DIY Carbon fiber hoops


#1

I’ve been exploring the possibility of making carbon fiber hoop sections. I’m not a PPG-er (yet) so I’m putting my tests here in the hopes of feedback from the community about whether this is a good idea. I’m also open to suggestions for changes.

Here is a picture of the finished test piece:

Here is a movie explaining the results:

In a separate post I’ll list the steps. Here are pictures of the connecting pieces, which I’ll print on a Form2. The red sections are screw pins from here:


#2

Here are the pictures explaining the process:


Carbon fiber sleeves (we will use two layers)


1/2" insulation foam from hardware store. Look for sections that don’t have dents.



Slide the sleeve over the foam, pull tight, and secure with zipties. This is still dry. The fibers should be at 90° angle when expanded over the foam.


I use MGS epoxy because I have some left over from my airplanes, but West systems would work fine as well.


Wet out the sections with epoxy resin. Try to get rid of as much extra as possible. Just use enough to give rigidity to the first layer.




Let the epoxy cure just so that it is fairly stiff and will withstand the heatshrink compression. Cut off zipties. Trim off the extra fibers and protect with tape.


Note the flat section. I used too much resin on this sample and it pooled on the waxed paper. Use less, and flip over a few times during curing.


Slide the second layer of sleeving over the first.


Secure second layer with zipties.


We will use special heatshrink from sollercomposites:
https://www.solarcomposites.com/composites/carbon%20fiber%20sleeves.html#Shrink


Wet out the second layer. You can have as much resin as you like, and you should saturate the fibers.


Slide the heatshrink over the set of sleeves, and start at one end with your heatgun. Use just enough heat to shrink the heatshrink and force the extra resin out the cool end. Go slow and let the resin soak in as you go.


Let cure for 36 hours.


When cured, run a boxcutter or xacto knife along the heatshrink to cut it.


Peel off the heatshrink.

I finished these by using 1500 grit wetsand, and then 3 coats of UV-resistant clear coat.


#3

Super dope, I like it. Ya CF tube for the outside ring would save some weight. I’m really interested to see where you take this.


#4

Here is a better movie explaining the finish coat and my plans for the connectors:


#5

Here are some updates in pictures and a video.