Carbon fiber is one of those materials that can transform the way we do things – it's light and super strong. For the DIY builder designing a plane to take the inevitable "close encounter of the ground kind", carbon fiber tubes can make excellent building blocks for frames and wings. To try out this out, I started to build a "demo plane" using carbon fiber tubing.
After ruminating a bit about how to ensure a light but structurally sound frame, I started with the firewall. I made a jig to keep the firewall perpendicular to the bottom two tubes and attached four tubes to the firewall:
As the tubes are at the outermost edge of the firewall, a good smack might dislodge them. I decided to bind the tubes to the firewall using a combination of fiberglass tape around its perimeter, then tying the tubes together with piano wire inserted into the tubes about one inch.
I used the same technique for the rear – epoxy and tying the tubes together with piano wire:
The landing gear is bound to the bottom of the firewall, completing a basic frame:
This weighed in at about four ounces – depending on what's used for skin, the basic frame could weigh in at about 6 ounces with something like Sig Koverall, and on up if balsa is used. The landing gear is the shock absorber that I wrote about earlier:
The bottom piece is 1/16" plywood for strength.
Wing construction is another natural to use carbon fiber tubes as wing spars:
This wing is composed of 1/16" plywood ribs with three carbon fiber tubes used as spars. I shaped the ribs by bolting them together and using a stationary belt sander to shape all of them at once – this ensured that they were identical. I then drilled out holes (while still bolted together) for the spars, which were epoxied in place.
The resulting wing was 36" long, too short for the model I finally decided to build, so I'm going to build a 48" version with an 8½" chord. The wing with just the ribs and tubes weighed in at about 4 ounces – once again the covering will determine the final weight.
CONCLUSIONS
Building a plane to take some knocks does not mean it has to be built like a tank – carbon fiber tubes offer light and strong building blocks for modelers who want to roll their own.
NOTE: This is a new site so please consider it a "work in progress". I would greatly encourage readers to send in articles for posting on AmpAviators. In contrast to a forum, finding articles of interest will be TONS easier here.
Carbon Fiber Tube “Building Blocks”
Rugged DIY building
Carbon fiber is one of those materials that can transform the way we do things – it's light and super strong. For the DIY builder designing a plane to take the inevitable "close encounter of the ground kind", carbon fiber tubes can make excellent building blocks for frames and wings. To try out this out, I started to build a "demo plane" using carbon fiber tubing.
After ruminating a bit about how to ensure a light but structurally sound frame, I started with the firewall. I made a jig to keep the firewall perpendicular to the bottom two tubes and attached four tubes to the firewall:
As the tubes are at the outermost edge of the firewall, a good smack might dislodge them. I decided to bind the tubes to the firewall using a combination of fiberglass tape around its perimeter, then tying the tubes together with piano wire inserted into the tubes about one inch.
I used the same technique for the rear – epoxy and tying the tubes together with piano wire:
The landing gear is bound to the bottom of the firewall, completing a basic frame:
This weighed in at about four ounces – depending on what's used for skin, the basic frame could weigh in at about 6 ounces with something like Sig Koverall, and on up if balsa is used. The landing gear is the shock absorber that I wrote about earlier:
The bottom piece is 1/16" plywood for strength.
Wing construction is another natural to use carbon fiber tubes as wing spars:
This wing is composed of 1/16" plywood ribs with three carbon fiber tubes used as spars. I shaped the ribs by bolting them together and using a stationary belt sander to shape all of them at once – this ensured that they were identical. I then drilled out holes (while still bolted together) for the spars, which were epoxied in place.
The resulting wing was 36" long, too short for the model I finally decided to build, so I'm going to build a 48" version with an 8½" chord. The wing with just the ribs and tubes weighed in at about 4 ounces – once again the covering will determine the final weight.
Building a plane to take some knocks does not mean it has to be built like a tank – carbon fiber tubes offer light and strong building blocks for modelers who want to roll their own.
NOTE: This is a new site so please consider it a "work in progress". I would greatly encourage readers to send in articles for posting on AmpAviators. In contrast to a forum, finding articles of interest will be TONS easier here.
Email Joe