Measure once...

So I needed to build a polycylindrical diffuser to help mitigate some flutter echo in my drum recording room. I'll be building bass traps and other exciting stuff, but this is the first project of many (or at least until the money runs out).

Initially, I was going to cut arcs out of 2x6 dimensional lumber, but my jigsaw (and my jigsaw technique) proved woefully inadequate to the task. As I tried to follow the curve I had drawn, the saw blade bent out, leaving an unacceptably uneven cut.

Not wanting to purchase a scroll saw (and not sure it would be adequate anyway!) I decided to improvise. Using one metric shit-ton of geometry and trigonometry, I figured out what lengths I'd need to cut small pieces of wood to approximate an arc from a circle with a 4-foot radius. I cut my 2x6's into pieces 1.75" high, cut them a million more times, and assembled this frame:

You can see there's one 2x4 down the middle, with a little pyramid-like stack of boards I cut from the 2x6's. I also cut a 1x4 strip with a 45-degree bevel on one edge; that's the piece on the long side of the frame.

This design has the side benefit of making the whole rig somewhat lighter as well.

Here's a shot of the strip that will hold down a piece of hardboard on either side of the diffuser:

And here's what happens when you select a 1x4 with a great big knot in it:

However, with a backing board and several deck screws, it's like the Good Lord never put that knot in there. Ahem. Plus, it will make a great place to hang microphone cables when it's done! Yeah!!

Here's a stack of the little boards before I painstakingly screwed them all into place; it's slightly easier to see the individual boards when they're just loosely stacked on top of each other:

I proceed to painstakingly construct a total of four of these little piles of joy, one for each rib:

...and then put the pre-cut piece of hardboard in place:

After tucking in the left edge, here's the finished product. Note how the stack of wood supports the curve just so. It's so very close to perfect that I'm beside myself with pride...and we know what that comes before.

Here's the bare wall that's causing me so much grief next to my drumkit. Notice that the ceiling is EIGHT FEET HIGH, but that the rafters are NOT EIGHT FEET OFF THE GROUND. You've heard the expression "Measure twice, cut once?" Well, yours truly, who up until now you might have thought was pretty clever what with those stacks of wood that create supports for a curve of a predetermined radius, NEGLECTED TO MEASURE ONCE. My diffuser is eight feet tall; my rafters will only accommodate objects less than 7 feet tall.

Here's what it looks like when you realize you have to cut a foot off the top of your fucking perfect polycylindrical diffuser:

But it's easier to cut off the top of it than you might think, and all's well that ends well. Here's the finished product, in place and making my drums sound wicket ahsum:

Now it's time to build a 2-foot radius model! I'll post a photo of that when it's done, if I manage not to kill myself with the power tools involved.

Remembrance of Things Chemical

OK, I'm going Proustian!

Playing space invaders in that little arcade room in the back of Sears after school in the old brick St. Brigid's school building. Buying my cub scout numbers from the little bins in the part of Sears next to the stairs. Buying loud Miami Vice shirts from Moeggenberg's men's wear. Buying "cream horns" from the bakery on main street for Mary Battle and eating the sugar crystals first. Pizza Sam's and the scary looking fire escapes on the back of the buildings on Main Street. Bicentennial fire hydrants. Feeling like the 80's were the 50's due to some powerful magic in Alden Dow's architectural byproducts. The pine tree in the woods in the undeveloped land across the street from which I could see the water tower and the presbyterian church. Banana seats. Gray skies all winter long, and thinking every winter would bring a blizzard. Getting alone at the chippewa nature center. Peaches covered in dew from the tree in my backyard (which have spoiled peaches for me forever). The exquisite sensation of wool-polyester-blend cheerleader uniform worn by the occupant of the desk in front of me accidentally brushing against my bare knee. Sugar Springs. Feeling relieved to know that we were high on the list of targets in case of a nuclear war and would most likely be vaporized instantly. And driving around endlessly for fun.