Setup for sliding dovetails

I'm about to have to make a few drawers and decided that I'd try to make doing the sliding dovetails EZ'er. I have drawn this, done a prototype, tested the concept, and have started building the parts needed. This is what I came up with. It was influenced by Dino's M/T setup, and an idea I got from the Woodrat video (a technique, not the tool).

The setup has three parts, a vertical SME with clamps to hold the work piece that will get the sliding dovetail (pin), a vertical SME to hold a horizontal platform for the work piece to receive the sliding dovetail slot, and a top platform for the SRK base to ride on (it has two large holes for the bit).



Both work pieces are mounted flush to the bottom of the top platform that supports the SRK base. The piece receiving the slot is easy, the horizontal platform is raised, with the work piece in place, until the work piece is against the bottom of the top platform. I need to come up with a method to assure the other piece is placed properly. This is essential to the functionality of the setup. I will probably come up with an insert to allow placing the piece, that will then be removed. To do multiple pieces of the same length, I'll have to incorporate a stop in the edge of the SME to hold the piece at the proper height.



Once the test pieces are in place, you lower the dovetail bit until it just touches the vertical piece. Then you center the bit on the piece and make a pass along the full length of the piece. This will make a mark in the top of the piece. This mark is what you will use to align the bit for the passes along the sides of the piece.





Next you lower the bit to the depth you want the slot to be. Then align the bit with the location you want the slot on the other piece and make the cut (either through or stopped).





You then move the router toward the inside of the horizontal piece and align the edge of the cutter at the top of the piece with the inside mark on the top of the piece.



Set the SRK limit stop closest to the piece. Make a pass to cut that side of the dovetail.



Move the router out and line up the inside edge of the cutter with the outside mark on the top of the piece and set the other limit stop.





It is best if you start with the cuts a little too far out from the piece so you can sneak up on the final setting. Test the fit and adjust as necessary.

Your passes are in the counter clockwise direction (not the usual direction) to get a cleaner cut.



I added the drawings of the technique to clarify my written description. If it is still not clear, please let me know, and I'll see what I can do to make it clearer.

Dik

Dik, I'm not sure I fully understand your description of how you set up the cuts but I'm sure your future diagrams, (And maybe some videos?) will be very helpful. I'm interested in this because I'm planning on making some drawers and assembling the sides to the front and back using sliding dovetails. I've done some practice drawers with scrap on my router table with decent results but I'd rather do it using the SRK. Keep up the good work.

Bruce

Bruce, I hope that the added pictures and edits help. Please feel free to ask any questions if I still haven't made things clear.

Dik

Great job Dik. Seems pretty self explanitory to me. The pictures really help for those who can't visualize.

Dale

Dik,

This setup is great. Your explanation and drawings are very clear.

Thought: You now have two slots in top of the jig. How about changing that to one long slot. Stops could be aligned so that you cut 1/2 of the Pen and then continue on to cut the slot in the drawer side. On the return trip, you cut the other half of the pen.

Burt

Burt wrote:

Dik,

This setup is great. Your explanation and drawings are very clear.

Thought: You now have two slots in top of the jig. How about changing that to one long slot. Stops could be aligned so that you cut 1/2 of the Pen and then continue on to cut the slot in the drawer side. On the return trip, you cut the other half of the pen.

Burt

Dik - Your SU does wonders for understanding your ideas. I was thinking the same thing as Bart (blue). Also, I think you could modify your jig to cut long sliding DT rails for the drawer slides???


Mike

Burt,

I haven't built that part yet, but had thought of doing that. I designed it with two holes to add to the support of the SRK, but that might be unnecessary. I think your process would work great. I'm thinking about how to do a stop/register for the horizontal piece. I need to design it so that the slot will line up with one of the other cuts. Not sure how to accomplish this. Any ideas?

Dik

Dik Harrison wrote:

Move the router out and line up the inside edge of the cutter with the outside mark on the top of the piece and set the other limit stop.

Dik, just an idea.
Instead of resetting the SRK to make the second pass, maybe is better to turn the wood.
This way you are sure that the dovetail is centered.

Andres.

Dale Sudhoff wrote:

Great job Dik. Seems pretty self explanitory to me. The pictures really help for those who can't visualize.

Dale

Uh, thanks, Dale. Nice jab. Keep in mind that the content of Dik's post more than doubled after I made my comments and before you made yours.

Bruce

Dik Harrison wrote:

Bruce, I hope that the added pictures and edits help. Please feel free to ask any questions if I still haven't made things clear.

Dik

Dik, it's more clear now. I guess I understood it before but I was thinking there was some way that would allow you to cut the vertical piece without having to creep up on it. Also, as Andres said, centering it is important too.

As I said, I've made sliding dovetails like this on my router table and they came out well. But the tricky part is that you have to creep up on that vertical piece to get it just right. I was thinking that I was missing something from your original description that eliminated the trial and error of the, "Creeping up" part.

That's one thing about the, "Exact dado" done with the SRK that needs improvement. Or at least it needs to be explained so that one doesn't have to rely on trial and error to make the proper fit. Relying on pencil marks and lining things up just right for a dado isn't very EZ in my opinion. I have a method that I've described before, (It's difficult to describe) that eliminates that majority of the trial and error and relying on lining up to pencil marks.
I'm sure you're familiar with one of the methods of making a dado for a shelf using a hand held router. It involves taking a scrap of the same material as the shelf going into the dado and placing it exactly where you want the shelf. Then clamp 2 flat and straight boards tight up against either side of that scrap, clamping them to the surface that will receive the dado. Now you have a template and by using a top bearing bit it's easy to make a perfect dado and it can't help but be the exact same width as your shelf. I can use a similar method, (more or less) when using the SRK to make a dado so that the dado is perfect and you don't have to line up the bit on either side relying on your eyes and a pencil mark.

I would love to see a method of making a sliding dovetail that didn't require one to use trial and error or aligning a bit with a 2 pencil marks. In the mean time, your method isn't any harder than the traditional router table method and in fact looks easier in that it eliminates the chance of the wood moving slightly out of place while sliding past the bit and the bit can only travel on one path. Plus, it's safer. Thanks for the explanation. I'll have to put some thought into some way to do this with the same ease that my SRK dado method has. I'm not sure that it can be done though.

Bruce

Bruce Benjamin wrote:

Dale Sudhoff wrote:

Great job Dik. Seems pretty self explanitory to me. The pictures really help for those who can't visualize.

Dale

Uh, thanks, Dale. Nice jab. Keep in mind that the content of Dik's post more than doubled after I made my comments and before you made yours.

Bruce

Bruce the other post you have mentioned weren't on when I made my post, but have since shown up. Jab/roll wasn't meant towards anyone. Just some people have an easier time understanding things being discribed if pictures are attached.

Dale

Dale Sudhoff wrote:

Bruce Benjamin wrote:

Dale Sudhoff wrote:

Great job Dik. Seems pretty self explanitory to me. The pictures really help for those who can't visualize.

Dale

Uh, thanks, Dale. Nice jab. Keep in mind that the content of Dik's post more than doubled after I made my comments and before you made yours.

Bruce

Bruce the other post you have mentioned weren't on when I made my post, but have since shown up. Jab/roll wasn't meant towards anyone. Just some people have an easier time understanding things being discribed if pictures are attached.

Dale

Dale, I was referring to the content of Dik's first post in this thread. After I replied, but before you replied there was significantly fewer diagrams in that first post. He edited it after I posted but before you posted. So of course it was easier for you to understand because you had the benefit of about twice as many diagrams.

That being said, 1) my feelings aren't really hurt, I was just pointing out your your, "jab" at us Stewpid people as a joke. and...2) Even without the benefit of the second half of the diagrams I understood what Dik meant. I was under the impression that in addition to what was clear to me he was also implying or saying that there was some method of cutting the vertical piece without having to creep up on the proper size. Upon seeing the updated version with the extra pictures I realized it was as I understood to begin with and there is no such method.

Bruce

Andres,

The way I'm doing it makes the pin fit the slot created with a single pass of the bit.

Your way, I would have to be sure that the pin is equal to or larger than the slot made with one pass. Then I have to get the slot to be the same size as the pin. I'll have to think about how to do that easily. Any suggestions?

Dale and Bruce,

I apologize for confusing things by editing my original post. I had intended to do it all at the same time, but ran out of time, and had not yet created the explanatory drawings. In the future I will generate everything before I begin a post so this doesn't happen again. It is easier to do he text in an editor first any way, but I get lazy or overly enthused and just jump in and start a post.

I spent this morning finishing, adjusting, and playing with the setup. I realized that since you need to set up with test pieces, it is fairly easy to fine tune the setup to make perfect cuts, which you can then do rapidly and repeatedly as long as the pieces are uniform.

One thing I had to do today, is put indexing marks on the edges of the SRK base to make it easier to align with the center/setup marks. I filed a flat, smooth place on each side, installed a brass setup bit, and scribed a mark on a piece of MDF. I then used a 1-2-3 block lined up in the scribed line to guide a razor knife to scribe the smooth edge. I'll probably make the scribe a little deeper and fill it with paint to make it stand out.

I made a block to fit into the single opening (thanks Burt) in the top platform, that makes it EZ to get the vertical piece to be flush with the bottom of the platform. I modified a squaring stop so that it would not rotate, replaced the knob with a lock nut, and am using it as the stop to set the placement of the vertical piece. I still have to come up with a movable stop for positioning the horizontal piece. I made a bracket to help support the outside of the top platform (I tend to get heavy handed) so that it doesn't droop under pressure, causing an uneven cut on the outside of the pin. It is held on the left side of the left SME with 5/16" hex head bolts and lock nuts.

I'll spend a little more time playing with the setup and working out the process, before I start making drawers. Any and all suggestions are welcome. I want to make this setup be as EZ as possible.

Dik

Dik Harrison wrote:

Andres,

The way I'm doing it makes the pin fit the slot created with a single pass of the bit.

Your way, I would have to be sure that the pin is equal to or larger than the slot made with one pass. Then I have to get the slot to be the same size as the pin. I'll have to think about how to do that easily. Any suggestions?

Dale and Bruce,

I apologize for confusing things by editing my original post. I had intended to do it all at the same time, but ran out of time, and had not yet created the explanatory drawings. In the future I will generate everything before I begin a post so this doesn't happen again. It is easier to do he text in an editor first any way, but I get lazy or overly enthused and just jump in and start a post.

I spent this morning finishing, adjusting, and playing with the setup. I realized that since you need to set up with test pieces, it is fairly easy to fine tune the setup to make perfect cuts, which you can then do rapidly and repeatedly as long as the pieces are uniform.

One thing I had to do today, is put indexing marks on the edges of the SRK base to make it easier to align with the center/setup marks. I filed a flat, smooth place on each side, installed a brass setup bit, and scribed a mark on a piece of MDF. I then used a 1-2-3 block lined up in the scribed line to guide a razor knife to scribe the smooth edge. I'll probably make the scribe a little deeper and fill it with paint to make it stand out.

I made a block to fit into the single opening (thanks Burt) in the top platform, that makes it EZ to get the vertical piece to be flush with the bottom of the platform. I modified a squaring stop so that it would not rotate, replaced the knob with a lock nut, and am using it as the stop to set the placement of the vertical piece. I still have to come up with a movable stop for positioning the horizontal piece. I made a bracket to help support the outside of the top platform (I tend to get heavy handed) so that it doesn't droop under pressure, causing an uneven cut on the outside of the pin. It is held on the left side of the left SME with 5/16" hex head bolts and lock nuts.

I'll spend a little more time playing with the setup and working out the process, before I start making drawers. Any and all suggestions are welcome. I want to make this setup be as EZ as possible.

Dik

Just curious, are you planning on this holding together with friction so that it can be dis assembled or are you planning on fixing the pieces together with glue?

Matthew,

For a drawer, I will use glue. The sliding dovetail gives a good mechanical joint, but glue is required to make it rigid and stable. Wouldn't want s drawer to get loose and sloppy.

Dik

Dik Harrison wrote:

Burt,

I haven't built that part yet, but had thought of doing that. I designed it with two holes to add to the support of the SRK, but that might be unnecessary. I think your process would work great. I'm thinking about how to do a stop/register for the horizontal piece. I need to design it so that the slot will line up with one of the other cuts. Not sure how to accomplish this. Any ideas?

Dik

Dik,

First, my apologies. I overlooked your response.


I think that I would start with setting up the vertical piece so I could do the cuts on it.

Next, I'd do the supports for the horizontal piece. I think I would put in an Adjustable stop between the EZ rail and the horizontal piece. In theory, after I had the vertical setup done, I could adjust the stop so the horizontal piece would be properly positioned.

Burt