Automatic gate opener
Chris Peck
Otumoetai College
Year 13 Technology: full year project
Teacher: Ian Watson
Chris's clients were 'sick and tired' of getting in and out of their car every time they used the gate on their large lifestyle block. Chris's challenge was to make a gate that could be opened and closed without them having to leave their car.
Chris consulted with his clients extensively and they agreed that a remote control unit would be the best solution. He also established that the gate had to be strong enough to provide security to the property when the clients went away but light enough to be powered by a low voltage power source even in high wind conditions. His clients wanted a double gate so two motors would be required. The upside of this was that each motor would require far less torque than a single unit. Chris trialled garage door openers but found their mechanisms overly complicated. Chris's teacher suggested car wiper motors as a simpler alternative. Trademe and a local car wreckers provided the two wiper motors and both proved powerful enough to move the gates even in strong wind conditions.
For the gate openers, Chris came up with several designs before deciding on an electric ram with an outer aluminium casing that contained an interior sliding rod of stainless steel. With all electrical components encased inside, this model suited his clients' aesthetic demands while protecting the interior circuitry. An easily removed pin also provided a simple and foolproof manual override. Chris found the construction of the opener to be both the most rewarding and challenging part of the project.
"I had very little knowledge on how to make a lot of the parts for the gate openers, so most days I had to learn new skills, which was fantastic. The most difficult part for the openers was making the plugs at the end of the casing as they had to be machined with great precision to allow a snug fit into the tubes. The plugs also needed to be fitted with o-rings to seal the tubes which turned out to be a major job as each one had to be individually trialled and tested."
Powering the openers proved to be far more difficult than Chris had anticipated. After looking into several renewable power sources that were either impractical or prohibitively expensive, Chris was ready to scrap this idea and looked into extending mains power from the house; an expensive and potentially dangerous solution. Fortunately, a local electronics firm let Chris know about an affordable solar panel they stocked that could easily power a seven-volt battery, putting Chris's plan back on track. This firm also supplied Chris with affordable and easy to use circuitry and remote control units, making all the components of his project complete.
To put all these elements together, Chris used Pro/DESKTOP to create a model of the gates. This showed him the best possible placement for the openers, eliminating the need for trial and error and also giving his clients a visual model to work with when making aesthetic choices.
The gate can now be opened and closed by remote, has an easy manual override, and provides security for the clients' property when they are absent. The finished project exceeded all his clients' expectations and received a $500 merit award in the 2008 Transpower Neighbourhood Engineers competition. Chris has since gone on to study mechanical engineering at Auckland University.
Student reflection
I chose this project as I thought it would provide me with a real challenge, and it turned out to be even harder than I thought. I've always enjoyed technology and the chances it gives you to make things like this, while bringing in skills learned in other subjects and applying them in a practical way.
Teacher comment
Chris has gained a lot of valuable knowledge and experience through the completion of this project that is based on more than just technology and engineering. Chris learned intangible real-world skills throughout this project such as using the telephone with confidence, obtaining quotes, decision making and dealing with setbacks and disappointment.
Client comment
We are very impressed with the gate opener. The concept is good and well researched, the opener mechanism has been nicely constructed, and it's totally solved our problem.
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