Chief Engineer Henry writes:

“Hello there,

We’re doing ok – slowly, but surely. I’ve been continuing to build & test in the evenings and weekends – I’ve built a ‘unit revolution’ of the new helix, using the original framework but with 00 gauge model railway to convey the postcard, which is supported on cardboard and held in place by some natty adjustable brackets which i’ve built from odd bits of plywood and acrylic which was hanging around.

Attached are some (in build) pics…

The parts were easy enough to make (especially with my natty new tabletop bandsaw) but I’ve been being extra cautious and testing what happens to the structure over time – I don’t want any of those subtle changes that were frakking things up with the last ‘design’.

The brackets need a little more work, in order to induce controllable camber – I think its a matter of a bolt per bracket, connected to the copper pipe.

That way, I’ll be able to ‘dial in’ the amount of camber needed for each quarter of the helix (at the top, too much camber is a bad thing – it stops the truck because it hasn’t started moving very much, at the bottom you need quite a bit – the truck is moving rather quickly and has a tendancy to fly off – more camber required…)

The next stage is to complete the entire helix – which is a matter of manufacturing more of the same standard parts and slotting them together. The helix can then be tuned and the rest of the layout completed.

So, the carrying postcard should be able to decend via gravity. Hopefully the more finite adjustment of the track will mean that this will work fine…. hopefully.

I was giving quite a lot of thought to how the truck would get itself back up to the top – the last meeting with Russell fixed me on having a powered arduino controlled shunter to do the work.

All the other methods seem too complicated in one way or another. The shunter is simplest – it can either be battery powered (with a recharge station at the shop end of the track) or can be powered through the track itself, just like a model railway.

I’m inclined to go for the battery powered option – because then the track doesn’t have to be cleaned (which is a pain in the arse, and will be tricky considering how delicate the track supports will be….)

In *theory* once the helix part is complete, the rest of the track is very easy – about as easy as it was to make that bit of track we built previously. The next complicated part is the postcard pickup, and following that the part that pushes the postcard off the truck at the other end.”