4
votes
1answer
200 views

How to build a car that stops at a certain distance?

I want to build a small car that is about 200 grams. I want it to run the following course and stop at exactly or about the the finish line. I can't use any controlling devices or electronics. I've ...
6
votes
2answers
698 views

How to Make a Lego Claw Arm?

I am trying to build a lego claw arm to pick up stuff that is out of my reach and I need some ideas on how to design it. I would like a mechanism to be able to open and close the claw from the ...
5
votes
4answers
322 views

How can I blow a stream of air for up to two minutes at a time?

I'd like to be able to blow a constant stream of air for up to two minutes. The purpose of this blowing element would be to play a harmonica, using holes punched in a roll of paper/film to expose ...
15
votes
1answer
2k views

How can I make a working pin tumbler lock?

I'd like to make a working pin tumbler lock out of LEGO bricks. I have already designed a key I'd like to use that should be compatible with five cylinder lock.