Goat has been ready to fly for roughly three years, but the maiden flight has been delayed behind my inability to transport it to a place to fly. The closest place I'm pretty sure I can fly is about 2 hours away at highway speeds...
The aluminum trailer I built a couple years ago was too flimsy, especially in torsion. In hindsight, going with thin-walled steel would have been easier for both welding and stiffness. That said, learning how to TIG weld has been useful, and having a reasonably lightweight trailer will be better for using a diminutive Prius as the tow vehicle. The answer (hopefully) is adding a railing to provide more structure.
Trying to balance low weight and strength, I went with 1.5in x 1.5in x 1/8in 6061-T6 angle for the railing and risers. The cross-braces are 1.5in x 1/8in bar stock. Each riser is spaced 3ft 4in apart and is 28in tall from the bed. If the top of the railing is not stiff enough, I may weld on a 1/4in bar across the top.
I'll eventually add walls and a lid to this frame. If the current height is insufficient for packing the wings and tail, the lid can have some depth to it that adds height. A closed lid will also add significant torsional rigidity, so that's in my back pocket.
Using angle for building the railing system is a copy/paste from other commercially-available trailers I've seen. The joints are surprisingly accessible for welding, which is a lot easier than had I gone with square tube.
I'm still quite a novice at welding, and adding this railing after the deck is done has means every weld is done vertically (and a few inverted). Several welds are combining thick and thin material, which is also a challenge to weld without melting away the thinner material. Let's just say I'm only proud of about every fifth weld. This has been a wonderful learning project.
For decking, I have three pieces of 4ft x 8ft x 3/4in furniture grade maple faced plywood that have been sitting in my basement literally for 13 years. These are overkill, but are effectively free at this point. My real plan is to get composite panels (fiberglass face sheets on plastic honeycomb cores) that are 1/3rd the weight for the same price. I can also fillet the corners with epoxy and bias glass to make the box watertight
All the new material is now spent. I have a small follow-up order to do, though it will not include any more 20ft pieces (thanks again Sam for the help with transportation!!).
One step closer.
