Anyone who has worked wood for a long time has tried to make a groove to fit another piece of wood.

But no matter how well you measured, you soon realized that in this way, it is practically impossible to make the perfect groove. 
Either the groove is too narrow or too wide.
So you can never get the piece of wood in it, or the wood falls out faster than you can put it in.

If you really want the perfect groove, you will need an attachment that can help you with this.

If you live in a country where it is not allowed to use a dado blade on your table saw, the Kerfmaker is the perfect tool for this.

If you search on the internet, you can easily buy a kerfmaker for a reasonable price, like this TIPU kerfmaker.

An alternative is that you can make this kerfmaker yourself.

That’s what I will show you in this blog.
With the free plans you can download on this page, you can create this DIY kerfmaker yourself.

Before we dive into the blog, you can watch the video first.
In that video, I will show you how I build my kerfmaker.

In the blog post underneath the video, I will describe step by step the actions you need to take to make this kerfmaker.
I will also list the materials and tools you need for building this project.

Building the kerfmaker step by step​

Now that we have gone through the list of what we all need for this project, I will explain step by step how to make this DIY Kerfmaker.

Let’s go!

Step 1 | Preparation

To make this kerfmaker, I started by drawing out all the pieces I needed on a piece of scrap plywood.

The correct dimensions can be found on the downloadable free plans.

Step 2 | Cutting to length

Once I had drawn all the pieces, I could cut them. 
I cut the pieces a little wider than the marked dimensions.
This way, I can trim them flush at a later stage.

Because this is about cutting small pieces, I chose to work with my crosscut sled.
It is not only much safer to work on, but also very handy and fast.

Step 3 | Glue up & trimming

Once all the pieces had been cut, I glued them together. 
By using very fast CA glue, I was able to significantly reduce the waiting time for drying.

If you do not have CA glue, you can use wood glue.
Please note, clamp the pieces well together and respect the drying times.

Definitely consider purchasing a CA glue and accelerator kit. 
This is recommended for projects like this.

The pieces were connected immediately, making the work much faster. Also, the displacement of the pieces relative to each other during gluing is hereby reduced.

Once I glued all the pieces, I trimmed the pieces so that the sides were perfectly flush.

Step 4 | The knobs

You can also easily make the knobs with which you can set the kerfmaker yourself.
I’ll show you how I did it.

Preparation

In preparation for the knobs, drill the holes in the kerfmaker as indicated on the free plans.

To be able to screw the knobs and block the kerfmaker in the correct position, use T-nuts that you insert in the drilled holes.

Preferably, you can press the T-nuts into the wood instead of hitting them with a hammer.
This will reduce the risk of splitting the wood.

To press these T-nuts, I used my vice for this.

Making the knob​

To make the knob I took a piece of scrap wood on which I drew a circle.
I divided this circle into 8 equal parts.

I drilled holes at the intersections of the lines with the circle.

In the center of the circle, I drilled a hole halfway the thickness of the wood. 
For this, I used a drill bit just smaller than the head of the bolt.

With a hammer and chisel, I made the central hole just the same size until the head of the bolt fitted perfectly.

I connected the bolt to the wood with CA glue.

After the glue dried and the wood was firmly glued to the bolt, I trimmed the sides of the wood.

I did not cut deeper than the center of the drilled holes. 
With a little drill press hack, I took the rest of the wood away.
By spinning the wood and pushing the sanding block against the wood, I had the perfect circle.
If you want to see more wood sanding tips, check out the article — 7 effective wood sanding tips — that I wrote earlier.

After updating the knob with a round file and sandpaper, it was perfect to use for the kerfmaker.

Step 5 | Assembling​

Now that all the parts were ready, I could slide them together and clamp them with the knobs.

Do not forget to use a washer when you mount the knobs.
That washer will distribute the pressure of the button when clamping, and ensure that the kerfmaker cannot move.

How to use this kerfmaker​

Working with the kerfmaker is actually quite easy.

With the outside of the kerfmaker, I can determine the thickness of the saw blade. 

I use my square for this, which I place against the saw blade.

On the other side of the saw blade, I place the kerfmaker and push it over the saw blade against the square.
By now tightening the knob, the thickness of the saw blade is set on the kerfmaker.

By turning the kerfmaker over, and placing a piece of wood between the other opening, I determine the thickness of the groove I want to cut.

By determining the position of the first cut, the kerfmaker and the stop block can be placed.

Secure the stop block and do not move it while cutting.

By flipping the kerfmaker over and placing it against the stop block, the second cut is automatically determined.

After sawing the inner and outer cuts of the groove, you can cut out the rest of the groove.