Daniel Mapp
Possum plucker
Tauranga Boys' College
Composite Years 12/13 Product Technology
Teacher: Steve Ronowicz
Daniel traps and skins possums, then sells their fur to companies supplying possum fur for the market. The price they pay depends upon the quality of the fur, and obviously the more fur, the more money.
Daniel decided to use a fellow possum trapper as his client and work on a device to pluck the fur. His client was using one hand to hold the carcass and one to pluck the fur. He wanted a more efficient method of plucking the fur; one which would be faster, would pluck only the longer fur which the buyers want and which would prevent loss of the plucked fur in the wind.
After consultation with his client, Daniel investigated using a machine plucker which would be faster than doing the job by hand. He researched what was available on the market. These machines are run with petrol, which would necessitate keeping a petrol can handy, and are quite noisy which could scare possums away from the area.
They had decided that an electrically run machine would bypass some of the problems and that Daniel would design one which would sit on the back of his client's truck. However this also had a drawback - the need for a generator. The other problem with machine plucking is that it takes the fur so closely that some of it is poor quality, which buyers will pay less for.
Daniel then went to work on designing a device which would enable the user to pluck the fur by hand faster than at present, and that could be carried to the possum. It is much easier to collect fur from a warm possum which meant taking them back to the truck would lead to more work.
The plucker would need to be a suitable size and weight to carry through the bush, and would be required to collect as much of the fur as possible as it fell.
Daniel decided to make a frame which would hold the possum, this enabling the user to work with both hands which would speed up the process. He chose to use aluminium rods as they could be bent into a square shape. He comments that as well as being more aesthetically pleasing than using welded joins, it meant there were no rough bits to catch on things.
The frame required grips at each end to hold the possum in place. Daniel originally planned to incorporate hinged metal for these, before deciding on rubber and aluminium. However, when the client tested the prototype in its actual environment he found the grips hard to use. Daniel next tried out several versions of a design based on a slot, which the tail and two paws were pushed through. As neither worked well for both purposes he decided to have different grips at each end.
The frame needed to be enclosed so that fur wouldn't fall out. Daniel debated the merits of canvas and mesh, deciding upon a canvas base for durability and mesh for lightness and so that the user could see through it. However, as he advanced his design he decided that the material didn't need to be that robust for its intended use, and made it all from mesh.
The back strap was a crucial part of the design and Daniel and his client decided to go with a single sling which wouldn't be as comfortable over a long walk but would be easier to put on and off than a double sling.
Daniel and his client were pleased with the final product. They thought that it could have commercial potential, although this would depend on non-professionals having a high enough kill rate to warrant buying it, or professionals not already having an efficient method in use.
Daniel was awarded a 2006 New Zealand Scholarship Award for his work on this project.
Teacher comment
"Daniel changed direction at the end of term one," says Steve, "as his original idea was proving unrealistic. This shows that students should not be afraid to change if needed, and that all evidence of practice is valuable, even that which is not ultimately successful. It has blown me away to see the creativity in our boys when you give them the chance to express it!"
