# How to use trammel heads to mark off distance increments?

It may be necessary for you to divide a line up equally into a number of increments. Trammel heads enable you to do this very easily.

### Step 1 – Draw line

Draw a line onto your workpiece.

### Step 2 – Install pencil or metal point into trammel heads

Install either a pencil or a metal point into each of the trammel heads.

### Step 3 – Assemble beam compass

Assemble a beam compass by attaching one trammel head to the end of a ruler and setting the second trammel head at the required distance away from the first.

The distance between the trammel heads will depend upon how long you want the equal sections of the line to be.

E.g. If your line is 1m long and you wish to divide it into 5 equal sections, the distance between the trammel heads should be 20cm.

### Step 4 – Draw an arc

Position one of the trammel heads at the beginning of the line.

Draw an arc across the line using the other trammel head, indicating the the first increment on the line.

In our example, the arc will have been drawn 20cm from the start of the line.

### Step 5 – Mark off increments

Pivot the beam compass so that the second trammel head is in front of the first. Draw an arc across the line once more, marking the second increment.

Swing the beam compass from one point to the next, marking off each increment, until you reach the end of the line.

Your line should now be divided into a number of equal increments.Note: It is important to set your trammels as accurately as possible to avoid accumulative error.
Any error in the initial set-up will accumulate for each successive increment.
In the example above, if your trammels had been set to 20.1cm (201mm), 10 increments would mean that you would end with an additional 1cm.