Hacking Neil Downie – Day 4

Editor’s Note: Hacking Neil Downie is a week of experiments with the ideas and designs from Neil Downie’s brilliant and playful books on Saturday Science. When the kids in the group discovered that Neil is a real person who lives and works in England (and sometimes in Pennsylvania), they wondered why they couldn’t ask him their questions directly. In this blog, they will.

All week we will forward him their thoughts and questions.

Dear Neil Downie,

Finally, a picture of the tornado transistor.

Linnea's transistor


Nick's Transistor

Is it cheating that I simplified it for my group?    Angus

Dear Neil Downie,

Doing the Wave! The Rotorope is beautiful.

Without the flash

Yale lent us a stroboscope. Cool to cooler.

With the flash

Can you show us how to build a stroboscope too?      Anna


Dear Neil Downie,

I figure it took my group and me 5 hours to work out the Slimemobile. It was worth it. And fun all the way. Am I slow? Should it take that long? I’m glad you rated it more than a little difficult.   Monika


Dear Neil Downie,

Here’s my confession. My dad is an engineer. He helped make the Segway work. I have been working on Gravity Reversal. He says easy: just an inverted pendulum. First day, I got it: a 6mm dowel, 30 cm long, swung right up. Then everybody said try this or that.  nothing but trouble.  I have gone back to my basics. But I  am unsure how  to make it  easy  for little kids. What am I missing?         Annika




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2 responses to “Hacking Neil Downie – Day 4

  1. Neil A. Downie

    Dear Annika, Monika, Anna& Angus, What about a Leonardo Bridge ? Its all made from 2″ square timber with notches: I will send a pic. Have a great day today. Neil

  2. Neil A. Downie

    Dear Angus, your tornado transistors look great. Maybe a clearer kind of cup would help see what is going on ? The LED is a nice touch, so you don’t need as much current to make it go. Neil
    Dear Anna, the Rotarope is really interesting, isn’t it. Have you tried a piece of elastic band for the ‘rope’ ? You can just use a rotating disk with slots cut in it, which you rotate in front of your eyes to view. You can make a simple flashing stroboscope for use in a dimly lit room out of a bunch of ultra bright LEDs – then you don’t need high voltages. You can use an oscillator circuit like a 555 (rapidonline.com)or multivibrator, then add a power transistor to the output – but make sure that you put in a resistor to protect the LEDs from too much current. Velleman do a kit, get it from American Science & Surplus
    Best, Neil
    I think that the Slimemobile is pretty difficult – and messy !! So 5 hours is good. Neil
    Dear Annika, I guess the easiest way to get the gravity reversal is to use a jig-saw! But for little kids, the vibrating ruler is more practical. YOu can ‘tune’ the ruler vibration by changing the motor power and then changing the length of ruler over the edge of the table. Best, Neil