Another model rocket launchpad but with different offset flat folding hinge design.
Hinge incorporates stops to space legs evenly when open.

Designed for M4 hex head bolts and nuts (qty 2) and I fitted (hot press fitted) an M4 x 8mm threaded insert to the rod mount for strength.
Launch rod 3mm or 1/8".

I designed legs with their own in built support locally at the hinge features where required. This should be simply trimmed off and smoothed after printing.
Alternatively I could post versions without the additional support features if desired.
I suggest at least the hinge area of the legs should be printed 100% infill or with a good number of perimeters to ensure the high stressed hinge area is strong enough.
I used a modifier to print the hinge area 100% infill and 3 perimeters while printing the rest of the leg at 15% infill 3 perimeters. I'm hoping this gives a good compromise on strength/weight/print time and plastic used. Time will tell how strong this turns out being.
Legs I printed in Prusa ABS-T mainly because I had a reel I wanted to use up in a good colour. Next time I think I'd be happier with PETG.

Rod mount components I printed in PETG from Rigid Ink and I am pretty happy with how strong they appear. They require some support.
Holes will likely need a drill run through them to fit rod and screws well.

Hope this proves useful to someone else.