Cool Engineering

Info on some cool engineering projects

Thursday, November 02, 2006

A $3 helicopter landing gear

Having recently acquired a model helicopter – I have learnt that the first important skill to master is hovering. Generally the way this is done is by attaching a trainer landing gear to the base of the plan – this stops you cutting up your props when you pitch or roll the chopper too much. Unfortunately the model I purchased didn’t come with a training landing gear – so I decided to make my own – with a total cost of around $3 (compared to the >$15 models for sale it stacks up quite well).

Equipment required:

- 4 ping-pong balls (purchased a pack of 6 for $2.99 – Rebel Sport)

- 2 metal coat hangers

- 1 drill, 1mm drill bit

- 4 small cable ties

- Heavy duty pliers

- Electrical tape


1) Straighten out the coat-hangers and cut to size (for me 70cm suits quite well)

2) Drill a hole straight through each ping-pong ball so it comes out the other side

3) Thread 2 ping-pong balls onto each strip of wire,

4) Bend up the last 5mm at the ends of the wire to an angle of 90 degrees

5) Move the ping-pong balls to the ends of the wire and put ome electrical tape over the bent wire to hold it in place and prevent scratching

6) Cross the wires over and attach to chopper with cable ties.

7) Put a small amount of electrical tape into the centre of the crossover to keep them centred with respect to each other.

Wednesday, November 01, 2006

Chopper Flight 1

It would seem that helicopters are slightly more difficult to fly than their fixed wing cousins. Basically I have flown the helicopter for all of 5 seconds. It began to bank slightly (about 1m off the ground). I reduced the throttle (a habit from fixed wing aircraft). The chopper hit the ground with a thud. In the movies when helicopters crash (which is about every movie with a helicopter) parts go flying off everywhere - well the same is true for model helicopters - myth confirmed!
I managed to find the tail rotor 5m in one direction and the vertical stabaliser 5m in the opposite direction. Currently I'm missing the tail rotor drive gear. I also need to work out how to balance the props properly - as at the moment they are unbalanced and I'm unable to achieve lift-off.