This article appeared in an old NZ Rod&Rifle magazine and was written by Graham Henry
A lot of ducks shot every year are wasted. When you are shooting ducks you are too busy to pluck them. That night you are too tired and the next day you have to do to work. A few days later the rotten ducks are quietly buried.
Here is the way to avoid this by reducing the time taken to pluck a duck to about two minutes.
I had seen other mechanical pluckers in action but they had often not worked as well as I thought they should. A few years ago I set out to try and build a good plucker for myself and now I have two. A single-headed model that is easy to carry around in the back of the ute and a double-barrelled model that we take on opening weekend and on shoots where we expect to get a lot of ducks.
I will try and keep the text short and use pictures to show the construction. The basis of the machine is the rubber fingers which are available commercially and are used in the chicken industry. You need twenty. You need a lathe to make the drum that will carry the fingers. A local engineering shop should be able to make one for you in two hours. If you have a workshop and can weld you could do the rest of the work yourself.
Take a piece of 90 to 100mm diameter tube with a 1.6 or 2mm wall thickness. Pipe is too thick in the wall. Cut off a piece of the tube 120mm long and square and chamfer the ends in the lath<;,. Wrap a measuring tape around the tube and divide it into eight equal segments. Scribe longitudinal lines along the tube to mark each division. A scrap of angle iron makes a good guide for the scriber. On one of the scribed lines make a mark 25mm in from the end of the tube and then four more marks at 19mm intervals. Each of these five marks needs to be scribed around the circumference of the tube and the easy way to do this is to chuck the tube in the lathe and rotate it slowly and use the tool post to support your scriber. You now have the drum divided up by eight longitudinal lines and five circumferential ones. On one longitudinal line centre punch where it is crossed by the first, third and fifth circumferential lines. On an adjacent longitudinal line centre punch the second and fourth intersections and continue this staggered pattern right around the drum. You are now set to drill twenty evenly spaced holes to hold the plucking fingers. Use a 3mm drill first, then open the holes out to 6mm. The holes need to end up from 19 to 20mm in diameter and be free of burrs inside and out and it is here that you can go wrong. Use an ordinary three quarter or a 19mm drill and you will probably make a mess of trying to drill through the curved surface of the thin walled tube. You must have the drum firmly held in a machine vice on a drill press or when the drill grabs you will damage your hand. Get a professional to do it for you. The job is best done with a tool called a Cone Cutter that will cut clean holes of any size in thin metal. Take care with the de-burring of the holes as you have to be able to get the rubber fingers through them without cutting the rubber.
To complete the drum take a 100mm square of 6mm flat steel and a 40mm long piece of round steel of 40-50mm diameter. Face the round off square and weld it in the centre off the 6mm flat. Chuck the round and tum off the corners of the square until it is just a couple of millimetres larger in diameter than around a yard or workshop. Stick to the recommended drum size. Much smaller and you won't be able to fit the rubber fingers in and much bigger is less suitable for the size and shape of a duck. Go bigger and you will have to use a bigger driven pulley or your speed at the end of the fingers will be too high.