Tape
I'll have to admit that the video does not do this step justice. It was pointed out by Keith O. (I haven't asked permission to use his full name, but his name is in the comments of the video) that my idea of chasing the tape in the middle would keep it from being accurate. I fully agree and he had an excellent suggest that I'll post here:
"Keith O": Nice build! (FWIW, chasing the bulge in the tape back to your zero point will screw up where it sits. A better way is to remove a portion of tape from the *middle*, hold that portion up off of the surface while you find your zero point, then press it down. After that, you can remove the rest of the tape without the zero point shifting.
With this great tip, we'll start. The first thing you'll want to do is slide the arm over to your blade. You'll want it to touch the blade but not cause the blade to deflect (move horizontally) in any way. Next, with the backing still on the tape, slide it under the sliding tail so that '0' on the tape is just barely under the edge of the sliding tail. Tighten down on the bolt enough that the tape is secure.
On the other side of the sliding tail we'll find the center, flip it over and remove about an inch of the backing. Next, we'll stretch the tape out as much as we can and press the tape where we remove the backing inside the channel. Check, double and triple times that the tape is flat to the channel. Also check again that the tape hasn't move on the opposite side of the tail. When you're sure everything is solid, loosen up the bolt and take off the arm and sliding tail (glued of course) from the sled. Now lift up either side of the tape and remove the backing, pressing down.
Step 10: Advanced!
With my advanced step, I'm not going to go into a lot of detail on how I made my advanced version. This 'step', really, isn't a step at all. It's a suggestion, or reflection page. Often, when I make things (ohh, hence the name?), I get ideas on how to make improvements. I often like to make prototypes that work, and then switch to hardwoods...because beautifully made jigs really encourage me to make beautiful things in my workshop (instead of just piecing together things for utilitarian reasons).
My biggest suggestion to any jig that you make is to be creative, make it your own. I used pine in all of my steps, but you don't have to. I used yellow heart, purple heart, ebony and pauduk for the final arm and hard maple for the sliding tail. I also decided to go with a triangle wedge instead of just gluing the arm to the side of the sliding tail...just because it looked neat to me. The track was made out of jatoba due to it's strength and hardness. These are all very impractical ways to make something that just sits on your table saw sled, but I really think people often times buy things in the store instead of making those items because they love the look and feel of something that's nice. We can make nice things, even our jigs!
The other minor idea I decided to add was the ability to move the track and lock it in place. This is also a very impractical idea if you plan on always using a thin kerf blade...which is 99% of all blades you can buy in the store. Really the only time you'll ever move up from 3/32" to an 1/8" blade is when you spend a good $100 bucks in the store, and really, the only time you'd buy a blade like that is when you plan on sharpening it. My final thought on the sliding feature: it was an over engineered idea that sounded good but now feels a bit of a waste.
I'm certainly not going to push anyone to watch how I made the final version, but if it gives any inspiration to you at all in personalizing your jig, I'm gungho. I personally think you'll find no greater satisfaction in your workshop than using your own tools that you have personalized. That satisfaction will easily transfer itself into the works of art that you create from those tools.
Step 11: Troubleshooting + Thank You!
PLEASE, PLEASE,PLEASE! ask questions if you have any difficulties. I'm leaving this page here to help those that have problems with this build. Be the first to ask a question and I'll be as quick as I can be to answer that question for you...I promise!
If you like my work, please follow me here and on Instagram, as well as a sub on Youtube. Thank you!