Helicopter recovery with lego

[mooffle]

Hi everyone, I'm new to the forums but am a long time builder and flyer so I figured its time to start sharing some of my design and maybe get some feedback. Bear with me as I get used to posting.
I've always wanted to build my own heli rocket but had no idea where to start with regards to blades and hubs. After looking at some off the shelf hardware I came up with this lego/rocket combo.

First flight was this weekend on a B4-2, went up around 200ft and the blades opened surprisingly cleanly.



Some quick build details
Those lego pulley wheels and the associated white rubber bands are the EXACT same diameter as a BT-50 and make for a near perfect friction fit.
The small plywood pieces on the blades make them completely field hot-swappable.
I know its kind of ugly but those yellow alignment sticks keep the rocket stable, if the fins don't hold down the blades at the right angle there isn't enough fin area to keep it flying safe.
The fins also originally weren't big enough hence the big 'fin/winglets'.
A longer shock cord would be nice as I think I made it way too short.

 

[BABAR]

Very cool!

Something you can try for easier build and better performance. The hockey stick ends of the rotors will function as FINS during boost. Look up fliskits tiddlywink. So you can make those bigger, go with NO fins on the rest of the rocket. The larger "rotor-fins" provide more surface area for the descent phase. So it is win-win.

 

[mooffle]

Thanks, I'll definitely keep that kit in mind if I do another with this hub design, or when it inevitably breaks on impact due to being heavy and i'm forced to redesign it.

 

[Crawf56]

Go do
that voodoo
that you do
so well!

 

[mooffle]

Quick update after some (mostly) successful launching.
I finally got around to naming it Back Flip and painting it.
The lego hinge pins had to be swapped out as the ones I used were far too short and loosed up on one of the flights, thankfully 2 blades opened enough to slow it where no damage occurred. Of all the things I overlooked when building it is the shock cord is waaaaayyyyy to short and the tube now shows it.

 

[BBowmaster]

One of my students is both a rocket and LEGO enthusiast. He’s going to love this.

 

[Aeronerd]

Very clever project and use of legos.