A motorized trolley

As my new bird house is approaching completion. With a ceiling height of 3.5m, a motorized trolley platform reaching up to nesting areas for installation work is handy. It is useful for harvesting and service failed tweeters in future too.

Some time ago, I saw this mini-hydraulic platform at a Melbourne shopping mall - for hire!















Hmm.. wouldn't it be nice to have one to harvest my bird nests? That is certainly wishful thinking!

So this became another DIY project I have been cooking in mind for the past weeks. The implementation idea actually came from my neighbor, P'Wah. He was contracted recently to wire the sound system of some new bird houses. To save him trouble climbing up & down on the wiring job, he built a motorized platform to mount his ladder on.

I took his idea further to have a more secured platform instead. The basic design looks like this. I'll add a few ladder steps during fabrication. You might want to do the same if you have a fair size bird farm building with high ceiling.



















What motor drives & control did he use?
I caught up with him a week ago to learn from his exercise. He is very helpful to share and I expressed my gratitude to him again here.

He used 2 x windscreen motors (12V DC with built-in reduction gears). Use the ones for trucks if you need more torque, he advised. Those are 24V DC. Like a front wheel drive arrangement, one motor each side. The rear wheels are free turning.

The driving wheel shaft is supported by 2 bearings. A rubber coupling serves as a universal joint between the motor & wheel shafts! Simply clever! I'll try to get a picture of it in future.

A typical automobile windscreen motor.













What about the direction control? Joystick I would thought.
"No, I use one finger", showing me his index finger as he replied.

His solution is genius! He mounted 4 micro-switches (one as seen below) with the lever tab facing each other orthogonally (a square arrangement) inside a box. Cutting a round hole, he can put his finger in to trigger any switch to steer the trolley, effectively like a joystick control!
Hmm.. a photo illustration here will be clearer & do away with such cumbersome explanations!
















Each micro-switch is wired for the 4 directional controls:
1) Forward
2) Reverse
3) Turn left
4) Turn right

This is really neat! I could work out the relay controls from there. It is my good fortune to know such resourceful people around.