Hello again! Here is an instructable about how to make a line center finder jig/marker.

This is easy to make and easy to use. A very nice thing to have in the workshop or if you are doing some construction work.

How it works

The jig/marker is used to quickly find the center of a board or workpiece and trace a line. This is especially useful if you are resawing, splitting or wanting to put nails or screws in the center of a board.

When you twist the marker, the dowel pegs will register on the edges and make the pencil follow the exact center of the work piece.

Before we start

If you like to see all the steps in moving pictures, there is a small and short video about how I made the center finder jig here.

This project took under an hour to make. Doesnt require many tools and suits beginners.

This idea is not mine and there are many center finders out there. This is just how I made mine. You can adapt and change yours as you se fit. Here are some cool instructables that I have found about making center finders :

By mobilow (3D printed)
By Phil B
By superthunder bolt

Grab a coffee and let's get started...

Step 1: What You Need

I made a layout of all things I used this time. In my video I might use an adaption of the tool, but you can go about however you like.

Materials

Wooden strip (about 12 cm long and about 0,5 cm thick).
Wooden dowel (I used 10 mm)
A pencil

Tools

A ruler
A square
Drill with 10 mm drill bit and a 7,5 mm drill bit
Wood glue
Sand paper
Pen
A saw (to square of the wooden piece if needed)
Optional awl (or smaller drill)

Oh! And if you dont have any dowels? No worries! You could use a nail, screw or make your own dowels! Either check out my other instructable or this little video of the dowel maker. :-)

Step 2: Finding the Center

I start by finding the center of the wooden strip. This will be where the pencil be mounted later. Be very careful when you make the marks, because you need to get the center right and the distance to the dowels exact, otherwise the jig will fail.

I trace a line from corner to corner. This way I dont need to measure anything and where the two lines cross, there is the center of the work piece.

Step 3: The Layout

I then use a square and make a line down the center (If I had a center finder jig I would have used it here!) :-)

The line is only so that I know where to put the center of the dowels later.

I measure 5 cm from the center on each side.

Step 4: The Markings

Here you can see the dots and layout.

Be very careful when you make the holes in the next step.

Either use a smaller drill bit to make a pilot hole, or an awl in each of the 3 dots.

Step 5: The Holes

Drill the holes. Be careful and exact!

I had a hard time finding a 7,5 mm drillbit. 7,5 mm seems to fit most pencils perfect with a snug fit.

The two holes on the sides is drilled with 10 mm size drill bit.

Step 6: The Dowels

You can buy readymade dowels or you can make your own. :-) Either check out my video here on how I made that dowel maker or this instructable here.

I cut the dowel to about 4 cm long and glue them in place.

Step 7: The Result and Final Words

I hand sanded the jig. If you feel like it, you can make a small roundover on the edges. Doesnt affect the functionality, but feels better to the touch when used.

How to use the center finder jig

Well. Place a sharp pencil in the center hole and place the jig over your work piece. Twist it until the dowels register to the edges and trace along the piece. Please note that when the end is reached you cannot make the line all the way to the end of the work piece. Just use a straight edge or a ruler if you need to complement the line.

In the end of the video you can see how I use the jig.

The end

Thank you for reading this instructable. It was fun to make. Please consider to follow me here on instructables. It will fuels me to create more and better content in the future! Please leave a comment below and let me know what you think, or if you have any question. I will try to answer asap.

Here is that video again, if you want to see everything animated and in motion.

Thanks again - have a fantastic day!