'Breakfast is served'All rights reserved, by David (Flickr)

A reel good job

A new reel design would reduce the time and energy required to erect and remove temporary electric fences.

Farmers use temporary electric fences to manage how much winter feed their stock have access to each day, to ensure that the feed is efficiently consumed rather than trampled. Every day farmers have to manually shift these makeshift electric fences. One of our Mechanical Engineering learners has developed a retractable plastic housing that can be used with different brands of fence reels, to make it easier to put up and take down an electric fence.

The plastic housing holds a torsional spring that is torqued up with the help of a chuck connected to the reel shaft. When the fence wire is unwound from the reel the spring will become charged and provide a resistance (torque). This torque will then be used to retract the fence wire back onto the reel in a winding motion. All parts are designed around metric measurements and can be found in local hardware stores or online. The material used is durable to withstand the harsh agricultural elements.

The learner designed and tested his electric fence reel in SolidWorks before building his prototype. in our EPICentre workshop facility. The prototype enabled him to test different sized housings and different spring strengths. This final prototype was able to put up 50 metres of fencing and retract it back on the reel in half of the time with less energy required. The final cost of the completed prototype was only $200.