This project is designed to help pupils understand just how accurate the laser cutter can be.

The accuracy of holes that the drills sit in by their nature are simple to understand but the little addition to this design is the two channels that run alongside the holes.

These channels are exactly the same size as the hole they sit next to and they operate as a sizing guage removing the need to either measure it or reading the size off the shank.

All you do is push the drill in the slot at the thick end and then move along until it stops, the drill is now adjacent to the hole to which it belongs. If you have never seen this type of grading before it is remarkable.

The same system can be used as a stand alone template to measure drills thus reducing the number of digital calipers or micrometers that need to be out in the workshop. Should I re-make this project I would not machine the four slots in the backing wood I would just run two relief slots for the measuring steppers.

The actual drill holes I would drill after the template is affixed using the template as the hole location, this would ensure the drills sit upright when parked. I include the sales video for laughs at the american sales technique but to also inform pupils that these sets exist I have one myself in the UK, the letter sizes are all but forgotten outside engineering circles, in America it is worth pointing out that metric sizes are the oddity, the UK moved over to metric sizes in the mid 1970's America still works on 12inches to a foot, three feet to a yard, which is a crazy system if you have never encountered it.