June 23, 2008

Make your own Stackable Gobos!

Hello everyone! As promised, Here is the article on how to make your own gobos (a gobo? what the heck is that?)

Well here's what we'll be building in a youtube video:

Recipie for 2 Gobos:
cost: about $40 per gobo

Each step covers what to do for one gobo. You need to do the instructions from step 3 - 12 twice to complete both gobos.

  • 16 feet of 1x12 lumber
  • 12 feet of 2x4 lumber
  • 2 - handles (I used cabinet handles)
  • Box of 2" wood screws
  • Fiberglass insulation
  • 2 - 2' x 2' pieces of 1/4" plywood
  • A cover for the absorptive side of the gobo

I used pegboard for my absorptive side. I evens out the frequency response a bit, if you're not sure what that means, my advice is to use pegboard. If you want your gobo to absorb lots of high frequencies the you can staple canvas around the open side of the gobo instead.

You can also make see through gobo's by removing the plywood, fiberglass, and absorptive side cover from the list. Use 2 - 2' x 2' pieces of plexiglas on both sides instead of plywood and an absorptive cover.

See through gobos are useful when you need several gobos to block the sound and you want to stack them without breaking the musician's eye contact.

  • Circular Saw
  • Drill (with a 3/32" bit; A screwdriver bit would also be useful)
  • Measuring Tape
  • Screwdrivers
  • Pencils
  • T - Square
  • Boxcutter

Step 1: Cut the pieces you'll need
I labeled the dimensions of each piece as I cut it:
  • (2x) 2x2 1/4" plywood
  • (2x) 2x2 pegboard
  • (4x) 2' long 1x12
  • (4x) 1' 9" long 1x12
  • (4x) 2' long 2x4
  • (4x) 8" long 2x4

Step 2: Mark the 2' long 1x12's 2.5" from each end. These marks show you where to drill later on.

Step 3: Set up the 4 sides of the box on a flat surface and tape them together. The 2' long sides are shown on the left and right in the picture, and the 1'9" sides are shown on the top and bottom in the picture below.

Step 4: Drill at the places you marked, and try to make sure that the you get the bit centered by the width of the 1'9" pieces. You should end up with 8 holes (2 on each corner). Put a screw in each hole.

The four pieces should make a perfect square with 90 degree corners. Use the T - Square to check this is the case as you go.

Step 5: Put the 2' x 2' piece of plywood over it (it should line up with the edges of the box you've built so far). I didn't need to drill holes before putting in these screws, but if you're worries about it, or using really fat/long screws, it may be a good idea.

Step 6: Now that the box is strong and stable, you can pull off the tape we put on in Step 3

Step 7: Attach the handle. You want to center the handle so that it'll fit nice later on. The end goal is to have it fit between the feet of the gobo above it so that they can be stacked easily.

In this picture, the long 2x4's on either side of the center row (the one with the handle and the shorter 2x4's) represent the positions of the feet of another gobo. Don't attach these long pieces, they're just to help you understand.

Before you attach the handle mark where the holes need to be drilled by putting the handle on it's side. Drill from top to bottom through the marks you just made. Then it's a piece of cake to attach the handle using the screws that come with it (all the handles at Loews came with screws)

Step 8: Cut the fiberglass insulation into 22" segments. If you used 15" wide RC-13 like me, you'll need six segments per gobo.

Cut 2 of the 6 segments in half (as pictured). Only cut 2 of them in half.

Here's what all your cut fiberglass should look like:

Step 9: Put the fiberglass segments in the gobo facing out (each layer facing out, though it doesn't matter a whole lot which way the individual pieces are facing).

Step 10: Attach your cover. I used pegboard because of it's flatter frequency response. You can use canvas if you'd like to tame those higher frequencies, or if you just want to block sound with minimal absorption just put plywood on this side as well.

note: there is no insulation in the picture. This is just because I'm dumb and took the picture at the wrong time ;). Don't take the fiberglass back out of the box.

Step 11: Attach the feet. The feet are necessary to make the gobo's stackable. Again, I didn't need to drill before putting in these screws. However I did need to put the screw in, take it out halfway, and put it in again (to get a tighter fit).

Whatever you do, just make sure you put the screws in far enough that they're somewhat inset into the 2x4. You don't want the screw sticking out, or else it'll be wobbly and also scratch wood and tile floors.

Keep in mind that these need to be all the way to the edges, because the handle and alignment 2x4's need to fit in between them.

Step 12: Attach the alignment 2x4's on the top.

Sorry to use the same picture twice, but this one is the best shot to illustrate the point. You want to attach these alignment 2x4's so that they're in line with the handle with space for the feet of the next gobo, which would be on top of it.

Steps 13 - 15: Admire your handiwork!

I hope you found this howto guide useful! I've also created an instructable of this guide.

© 2008 Jim Robert