All New Daleks

You may recall that I've been planning to make a small Dr. Who scene on the model railway involving Daleks.

So now I've got a large Dalek Death Squad ready for my model trains. You may remember this old post about our first shot at 3D printing small Daleks. Well things have moved on a lot since then!

Franc's mastered his 3D printing skills and found a way to make finer steps in the printing process to make an new and improved set of Daleks for me. I've been straining my eyes and using a binocular head mounted magnifier to paint them. Yes, it all sounds a bit freakish but the results are awesome.

Here's the raw material from Franc:

I then mount the individual units on the handle of a small hammer using blu-tack to paint them.

And here they are with the Tardis on my old MacBook.

Finally - the tramway has a road surface

I've finally completed (most of) the roadway on which the tram now runs. I have had to very tightly fit my home-made cobblestone paper to the tracks. You may recall that I had built up the roadway around the tracks using cork strips. I've now covered those with carefully cut paper.

The main issue was cutting to fit the curves. There's no way this can be done easily by hand. What to do?

Well, modern technology (and Franc Carter) to the rescue. I asked Franc to laser cut some guides to cut out the road surface curves. He kindly cut them to my spec out of MDF and I've used them to cut out curved sections from the cobblestone paper.

I reckon it looks excellent. Better than commercial tramway stuff! It fits really well and I reckon eooks pretty good even up close.

Photos of the tram

I've added a few photos of the tram in front of some buildings just to show how the bprinted cobblestone paper looks with the tram on it and some buildings in the background.

I reckon it looks super!

A little landscaping and a tunnel portal.

The model railway is a complex layout in some ways and has a lof of tunnels running at many levels. It's also got the town sitting alongside the tram track. I've made a big effort to line all tunnels with heavy black card and I've done a light paintjob in areas inside the tunnels along the trackwork in a wash of black to get things looking more like a real railway. I have yet to ballast and will be doing light ballasting in more exposed areas "underground" and heavy ballasting everywhere else.

I've also fully levelled the area under the buldings in the town using the same thick black card.

All the tram track has been "filled" with plasticine to make it look more road like. I'll be using cobblestone paper to make the current cork look more road like at each side of the track. More on that later.

All of this has left me in a position to begin more serious landscaping. In order to dip my toe into the water in a small way I've started building the slope up to the left of the main station. In order to complete this area I've had to construct a triple track tunnel portal. I did this simply using brink paper (see here) covering a carefully cut out piece of polystyrene. I added details by covering balsa strips with brick paper and gluing it on. The tunnel arch was reinforced with individually cut out strips of card one bring high which I've arched over the mouth of the tunnel.

Making roads, bridges and tunnels...surfaces

I'm readying myself to make a bunch of stuff for the landscaping and I realised that I need decent stone surfaces for roads etc.

Buying this stuff readily in Sydney is pretty hard and when you do find it, it's quite expensive. Why not use by Canon bubblejet and some matte photo paper and just print exactly what I want?

Google to the rescue...

I did a few searches on Google for Cobblestones and so forth on the Images section and found these:

I then used them as textures to fill rectangles in MS PowerPoint and produced this sort of result (PDF).

And now it's all running nicely...

I've finally wired in the Arduino Mega 2560, the Pololu servo controller, a relay board to control the track blocks and the L298 motor system to drive the trains and the tram. 

It's all nicely tucked away under the layout and finally all trackwork is in place and a demo program is running which allows the train to run on every track section, exercise all the points etc.

I'll post more still shots later but for now, here's a video...




Next will have to be the 'real' software which allows for 3 engines to run on the layout at once.

All Torque No Action?

...or maybe when too little torque is, well, not enough, perhaps? No, not really.

I'm trying to control 2 points with one servo and it just proved too hard.

I did an experiment today inspired by a friend of mine - Mr Merrigan. I have a number of points for switching lines which really can only move together (unless you enjoy derailment).

Chris suggested trying to make thes emove usnig a single servo. Well, I had a red hot go at this on Saturday and a good part of Sunday morning.

The idea it to mount the motor roughly in the mid-point of the meeting switches and have a beam going out across both switches with rods hooking into the cross-bars of the switches. One motor, two moving switches in synchronicity.

You can see the servo above and the spar above that with a nice mount point for the motor.

Just to make this a bit more obvious I have mounted the spar on top of the tracks so you can see how it would work. I've also put a videoon YouTube where I show the movement by hand.

Now this looks like a great idea but in fact it does not work well for a lot of reasons:

• You need very careful alignment to make this work and that is not insurmountable but is hard.

• The motion of the corss bar is straight across but this is radial and so puts more strain on the motor at the extremes of the switch positions. That's not a problem - just use a big motor. But that means a $20 motor instead of 2 x $4 = $8 :-(
  
• The long central spar (15cm) means that even a small turn of the motor (1 deg)  results in a big movement, so your points no longer switch nice and smoothly.

I tried and tried but no luck. When I thought through the logic I realise it was a dead loss really.

For all of these reasons, I'm moving back to one cheap servo per point. Sorry Chirs, nice idea though.

I've got my servo mounting system down to about 10 minutes per point.

Of course, there are other ways to do the mechanism so 1 servo will drive 2 points but it then takes more than 10 minutes per point to mount!

Some video of the new layout.

I've been running my engines using a very poor old wower unit. I got really tired of it today and did a quick hack job on an Arduino system to run 2 trains using 2 pots to control spped and direction. Nice and easy - took me 20 minutes total.

Anyway, here's some nice videos of it all running...