Summary

These legs were designed to allow a quadcopter to be portable by making them detachable. After printed, there are two main components; the base which is a short profiled female clip, and the leg which clips into the base. The short base alone can serve as small legs to give a quad (or whatever you like to place it on) a nice and even support on the ground. When you need more clearance, attach the legs into the base.

Instructions

All parts were printed in PLA except for the female clip (the base). That was done in ABS. But I suspect you can print that in PLA.

1) Legs (both left and right)

Just make sure your platform is clean. This part has a lot of contact with the plate. No support is needed for the overhangs.
0.8 mm walls
20% infill
0.8 mm top-bottom

2) Leg to clip adapter

The side with the pegs is the top. Use support for the bottom.
0.8 mm walls
20% infill
0.8 mm top-bottom
30% support infill
support brim optional (I printed both with and without)

3) Male Clip

This may take some practice but it is doable. DO NOT print this with the clip facing upwards to avoid supports. If you do this the clip will shatter because you will be bending the ends which will peel the layers apart. Print flat with the clips parallel to the print bed so that the flex will be along the layers. The walls need to be thicker to withstand the flex.
1.2 mm walls
30% infill
1.2 mm top-bottom
30% support infill everywhere
support brim required (20-30 rounds)

4) Base (female-clip)

In terms of printing, the clip insert is the top. And the flat, solid end is the bottom. Support is optional.
0.6 - 0.8 mm walls
10-15% infill
0.8 mm top-bottom
support is optional (I used none)

Assembling

These parts are meant to fit snug together. Better tight than loose (I am not allowing anyone to claim a "that's what she said". I already claimed it). It's fairly simple to refine it later after you printed. I used standard super glue for assembling the legs, and 10 lb 3M tape for the base.

1) First, test fit the adapter plate and male clip. The pegs go into the holes of the clip. The holes in the clip may be too small. In that case, use a drill to widen it just a little. Connect and glue the male clip to the adapter plate and let dry for about 30 minutes.

2) Before attaching the leg to the adapter plate, I found it best to break in the clip. It's very possible that one of the clips may be weak and shatter. You don't want to glue the leg and find out that the clip is defective. At this point the adapter plate should be glued to the clip. Go ahead and snap the clip into a base. Let it sit for a couple of minutes to allow the clips to flex. Then take the clip out of the base. First time is always the toughest. I don't pull the clip out directly. Push on the edges of the plate to 'wiggle' the clip out. Do this several more times. It'll get easier. (Please, no TWSS)

3) Test fit the other end of the adapter plate to the leg. Then, glue it on.

4) Repeat 3 more times.

Detachable Quadcopter legs