96” x 1” led, laser, or lcd screen?

I am looking to make a 96” long layout device that will connect to a number keypad, computer(Maybe arduino uno?), and light up at each mark point.

We do a lot of hand measuring and laying out marker lines on straight thin (1”x 3/8”) pieces of metal.

Each piece is a different custom size and needs to be split into even increments and marked for weld points.

The idea is: You punch a number on a keypad. The computer takes that number and divides it into preset increments, and then engages light or marks at each point. Then I mark the point on the metal where the lights are. And thats it.

The mark needs to be pretty accurate (within 1/8”), so if it was led, it would have to be small lights very closely spaced I am thinking. A 96” lcd screen with just a line on it (instead of light) would work fine too. Laser maybe, but I don’t know of one that could do this.

Any help or direction would be much appreciated.

Idea #1
A linear rail with a laser pointer mounted on a carriage that traverses the rail. [one axis of a CNC machine]
The carriage is on a belt/screw driven by a stepper motor.
Target is aligned under rail, after increments are computed the laser pointer traverses the rail stopping at each point so the operator can make a mark.

Note: If you had a big enough x/y cnc machine it could be made to etch a mark anywhere on a metal sheet that was laying under it. This would probably be overkill.

Crazy idea #2:
A powered tape ruler is fixed at one side of the work surface. The ruler is stepper-driven. The controller feeds out the ruler on the surface the full length of the target. The ruler retracts a distance that is equal to each increment whereas the operator makes a mark at the end of the tape.

Crazy idea #3:
A 96" rack lays in a slot on the bench. At one end of the rack, a stepper-driven pinion drives the rack left/right. The controller feeds out the rack in the slot the full length of the target. The rack retracts a distance that is equal to each increment whereas the operator makes a mark at the end of the rack.

This could be made to fit in a slot on the work surface or in a form that could lay on top of the target


put a little servo on that 96" long X axis carriage and have it mark the points.


Thank you both for your ideas. I really would like to figure this out using led’s or lcd screen connected to a computer. Trying to keep moving parts to a minimum and I don’t have cnc.

you could connect a gear upto the center of the tape measure, put an encoder on it and then a batter powered LED with light-piped pointer mounted on the end of the tape measure. Would have to calc decreasing radius as the tape measure was pulled out but the LED could be controlled to light at specific intervals. Wireless control of the LED would be an upgrade option.