I finally have a donor bike to build a trailer with. I was thinking a single wheel design using the front fork and wheel as the wheel.

I've seen a couple of good ideas online, but I'm struggling with finding a good hitch design.

I'm thinking something that mounts on the rear triangle and not the axle (problematic with my rack to some extent.

Anyone have any DIY designs for this that they're happy with? I was looking on instructables and they always seem to buy a hitch or mount on the seat post. The other designs I find seem complicated.

I don't weld, so that's a limitation.