MAKE: Noise — Discuss this article

Showing messages 1 through 2 of 2.

• TWIK
  You must be logged in to reply.
  
  
  Hey,
  I've read the article and I'm a little disappointed about it. At my high school (in the Netherlands) the children who are in their first year (about 100 each year) make a little cart that rides against the wind, called a "TWIK" (tegen de wind in karretje; against the wind cart). First one of our teachers didn't believe it would work so he made a bet with some students... and he lost so he had to give them chocolate or something. But what my point is: it IS possible to make a cart like this, over 100 children a year make it at our school. Even better: everyone can order these TWIKS from www.opitec.com, a big postal order company in Europe, so I suppose there must be thousands of people making them. There is an instruction for making one at http://www.uk.opitec.com/cgi/ITANZBD%20%20%20%20%20%20%20142832023106?P_L=E&P_S=E&P_V=504376825-&P_PGM=&P_1=101773&P_2=H&P_3=&P_4=&P_5=&P_6=&P_M=
  I made one myself with a four-wheel drive using a elastic bend between the axles.
  Have a good time making your own "TWIK"
  Greatings from Holland,
  Daniël

  Posted by Daniël-Linschoten on November 27, 2007 at 05:51:10 Pacific Time

• TWIK
  You must be logged in to reply.
  
  
  Very interesting! But as my article said, the challenge was to make a cart that would begin by running with the wind behind it, and gradually reach the same speed as the wind, and then continue traveling into the wind (i.e. with a net headwind).
  
  If you increase the mechanical advantage of the propeller by using correctly sized pulleys, I have no doubt you can make your cart move into the wind. Even the one that I built moved a little into the wind when the belt was twisted appropriately.
  
  But to build a cart that starts with the wind blowing from behind it and continues to travel into the wind, you will have to change the direction the propeller turns the wheels (by reversing the belt) when the net wind direction changes.

  Posted by charlesplatt on November 27, 2007 at 09:47:26 Pacific Time