Mechanical Seven Segment Display

Important: There is a new version that uses only a single camshaft. You should use that version instead.

This is a mechanical seven segment display that counts from 0 to 9 using a pair of camshafts.

Non-printed parts

• 4x Square M3 Nuts
• 4x M3x6 screws (or longer)
• Plastic glue (it will work without glue, but relies on gravity and friction to keep things in place)

Printed parts

• 1x Front plate
• 2x Side plate
• 2x Bottom Plate
• 7x Segment
• 2x Pusher Right
• 2x Pusher Left
• 3x Pusher Center
• 7x Pusher Pin
• 1x Camshaft
• 1x Camshaft Counterpart
• Optional: Knob. The unit can also be driven with a Lego Technic axle

Printing

The camshafts should be printed standing up with supports (I used organic supports). Everything else can be printed laying flat without supports.

Assembly

1. Insert four square M3 nuts into the front plate and glue them into place
2. Put a pusher pin into each pusher plate and glue it in place.
3. Connect a segment to each pusher as shown in the photo.
4. Put the segments into the front plate.
5. Attach the side plate on the side where the pushers don't have an opening and screw it into place.
6. Place the two camshafts between the top and bottom plate and make sure that the arrows at the top of the camshafts line up.
7. Insert the camshaft assembly into the unit.
8. Attach the other side plate and screw it into place.
9. Attach the knob