G'day fellow workshoppers,
Finally got around to designing, building and installing the new auto door for our girls. I was quiet shocked at the price of purchasing a pre-built opener, but I've put together a price list and can understand why these items are expensive. Anyhoo, I will attempt a how-to on this project.
Here are the parts required for the build that I put together. Motor, photocell, double pole double throw relay, timer, transformer, micro/limit switches and an enclosure to put it all in. (The black transformer may be used as an alternative).
I had to make a shaft for the motor so as to lift and lower the door. I decided to use a bolt with a hole drilled in the end to suit the shaft. A couple of very large washers and nuts and a smaller bolt tapped to lock onto the shaft as a key.
Time to put it all together. Wiring is via the diagram attached below. I also decided to install some LED marker lights I had as surplus to come on just prior to dusk and turn off after a couple of hours (photo upside down for some reason). I did a test run at this stage to ensure it worked.
The following is after installing on the coop. The little pulleys allow the door to open/close without binding.
The rope is just plain 'gunline' and is not prone to rotting. I will probably replace this with something more permanent in the future.
Last but not least is the placement of the micro/limit switches which shuts down the motor when either in the raised or lowered position. In this case I used a long bolt and positioned the switches to allow activation.
Here is the wiring diagram. It may look a bit intimidating but it is foolproof.
If anyone wants a PDF version, just let me know. Also if you have any questions, please don't hesitate.
Nearly forgot the price list.
24v DC motor with 48RPM reduction gearbox - $10.80 (ebay)
Photocell - $3.26 (ebay)
Relay - $4.70 (wholesaler)
Timer - Free but can purchase for under $20.00
Transformer - Free but approx $20-30 on ebay
2 x Limit switches - $12.00 (wholesaler)
Enclosure - $32.00 (wholesaler) but can get much cheaper without clear lid.
Cable, connectors and misc stuff - Approx $5-6
Labour not considered (approx 4 hours to put together, test and install).
Considering a pre-made purchased unit costs upwards of $250.00 - $400.00, I think I made the right decision making it myself.
Cheers'n'beers
Daryl
