Unfinished Purple Martin Design Project

[johnt]

Here is a project we worked on for a long time, but just didn't turn out like we thought. See if we get any feedback.

An illustration of a purple martin house on the inside cover of a bird book by Gilbert H Trafton inspired us to draw and build a similar one. It's a little complicated and our drawing plans never came close enough to follow through with constructing one, and we're just getting around to trying again.

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The difficulty lies in the roof ridge inclined from center to outside. We first made the front walls wider than the back walls, which spread the side walls apart further in the front than in the back. This raised the roof ridges towards the outsides, but only slightly. It didn't give us anything even close to the extreme animated cabin look and it created a nightmare of complicated dimensions through out. Then we changed the sidewalls back to parallel and inclined the sidewalls but it still did not achieve the extreme look.

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It's difficult to see from the century old book photo, but upon closer examination it appears that each stack of apartments actually has two roofs. Each top apartment has a simple gable roof, possibly inclined to 45 degrees. A second roof made of two triangular sections is attached on top of and beginning near the front of each gable roof and extending further out and up. The top of this secondary roof is angled out further than the bottom so that the fascia is also is also angled out.

This is what we will try next and we're pretty certain this will give us the look we desire with simple carpentry. We also have some ideas on simpler work piece cuts which will be stronger and easier to assemble and will also include the center tower and perches. The center tower could continue from tower top to the bottom of the house and contain several square floors with holes cut to securely enclose the mounting post. We're also looking at attaching the floor holding the perch tower on one side with a spring loaded hinge allowing it to tip sideways when the house is lowered.

Here is what we like about what we have so far:

We really like the easily removed and replaced whole front wall revealing all 4 apartments in each apartment stack. Each front wall is inserted by tipping their tops inside between the sidewalls and slipping them back under, and then up behind a roof rafter. This raises the bottom of the front wall just above the floor. The bottom of the front wall can then be slid back into the house between the sidewalls and dropped down into a slot in the floor only deep enough so that the top remains behind the roof rafter. The slots in which the bottom of the front wall rest into are created by the space between a 1x2 bottom balcony floor and the plywood floor. The 1x2 balcony floors are fixed to the sidewalls

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Easily removed and easily replaced. There are no hinges or fasteners yet it's still secure. We don't think anything short of extraordinary could lift the front face up and out. When the front wall is removed, all four rooms in one column are completely open for easy cleaning. There are no hinges, fasteners, and no front lip or protruding edges to hinder scraping dirt off from the room walls, floors or ceiling.

The predator guards are dowels drilled through the front balcony and wall frame. Larger horizontal dowels fit through holes drilled in the sides of the front wall frame. Vertical dowels fit through holes drilled into balcony floors and horizontal dowels. The top horizontal dowel is fixed to the vertical dowels and together could be left loose in holes of the other dowels and floors. Dowels are secured into place when the front wall is inserted into place. Fixing with glue or other means is an option but might make it more difficult to replace.

Wind is a potential problem. This design has a rather large profile (maybe most do). It might be possible to cut out gaps in the secondary roofs near where they come together at the peak of the primary gable roof. The secondary roofs are pretty much just cosmetic and the gaps might not even be seen. Allowing air-flow through the gaps might relieve some wind pressure.