Anybody with a bomber model eventually gets around to experimenting with dropping models of bombs from airplanes. These are usually solid foam pieces, or break-apart plastic shells filled with chalk.
I thought it would be interesting to experiment with models that actually carry some stored energy (in the form of a compression spring), to throw dust a bit more upward on impact (as opposed to just splashing outward along the ground). Below are links to files I posted on Thingiverse, and videos of tests dropping them by hand. These were designed in Fusion 360, and can be printed in any filament, and of course at any scale. I used ABS for increased durability versus PLA. A compression spring sits in the nose, and is released on impact, launching upward whatever is inside. I found that Indian Holi Powder disperses really well, and although it usually comes in bright neon colors, you can also find it (less commonly) in neutral colors like white, grey, and black.
If you want to try one out, and don’t have a 3D printer, contact me and I can give you one of these prototypes, as long as you promise to drop it from a plane and take a video. I have only dropped them by hand so far, and I wonder they behave when hitting the ground at much higher speeds. I also have some 3D printed mounts for the Eflite release that could be glued to any of these.
Here are two youtube videos showing tests:
Spring-loaded RC airplane bomb
Here is a link to the .stl files on Thingiverse:
