The completed 14 degree marker

I also made a 10 degree marker. 

So how do these work? Well they allow you to mark both faces of the board exactly without worrying about connecting lines. You have a straight surface, and an angled one. If you cut tails first, this is how the marker is used

If you cut pins first, this is how the marker is used 

I'm starting with a thin scrap of Bubinga I had left over. This wood is great for this project because it's really hard and really dense. It's also very stable

I've used a lot of dovetail makers so I know what I like and don't like. I don't like really wide markers. My sweet spot is 1 1/4" wide. I would suggest this as a starting point. Some people do prefer them wider. Here I am laying out a gauge line to rip the stock to

The stock is now ripped to final width and the edges are parallel        

Time to square an edge. I am trying to stick with hand tools for these 101's so I am doing this at the shooting board. A miter saw or tablesaw sled would make very quick work of this (and the next few steps). 

I need to cross cut off a portion for the rear support of the marker. It's important to know the size of stock you generally work with as you want the part a tad longer than the thickest stock you'll be dovetailing. I cut mine to 1 1/4"   and set up for a first class cut at the bench hook

Once that is cut and the end grain is square (either off the saw if your lucky or at the shooting board if you're not), I mark out the location for the dado. This starts at 1" from the top. This is not a critical measurement, go with what you like. 1" is enough for me to hold it firmly during use.

I mark this line with a knife

I then use my other piece as a reference and lay it over my knife line. I draw a line with a pencil on the other edge. NOTE - this is just an approximation, Do not knife this in or chisel to it or the dado will likely be too large 

I then set my marking gauge to about half the thickness of the stock and score between the lines for the floor (bottom) of the dado

Using a bench hook for support, I chisel into my knife line from the center of the dado. I chisel in a bit then chop straight down the knife line until I get to the bottom

Now that I have a bit of material removed, I seat my piece into the dado to mark the final location of the other edge    

And I chisel from the middle to that knife line just like above leaving a ridge in the middle    

I witched to my other bench hook with the 1/8" tall fence and remove some of the hump with a chisel 

Then the router plane takes care of the rest. If you don't have one you can proceed carefully with the chisel. This is a very small dado. Or you can make a "poor mans router" a la Paul Sellers. It's important the floor be even. This is a reference surface for your dovetails

Done. I work the router plane down to my scribed depth line

Test fit - pretty good

It should be loose enough to bang in with just your hand (no mallet needed) but tight enough to support the other piece without glue. Too tight and it risks splitting, too loose and the glue will hold it, but getting it square will be impossible. 

Transfer the mark from the part of the dado closest to the bottom all the way around the piece

Get a protractor and set your desired angle. This protractor sucks. I used it because it shows the angle well on camera. I primarily use 10 degree and 14 degree dovetails. here is the 14 degree marker    

I have a piece of scrap plywood the same width as my marker. I draw the angle on that and cut it out. Like with the rip cut, I saw a bit proud of the line then plane to the line after

Done

Now I transfer the angle to the marker. I need 3 hands to take a good picture of this, and I only had 2 available - so use your imagination. I put the square on the line I transferred around the piece, then put my plywood template against the square. Flip and repeat

Like with the plywood, I cut the angle then planed to the line. 

I cut a little bit of length off to square the edge and remove the fragile point. The overall length from the dado is 2"

Now time to test it. It's important both sides match. I insert the rear piece into the dado without glue and transfer a mark to some scrap. I then cut the scrap proud and plane to the line

I test it against one edge

The flip and test against the other. If there is deviation, work the proud edge down with sandpaper or a plane. If you want to leave the deviation, it's not the end of the world. Your dovetails won't be perfectly symmetrical - but that's a part of the charm of hand cut dovetails. I prefer symmetry over charm, so I tuned mine up

Now I rough up the back with 80 grit paper. I want some friction here

I chamfer all the edges that will not be referenced when laying out dovetails. You just want to very gently break the edges you draw lines against

Since I am making a few of these, I put a contrasting dowel in and stamped the angle

Glue and clamp the pieces together