OMG this is the project that just won't die...

I had the machine out again the other day and tried to use it to actually sort some Lego for once (rather than as a cute demo for some school kids). It still has niggly problems that I want to fix:

• the colour sensor is currently 'open air' - there's no window - so all kinds of fluff and dust, not to mention actual Lego, gets stuck in it.
• pieces, of all sizes, still come through in two's and three's all too often, degrading the sorting accuracy somewhat
• the very smallest pieces often don't slide all the way past the colour sensor; the gradient of that part of the Vee channel isn't steep enough and with so little momentum they stop until a bigger piece hits them from behind and nudges them along.

So, I've been thinking. Add a window over the colour sensor, and deal with whatever fallout comes from that. Shorten and steepen the final stage chute so that small pieces don't get stuck. And in the middle, maybe add a second vibratory feeder - with a twist. More on that in the next logs.

To date, I've modified the sensor to add a window made from a thin, curved piece of clear acrylic. It seems to be very good at keeping debris and Lego out of the sensor, but it's knocked the colour-classifier out of whack. Presumably everything now has a slight tint or something, which will need re-calibrating out.