Completion finally feels like it is within reach. All the steel has been cut, excluding two saw cuts that will be fit a special way after the triangle comes together. My carbon process has been proven, though I intend to iterate it all the way until the end. The heat treating process for coloration is predictable. I think the jigs for attaching all the tubes are done. Small things always come up.
Currently, my carbon fiber tubing exceeds my expectations. While I have plans to make it even lighter, I would like to share the current Instron test results.
Under axial compression, the tubing withstands up to 8700 lbs. That’s fine with me. After yielding, it still withstands 8000. It does not spontaneously crack. Similarly under indentation, ultimate yield is 1720 lbs, however even post yield, it continues to hold 980 lbs. For whatever reason, my carbon does not fail in an explosion like everyone said it would. Maybe it’s because I followed manufacturer guidelines. Maybe I’m lucky.
As far as what hasn’t been done goes, I haven’t verified my carbon to steel adhesive. Because it is tubes inside tubes, my main interest is shear strength. The epoxy/polyamide compound I got is called “loctite e120hp hysol,” and is rated for 4000-4500 PSI. This means my weakest joint should still be 16000 pounds in tension at the weakest. Because full coverage of each joint is likely to be impossible, I’ve decided I’m willing to live with 6000 lbs. This test fixture nonetheless is currently curing and I’ll squish it on the Instron tomorrow.
The tubes have also not all been combined. I have a few pictures to show you all, both of setup and product.