Physics project help - trigger system

[lilsus]

Physics project help! - trigger system

I have built a rubber band powered helicopter for a physics project. It looks something like:
http://wings.avkids.com/Book/Wright/Images/WrightHeloVert_lg.jpg

Basically, you wind up the propeller, and the energy stored in the elastic bands, once released, will launch the helicopter straight up.
I'm required to have an attached trigger system to my model, and its purpose is for the helicopter to build up energy without me touching it at all. I have tried clipping paper clips, tying strings, wedging the paperclip etc etc, but nothing seems to work. It would be helpful if the trigger system is strong to withstand the force, but light so that it can go up with the helicopter. Also, the trigger needs to be released quick enough to get it out of the way of the helicopter.

Any suggestions?! Thanks in advance =)

 

[berkeman]

Drill a hole in the cork and insert a small tube of plastic with about a 2mm ID, angled up in an appropriate position. After you wind up the propeller, put a square toothpick (light and strong) into the tube, so that part of the toothpick sticks up through the disk of the propeller near its axis of rotation. Then just clip the propeller with dykes when it's time for liftoff.

 

[lilsus]

Berkeman, you are AMAZING! =) I'm not sure if the toothpick will withstand the force, but i'll try it now! I can't thank you enough!

 

[andrevdh]

A toothpick through the eyelet where the rubberband hooks on to the propeller will also prevent the rubber from unwinding.

 

[berkeman]

Good one! I missed that.

 

[thrasher1002]

hi, my name is Chris. I am in the 8th grade. if u don't mind, I am going to use this helicopter design for a project too. can u please tell me where i can get a propeller like that?

 

[berkeman]

hi, my name is Chris. I am in the 8th grade. if u don't mind, I am going to use this helicopter design for a project too. can u please tell me where i can get a propeller like that?

Welcome to the PF, Chris. This is a great place.

Go to your local "Hobby" store, and they will have inexpensive Rubber Band Airplane kits. Those kits will have much of what you need for your project, including the propeller and some balsa wood pieces that you may be able to re-use. Just look in your Yellow Pages phone book for Hobby Stores near you.

 

[darnell0520]

can I know what materials are needed to do the project...I really need it