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No balsa, no problem.

Alternative firewall materials

This weekend was a bit interesting.

Friday night I pulled out my HK Tuff Trainer for the first time. It moved with me from Ohio and the movers did a number on it, but nothing a but of hot glue couldn't fix.

Or so I thought.

Turns out the fuselage was warped internally in a bad way, which caused the tail servo to overheat and burn out just trying to move the tail. It also caused it to stick around 1/8th of an inch in any direction. Not good!

So I started nosing around for a better trainer to start with then I noticed Flite Test promoting their swappable kits. Cue many hours of watching videos.

Now it's Sunday, I've hit up the local Dollar Tree for some foam, salvaged some parts from the TT, and had the pod all built up except for the balsa. I was going to just pull the firewall out of the TT but it's too small. I didn't want to drive out and buy a sheet of balsa just for this (nor do I know where I'd source any locally), so this meant it was time to return to the swappable spirit and find something else.

With that in mind, I present to you the CD firewall.


The firewall design just barely fits inside the outside of a standard CD, so grab your dremel, a drill, and a vise. I skipped the routing hole for this since I wasn't sure how strong it would be (and I've not flown it yet so it's entirely possible this could go horribly wrong) but the plastic feels very durable. All of the holes drilled without cracking the plastic, and the motor feels very secure. The screws bit in well and don't feel loose either.

One thing to keep in mind when drilling is that the top side of the CD has the data and label on it. THIS MUST BE REMOVED OR PLACED ON THE OUTSIDE OF THE FIREWALL. If you attempt to glue to the label, you will have a bad time.

You may also want to cut off the drill tails, I didn't here because I thought they might help alignment of the skewers, but I've not built a fuselage yet to try it out. For reference, I used Memorex CD-Rs which I've had for a while. Different brands may have different properties. The Memorex ones seem to be very strong at firewall size and weren't prone to cracking or separating. The hot glue also seems to adhere to it very well once I removed the label.
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