It was an article on Jelle's marble races on the BBC web site that led to several hours looking at YouTube videos of some marvelous creations by Jelle and others of marble runs. I thought I'd love to have a go at that, then went through the negatives:
Limited time
Limited space
Limited tools
Limited engineering skills
Inquisitive cats who will wreck anything
Not wanting to give up I decided that the best solution was to keep it small and keep it contained in a box... A box does limit the size of the run, but scaling down the balls helps. I found a source of 8mm marbles (probably Czech glass designed for crafts rather than games) ordered those and also picked up some steel and brass ball-bearings. I found some reasonably priced birch ply boxes on Amazon and decided to go ahead...
The box:
I gave the box (smaller than visualized...) a quick coat of stain and thought about design.
My engineering and woodworking skills aren't the greatest, but I used to make models as a kid and decided that maintaining an aesthetic would be the best option for a small space.
With a bit of spare copper pipe and a few fittings left over from a boiler replacement I decided an industrial feel would work - hopefully the finished project will have a slight 'steampunk'/'mad scientist' feel.
Two holes drilled (one for the inlet pipe and one for the outlet), I'll use the lid to store a removable release gate and capture/finish line piece (having a hinged bridge and using the lid as part of the run was an initial idea).
The interior has been painted black to increase the illusion of depth and set off the metalwork. The outlet pipe and inlet pipe have now been roughly positioned.
To be continued...