This easy to build height gauge for a router or a table saw is much easier to read than conventional ones and the precision is + - 0,1 mm.

It increases the display by a factor of 10 or more.

You can build it in an afternoon and the cost are under $ 2

To see all step at once, please watch the video

Material:

2 thin stripes of wood
1 little piece of plywood
1 little block of hardwood

a plate of MDF
a short piece of a 2x4

a piece of paper
a needle
6 small nails

Tools:

table saw
drill
hammer
Spray adhesive
Super glue

Step 1: Preparing the Long Arms of the Lever

Cut two thin strips on the table saw. The length is in my case about 12 cm. But you can make it longer How long does not matter.

Lay a thin strip on the other and drill a hole at one end

Insert a nail through both and drill a second hole on the opposite end.

The third hole is near an end. The ratio of the long and short side should be about 1 to 10. However, this need not be very accurate.

Step 2: Preparing the Short Arms of the Lever

In my first try I used hardwood but this was not a good idea. Plywood is much better here. So take a little piece of plywood and drill two holes on the ends.The dimensions doesn't matter! The holes should be a tiny little bit smaller than the nails you have.

Use this part as a template for the holes on the back board and the second short arm, the thick one.

Step 3: Glue a Needle On

The short, small arm got a needle as a pointer. I glued it on with super glue.

Step 4: The Back Board

The back board is a piece of MDF screwed on a piece of 2x4 and covered with a piece of paper. The dimensions doesn't matter but it should be bigger than the lever.

Drill two holes near one edge (ca 5 mm) for the lever. Use the short, tiny arm of the lever as a template.

The thick, short arm must have his highest position and the arms have to be parallel.

Step 5: Assembling

I put small washers between the moving part and hit nails in. Where they were too long, I cut them off with a pair of pliers and sand them off.

Step 6: Add a Extra Weight

My fat, short arm was too light. That's why I glued a little weight on it. If you make this part longer then you do not need this weight.

Step 7: The Scale

The setting of the scale is very simple. I put my drill under the right fat, small arm and made a line on the paper on the left. A 1 mm error on the left side is only a 0.1 mm error on the right side. This is exactly enough for woodworking.

Step 8: Increase the Range of the Gauge

In order to enlarge the area of the measuring instrument, I sawed three pieces of scrap wood with a thickness of 1 cm, 2 cm and 4 cm. To avoid errors caused by wood shrinkage, I sawed it like a end grain cutting board.

(I hope this sentence make sense, if not please let me know in the comment section below)