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Sunday, March 30, 2008

Fun with engineering!

Here is a quick update on the continuing saga of building this lighting valance. I ran into an interesting, unforeseen engineering problem (due entirely to my inexperience). Let’s see if I can explain this...

While installing the front roof slats (starting from the center and working towards the sides), that extend from the front of the clearstory and curve down to the very front of the valence, I discovered that they were fanning out in the front.

I think I know why this is happening. The big arch of the roof requires the roof slats to cover more “ground”. You can see what I mean in the front view photo. The front edge of the roof slats are only required to cover the horizontal distance from side to side. But the back ends of the roof slats are required to not only cover that side to side distance, but also the vertical distance of the arch which, at its peak, is 6” higher than the sides.

So what that boils down to is; the fronts of the roof slats have to cover the 57” from one side to the other side. The back end of the slats that are butted up against the clearstory have to cover 59 ½”, another 2 1/2” further.

Fortunately I was using a square the whole time. So I thought the slats were moving slightly while I was nailing, so I would compensate with a slight gap at the top to keep things square. But the problem persisted until I finally figured out what was going on.

I guess what I should have been doing all along is sanding a slight taper to the roof slats to compensate for this. And that’s exactly what I started doing with the slats that extend clear across the roof. In the last photo you can see that the first full length slat took the brunt of the tapering. After that each full length slat was sanded with a more reasonable taper.

So all I’m saying is, things are turning out a little less than perfect. But really, who the heck is going to notice? Not many. Everybody’s attention should be focused on the layout anyway. After all, the layout is the real attraction. yessir! The real attraction!