What If? machine

The Derby Makers What If? machine at the Silk Mill

Several weeks ago, Derby Makers were asked if we wanted to take part in a What If? machine display to be held at the Silk Mill as part of Derby Feste.  As we're still very much a new group and we're still find our way, we thought about it for a while, and eventually decided what the hell, why not?

The question was 'What is a What If? machine'?

It turns out, we would be designing a segment of a Rube Goldberg or Heath Robinson machine based (very loosely) around the theme of 'games'.

All the had to go on was the design of the trigger mechanism (a lovely piece of rubberband engineering) and the size of each segment (around 2 square meters).

Everything else was up to us...



As often happens with these sorts of thing, someone happened to glance at a calendar and realized that the event was only a month away - time to panic!

We devoted time at one of our Tuesday evening meetings to a brain storming session and came up with some brilliant ideas for what to build - next week was the time to queue the music, raid the workshop and get stuck in. At the next meeting, we started off building our frame - a roughly 8' x 4' base we could attach things to.  Water power had been suggested by most people, so a back support to but the water on was loving hand crafted by skilled artisans - this wasn't just bolted together any old how!

What If? Machine framework

For the water support, we decided to channel our inner Heath Robinsons and a cantilevered support shelf appeared on the top.  It was probably around this point (the first couple of hours of building the thing) when it became apparent that all the ideas we'd thought of would probably not make it into machine given the lack of time.  We'd settle for anything that might work...

Firing a cricket ball at a target seemed like a good idea, and soon a surprising reliable bungee powered ball launcher took shape.  The target it hit would trigger the next machine - Half way there!

Throwing arm, first attempt

How to trigger the ball was another issue.  And soon a water wheel powered candle based trigger mechanism was dreamed up and started to take place.The input trigger evolved into a carefully balanced bottle of water that would be tipped by the input trigger.  Nearly there...

And eventually the overall design of the machine took place.


The input trigger would knock over the water bottle.  This would empty water down a vuvuzela end direct it unto a small water wheel.  The wheel would (hopefully) turn, pulling a small cart with a lit candle on top.  When it reached the endstop, this would burn through the trigger string holding down the throwing arm.  This would fire a cricket ball at the end wicket, which would set off the next machine.  Easy!

Well, Saturday morning dawned bright and early with a few tinkering tasks to finish off. After a couple of successful test firings, we were looking at how we could improve things.  We had originally wanted an umbrella to open as part of the machine, but had left it off due to time constraints.  Dominic from Nottinghack threw down the challenge that there was plenty of time left and we should try to add it in.


Challenge accepted!  And 30 minutes later, we had the beginnings of a umbrella trigger using the cricket ball throwing arm - Bodgetastic!



Each machine in the room was individually tested to make sure they would perform as required, and then came the nerve racking procedure of connecting each machine together.  This involved many meters of string, fishing line and bulldog clips.  Soon, each machine stopped being an individual machine and were all components in the larger system.

1pm soon came around, and it was time for the first full firing of the What If? Machine, and apart from a few minor niggles, it worked! Each over the top, Heath Robinson device operated and triggered next one in the sequence.

The rest of the day was spent reloading the machine and gently tweaking the trigger mechanism as we had experienced a few glitches, but overall it performed brilliantly, much, much, much better than it should have done given the length of time it took to build.  All of the machine did fantastically well and all of the participants should be extremely proud of their work.


 Thanks to everyone who took part in, or came along to support today's fun in the Silk Mill.

And special thanks must go the organisers for allowing such a great event to take place :-D


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