The Roller shutter

I was really keen on having a working roller shutter door on the 'main line'. Initially, the design comprised a piece of corrugated plastic sheet wrapped around a drum mounted on the outside of the doorway. Threads fitted to the edge of the shutter would pass down, under the floor. Then, other options were considered:

1) The drum is fitted with a spring so that the drum rotates and lifts the shutter by default, and an actuator/motor under the layout pulls the door down. The actuator will have micro-switches to limit the travel and should be easy to set-up.

2) The drum is motorised to pull the shutter up, with springs under the floor pulling the shutter down.

3) The threads form a continuous loop and the motor drives the door up and down.

The drum unit was made up, together with the door and frame. Then, a chance discovery of geared motor units on eBay pointed the way forward. A 6v 10 RPM unit was purchased and things fell into place.

Raising the door worked well, but driving it down by reversing the motor caused problems. Various ideas using elastic bands and springs underneath, and guides over the drum all failed. The simple answer was weight - car wheel balance weights, stuck to the bottom of the door.

​The roller door power supply will be set to a lower voltage/speed, in due course. 

​The plasticard box at the door head is purely for show.

To compliment the door, a flashing beacon seemed appropriate. A search online produced a design and after purchasing the components, a unit was made up. It works off a 9v supply, so a separate power supply and circuit was required. The flasher needed to be working while the door was open, not just while the door was operating, so the separate circuit allowed this to be achieved by fitting another micro-switch at the bottom, piggy-backed with the limit switch. 

A block of plasticard housed the 3mm red LED, which was fixed on the adjacent wall. An experiment with 1mm dia plasticard rod proved very successful, which means copious amounts of conduit will be incorporated into the model. To accompany the beacon, a suitable warning sign was sourced, printed and mounted near the doorway.