|Project by Roz||posted 03-22-2008 08:05 PM||17876 views||6 times favorited||2 comments|
Spring has come to the Deep South and my mind is on outdoor projects. I have always wanted to build a Purple Martin house but never seemed to be in one place long enough, with the time to do it. Now that has all changed and this is my first attempt. I realized a few weeks ago that I might have time to get one done before the arrival of the Martins. I knew it would have to be done quickly. So I began to search the internet for details on what a Martin house should be and made several discoveries. I found free plans and down loaded them from a Purple Martin website.
In my reading I discovered that the nesting space was typically 6 inches square but 7 inches was better. A 4 inch wide porch is recommended. The entry hole should be 2 ¼ inches placed 1 inch off the floor and the entire thing should be painted white but can be trimmed in any color. So I altered the free plans and went to work. I did not like the idea of climbing a pole by ladder to clean a bird box so looked for some kind of design to allow for raising and lowering the bird house. I found only one “break over” pole design which looked over engineered and complex. So I came up with my own. It seems to work well and requires only a pulley, some rope and boat trailer hoist, which I happened to have lying about.
THE HOUSE Following the plan I used ¾” stock. I lined the air shaft created when the interior dividers are made with a sleeve of ¾” material. I made it 6 inches longer that the house was tall. It was a 7 inch square tube. I added vertical cleats on the inside to reduce friction and allow for movement up and down the pole. This also provides a solid attachment point for the rope and a path of travel from the pulley to the hoist. It still functions as an air shaft as well. The dividers and floor/ceiling pieces stacked together over a sleeve like toy blocks. The dividers and outside walls were made from 1X8 and I used the full board width instead of cutting them to 7 or even 6 inches, which would have saved on weight. I attached each level to the sleeve. I screwed the outside walls together at the corners. Each space is vented to the central air shaft. I used Hardy Board scraps from building my shop for the roof.
THE POLE I got the longest pole I could find locally (12’) and added about a foot when I made the inset for the pulley. I cut a taper on two opposite sides of the post top. On the other sides I cut rabbits to receive pieces of 1×4 and did the same to a block attached at the top. I hung the pulley from the block by two eye bolts at built a decorative cap. I mounted the hoist at about 3 feet from the other end of the pole and put it all together. I made a swing arm of 1×4 to raise up when the house is at the top of the pole. I used carriage bolts for the hinge and to hold the swing arm in place. A wing nut secured the swing arm. Then the tension could be released from the hoist and rope and the weight of the house is carried by the swing arm.
WHAT I LEARNED
The resulting box was quite large and heavy. I followed the plans and used ¾” stock. After having built it I could have saved a lot of weight by making the interior dividers from 1/8” luan and treated them with a sealer. The floor/ceiling boards could have been reduced to ¼” plywood with the exception of the very bottom piece which must support the houses weight. I could have reduced the height of each level to 6 inches reducing size and weight.
Luckly for me this project required no special skill. In spite of its weight, it all seems to work fine and should last for many years. I have received many compliments on it. It is popular with the local citizens.
Now if I can just get some birds!
Terry L. Roswell
-- Terry Roswell, L.A. (Lower Alabama) "Life is what happens to you when you are making other plans."