Knocked the full size one out in just under 8 hours.
Think it's the current record :-)
He3d k200 0.3 layer height 150mm/s print speed.
They are brilliant, current have three in decreasing size.
The one I made for bb's (2 inches high and wide) has issues with the spiral, has splits at the bottom the bb's get stuck in. At some point I'll load a smaller diameter nozzle and print it again.
The one for .38 (9.5mm) ball bearings is great and so is the one for 5mm ball bearings.
Now, I've shown it to lots of people and nobody can explain how it knows which track to pick.
If you use a single ball it will cycle through the 4 tracks in turn. It does not matter how fast or slow you turn the spiral, or if you stop turning while it goes down the track. It always, without fail runs through the tracks in sequence.
Please tell me why this happens, it's driving me mad trying to work it out !!!!!!!