Thursday, June 28, 2012

Will LEGO Technic helicopters ever fly?

Even just some years before this idea looked totally sci-fi, but recent advancements in mass producing of cheap, simple electric helicopters makes it actual. You can buy a simple beginner level coaxial electric helicopter model cheaper than a medium-sized LEGO technic helicopter set. Being both helicopter-/and LEGO Technic-addict, I started to think about necessary conditions and steps towards the goal above:

(Technical note: Sorry, this blog is not for absolute beginners. About working of helicopter rotors and controls see April 2011 archive of )

- Developement of aerodynamic, auto-folding main/tail rotor blades: technically, it is not a big issue , but children safety issues are serious, especially in USA, where anyone can sue anybody for anything for at least a million dollar.

- Developement of on board Li-polimer battery rechargeable from USB port of iPod, laptops, etc.

- Developement of smaller sized, brushless motors with adequate cooling (built in fan with vents)

- Developement of set of thinner, high tensile stenght, glass-fibre reinforced rods as shafts and structural airframe parts, with siutable sized ball joints and hinges. Child safety issues will occour.

- Introducing mini metal-plastic screws for vibration resistant and compact joints. Child safety issues will occour.

- Developement of specialized swashplate part with reasonable ball bearing

- Developement of more compact, vibration-secured electric plugs and cables with adjustable lenght connecting electric parts. Current standard LEGO Technic/Mindstorms plugs and cables are too big, too heavy, too rigid and vibration-unsecured, making them useless for helicopters and even for speedy robots.

- Adaptation of light servos in LEGO Technic environment. This is the costy part, but some coaxial rotor model helicopter designs do not need any servos.

- Developement of shock resistant piezo-gyroscope units: reasonable control of an RC model helicopoter requires 1-3 gyros (yaw trim at coaxial main rotor, pitch/roll/yaw trim at single main rotor). Current cheap gyros „go mad” after some hard crashes, which naturally occour frequently. Re-calibration of gyros with suitable software after crash may help.

 - Developement of a flight computer, which communicates over wi-fi with flight control software on iPod or laptop. This way the costy, clumsy, battery-eating conventional RC-controller can be spared, and there is a possibility for two-way communication, transimitting on-board camera picture stream also. Ideally, flight computer should be programmable from PC/Mac GUI software.

- Mechanics of simple 4 channel electric coaxial helis (2 brushless motors, 2 servos, 2 gears, 2 rotors, flybar, 2 gyroscopes, Li-Po battery pack, flight computer) could be wrapped into a strong "flying core" component, and conventional LEGO Technic stiff/flexi rod structures could be built around that

- Using transparent/colored decals, not as decoration, but lightweight stressed skin cover of aerodynamic surfaces (blades, stabilizators) and on airframe to save weight.

In the following posts, I will show, how I experimented with all these above.

First I started out rebuilding current LEGO Technic sets, and then designing my own.

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