Sunday morning I had “afterburner” on the brain 🙂 I had been thinking more about the design of the afterburner and how I could make it more interesting to look at and provide a nice bright afterburner glow. Also how it would all come together to be mounted. The size of the speaker enclosure that I created templates for on Saturday was going to end up being based on how large of an inside cylinder that would end up inside the afterburner turkey feathers.
I had to decide if I would simply place the speaker enclosure inside the turkey feathers, or create an inside cylinder that everything would go inside of. So I started searching around on the web for pictures of afterburners to see if I could find some patterns. What I found was that many of them had an inner ridged structure very much like the picture at the top of this post.
Then it came to me! I remembered that I had material that would actually look great as an inner cylinder and it’s one of the most common household items you’ll find. A galvanized steel garbage can 🙂
I dug this one out of the snow from the side of the house. It’s actually the garbage can that I used for parts on my turbine earlier and was just sitting there. As you can see when you look down into the garbage can it has a really cool pattern; and all the angles will really reflect the lights of the afterburner LEDs! I’ll end up painting everything gloss black so that there’s lots of reflection, but still a dark “inside an afterburner” look.
The diameter of the garbage can was a little large, so I would end up needing to slice it a bit, but it was actually pretty close. The first step was to bust out the rotary tool and cut out the bottom. The bottom of the can had a nice rounded lip and then indented for the bottom surface. Once I cut out the bottom, I smoothed all the sharp edges with a circular grinding pad.
I then measured the height from the base of the turkey feathers to the ridge near the top and made sure that my inner cylinder would be about 1.5″ taller to give a nice look. Once it was cut down to size and sliced, I was able to temporarily insert it and see what it looked like with my mock-up speaker enclosure. I’ll end up creating some tabs on the inside of the turkey feathers so that I can attach this insert with a few screws.
As you can see it creates a really cool look inside the afterburner. I had to trim the mock-up structure back to its original size so that it would fit back down inside a smaller cylinder.
Then it was time to cut apart the mock-up structure and cut these pieces out of steel. It was pretty tricky to get the pieces of steel to sit the way I wanted to. So I ended up placing some tack welds on each triangle so that I could easily bend the angles into shape. Then it was a matter of tack welding all the edges together to hold them in place and then doing the finish welding to see how it would look inside the afterburner.
The final step for the day was creating a backing plate for the speaker enclosure to mount on that could also serve as a plate to hold the six “cups” that I wanted to add for decoration. The trick was to ensure that this backing plate would fit inside the diameter of the cylinder.
I also cut a circular hole in the center of this backing plate because I’ll need the room to place the speaker up into the structure. The idea is to build a speaker enclosure up inside the peak of the structure pointing back towards the car so that the sound can echo from inside the cylinder. Then I’ll create some little legs to raise the structure up off the backing plate to give a little bit more room for the sound to escape. To finish it off I’ll fabricate some bolt-on points to tie it all together.
You can see part of this circular opening in the picture below. But don’t worry, the opening isn’t way off center, it was just the angle of the camera mixed with the structure not being centered when I took the photo