Hi thought I would share my Halloween project a ‘Lolly Launch Tube’. Basically it 1000x100mm PVC tube, a 45degree angle connector, programmable RGB strip, PIR sensor, 12v large solenoid, 5v relay and Raspberry Pi PIco W micro-controller.
Not being a mechanical(or any kind of) engineer it is a bit rough and ready. The trap door is from MDF and ply wood, the activating arms are made from 10x3mm aluminium strip drilled with 3mm holes to lighten same.
Also 3/8" threaded rod for the fulcrum. The other fittings are from the same aluminium strip, brackets to hold the tube to the base board, connecting bracket on the trap door and the fulcrum bracket.
The Pico has been programmed to run an RGB light show until the solenoid is activated by an ISR triggered by the PIR. When triggered the trapdoor is dropped sending the lolly down the the tube to the eager Trick-or-Treater. Additionally the light show change to a three led chase sequence down the tube.
Things I have learned:-
- I am not a mechanical engineer.
- The PIR is not the most reliable sensor for this application. A microwave sensor is possibly a better choice.
- A feed mechanism would much better solution than the trapdoor. Limited time, limited mechanical skill and the need accommodate different size and weights of lollies make a hopper system impractical. I have in mind some of conveyor system.
- Sound effects, the silent device lacked a dimension. Appropriate sound effects will enhance the experience.