Sunday 24 March 2013

Marble Machine #2

Back in January I wrote about the fun I’d had putting together my Marble Machine #1 from Busted Bricks ... and then during the course of February Michael dropped by the blog and posted a rather teasing link to a new design called, wait for it! Marble Machine #2Having had a quick squizz at the YouTube video, I’d pretty much decided that I wanted one so I began dropping by at the Busted Bricks web site on a pretty regular basis (I know, I know!), until eventually a couple of weeks ago MM#2 went up for sale – and I immediately ordered my copy. 

It arrived about a week later and the first thing that struck me was the size of it – this one’s a lot bigger than MM#1! I suppose I should have realised that from the video, but I’m not the quickest...

As with the previous machine, the assembly instructions are available as PDF files on the Busted Bricks web site making it pretty handy for either printing them out or indeed having them up on the PC while you’re building it, as I did ... and it means that Michael can update them instantaneously if anyone suggests any improvements. 

The kit is wonderfully complete containing literally everything that you’ll need to complete the build bar some glue and a pair of AA batteries to power the motor. The little bits and pieces (that’s technical jargon for nuts and bolts, pieces of silicon tubing, carbon fibre rods etc.) are all safely secured in sealed plastic bags so you can’t lose anything... and Michael’s pretty much thought of everything, right down to throwing in a small bit of sandpaper and a 15cm ruler for measuring out the lengths of carbon rod. 

MM#2 has a single large lifting wheel at the rear of the structure that lifts balls from a collector tray on the base up to a flip/flop switch at the top which sends alternate balls down two different sets of tracks. 

The track on the left is made up of a series of tilted slopes with the balls dropping onto the next alternating slope at the end of each track. 

The right hand track has a run more akin to MM#1, except that there’s a little trick halfway down in the form of an accumulator that collects the balls until there are three and then releases them all together down the last section of the track... the lifting wheel is driven by a tiny motor running on a pair of AA batteries neatly tucked inside the base.

Assembly starts with the base that is built up of some interlocking pieces that go together rather easily... while that dries (assuming you’re not using CA) you can move onto one of the next sub-assemblies, until that needs to dry and so on – this one has quite a few little discrete bits of work so you can easily find something else to work on while one of your pieces of work is clamped together waiting to dry. 

Michael’s already done most of the hard work on the lifting wheel which arrives with the holes pre-drilled to the right depth and angle to ensure that the balls not only fall into the holes at the bottom, but roll out when they reach the top of the lift... there’s a little bit of chamfering to do around the edges to help the process, but that’s about all. 

The flip/flop switch mechanism needs a bit of care to make sure that it is going to flip and flop at the right times – but the design has been pretty well thought out, so it’s hard to mess it up ... and the same is true of the accumulator that relies on a small counter balance to collect the first two balls and then release them all when the third ball arrives in the accumulator tray – I had visions of having to fine tune the counter balance and finesse the hinge mechanism to get it all working properly however it all just worked perfectly, first time – serious credit to the design. 

Assembling the lengths of track is also pretty straight-forward as the only two sets of joins have been shaped differently so you couldn’t possibly get them the wrong way round if your tried... final assembly of the tracks on their carbon rod supports is a bit fiddly but once you get them started, they pretty much take up their final shape on their own. I found myself fiddling with the spacing a wee bit to get things more or less evenly spaced before I turned it on for the first time and then sat back and watched my handiwork – and it’s terrific! The balls flick left and right alternatively and the accumulator on the right hand track works perfectly ... it’s a great little piece of kinetic sculpture ... thoroughly useless, totally endearing!

Michael’s done an excellent job on the design and on putting these kits together. 
Everything you’ll need is included, down to some extra carbon rod to use as alignment pegs when you’re gluing bits of the base together and a sighting rod to use when you’re lining up the wheel supports. 

There’s a lot more building involved in this model than in the previous one and I probably spent about 6 hours on and off over the course of a weekend putting it all together – I’m not the world’s speediest builder, but then I enjoy the process as well as the outcome... and I really enjoyed putting this one together... and even Gill thinks it’s cool!

Oh, and if you really want one but the idea of having to build it yourself puts you off, have a look at the Busted Bricks web site because Michael has started offering pre-built Marble Machines as well...


  1. I knew you'd get one of these!! Looks great. I must admit I'm tempted.

  2. I still need to go build the first one, which I'm looking forward to doing ... just as soon as I finish the other projects I have! Thanks for the look at the next one Allard. It does look great!