Skip to main content

390mg Plane - My Lighest Plane & Unoffical Record Holder

To date, this is the lightest plane I've ever built. It held the unofficial record of the world's lightest plane for about 4 months back in July of '08 until it was bested by one weighing 225mg. To date, I don't believe any lighter ones have been made.


This plane is my crown jewel of micro plane accomplishments... Despite the mountain of headaches it took to build. It has a 3.1" wing span, a 1" chord, and is 3.5" long. Flight times were surprisingly high, around 4-5 minutes, considering the size of the motor. An infrared transmitter/receiver system was used to control the throttle and rudder. The rudder control is done though an electromagnetic actuator.

The frame is made of carbon fiber rods ranging in size from 0.01" (0.25mm) to 0.005" in diameter. All the rods less than 0.01" diameter were hand sanded down to size. The covering on all the surfaces is OS film (DuPont).

All the electronics in the IR receiver - microprocessor, FET, and IR detector - were sanded down to reduce weight. The aluminum that encases the 8.5mAh lithium polymer battery was trimmed away to get the battery weight lower. Even then, the battery weight was 75% of the plane's weight.

The motor and propeller were custom designed & built to power this plane. The motor is a single phase brushless design swinging a 0.6" prop. A video of it can he seen here.

Weight Breakdown:
Airframe + Act: 37mg
8.5mAh Li-Po + On/Off Switch: 290mg
IR RX: 25mg
BL Motor: 30mg
Prop: 5mg
Landing skids: 3mg

All up Weight: 390mg




Original Post: 390mg Plane on RcGroups




Comments

Other People Thought These Were Cool..

Micro Servos

When I started to take a break from microscopic flying vehicles in 2010 and migrate towards some larger, easier to work with, models (5-20g) I realized that magnetic actuators just weren't going to cut it for control (rudder, elevator, ailerons). Magnetic actuators are heavy and draw power continuously when deflected away from neutral. I needed servos. Servos would provide lots of pulling force for their weight but at the cost of mechanical complexity. Since servos at the weight I needed didn't exist or were out of my price range I decided to further over complicate the situation and build my own. I started by designing a simple linear servo (lead screw design). The picture above is of my 400mg variant which has a throw of about 0.2", resolution of 0.0015", and can pull about a 25g load. The motor is a brushed 3.2mm diameter coreless design by Shicoh. The gears used are module 0.15 and can be gotten from http://www.kkpmo.com/ . The threaded rod is 0000-160, which...

3D Printed Mechanical Pencil

What better way is there to spend multiple consecutive weekends than sitting at your computer, redesigning a mechanism that has existed for decades, all to be able to 3D print something that can be bought at the store for less than $1? ... That's right, anything. However, when your co-worker throws down the gauntlet there is only one thing to do. Take it up.

840mg Biplane

I built this back in May of '07. With this plane I wanted to focus primarily on small size. I was still going for something lighter than my previous plane but I wanted to make an airplane that even I thought was small - a tall order considering I had been building micro r/c planes for year or two at this point. I chose a biplane design for this plane because it would allow me to keep a high wing area but keep the wing span small. The wing span on this plane is 2.75", the chord is 7/8", and the length is 3.75". The frame is all made of balsa wood and covered with OS film. Flight times were in the 4-5 minute range per charge. It is powered by a 3.2mm diameter brushed motor and a 1" propeller. The infrared receiver is capable of controlling the throttle and the rudder with a 7 step proportional control. The rudder is driven with a small electromagnetic actuator. The power source was a single cell 10mAh lithium polymer battery which can be recharged. Weight...