Backplate-to-legs hinges?

I can’t seem to figure out the leg hinges with the holes in them. The only position they seem to allow a cotter pin to get inserted creates an almost straight connection between legs and the backplate (see the picture).


While this seems to work nicely while it is sitting there without cage, batteries and harness, it appears too sensitive to tip backwards already. I can only imagine how this will get even worse when the batteries are mounted.
So is this what everyone else did? Or is there a way to tilt the backplate forward a bit to move the CG more to the center of the legs?

The hoop should determine the position of the back in relationship to the legs. On my unit I put SS cotter pins in the top hole of the three (one on each hinge). Once I install batteries, the cg does shift back, but I am just careful. Here is a link to my build…don’t know if it will help, but you will be able to see the hinges and the pin(s).

GliderPilot designed and 3D printed hinge stops that serve the same purpose as the pins.

The hoop mounts look like up with the ends of the arms it should be right. Yes it is a little tippy with the batteries mounted. The harness helps. With for Bonkas the cg will be above the middle of the legs pretty well.

I don’t fold my legs for transport. I’m careful where I set it down on the turf with the arms folded in. When I unfold the arms it tips forward. When I mount the batteries it tips back. Attention to the ground under the legs is required for setup and breakdown. Last time I was out I let it fall forward onto the swing arms and harness when I removed the batteries. :flushed: No harm done except to my pilot ego.

I had this problem… My lower hoops had an awkward angle. Since I use 23inch props I realized the lower
two arms were closer together than the upper two arms! I figured out that the center hoop was to
close and I spaced it out, so all 4 arms have the same distance to each other. Now the angle from the hoop is perfect but I had to put door stoppers on the ends of the frame. It had a tipping to the sides tendency… Now it sits securely even with the batteries on the ground.


The 3d printed plastic parts that fit into the end of the legs to mount the hoops determine that angle. They have a slight angle themselves. Is one or both of them installed incorrectly?