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Rachel's Building gets a proper sign

When I was building "Rachel's Building" for Raparapa, I didn't have time to make a proper sign for the building front and instead just stuck on a sheet of paper!

Of course a girl like Rachel deserves a far better sign, so today I did something about it.

I started by making up a sign in Inkscape and then exporting it as a DXF file. I imported this into Meshcam and turned it into a 3d shape. I then converted it into some GCODE, a process that took about 10 minutes of pure number crunching.

Then I made up a small mold from some styrene and filled it with resin. I let this set, cleaned it up, and loaded it into my CNC machine. I set the origin to the corner, loaded in a 0.1mm engraving bit, and clicked GO.

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Keepalive for the Kato TGV

My Kato "sud est" TGV runs well considering its age, however since then N scale mechanisms have come on a bit, and the orange TGV is lacking in a few areas. Chief would be the lack of flywheels, causing very abrupt stops when the wheels loose contact with the rails. Since two of the eight wheels have traction tires, it doesn't take a whole lot of movement to cause this to happen.

So I decided to have a go at fixing this today. I decided that a small keep-alive circuit might do the trick. The theory is that by adding some capacitors to decoder, they provide a small amount of storage capacity, capable of powering the decoder for a fraction of a second until the engine moves a little further and regains power.

That's the theory. In my parts drawer I have a bunch of capacitors, so I pulled out a bunch and measured them up. The TGV motor car doesn't have a whole lot of free space, so most of my capacitors wouldn't fit. In the end only some 10V tantalums were small enough. ...

Del Prado NS1100 nearly finished

Progress continues on my Del Prado motorization project. It's nearly finished!

Adding Weight

I was a bit worried that the poor thing, with only one motor bogie, wouldn't be able to pull much. So I decided to add some weight. First step was to make up a sacrificial master out of polystyrene. With some careful trimming and cutting, I soon had a weight that fitted nice and snugly over the gearbox and universal.

Polystyrene isn't known for its weighty properties, so I needed to convert it into something a little heavier. My old stand by, white metal, sounded like just the trick. So I made up a mold from some scraps and mixed up some clay and water to make a mold. Here is my fairly crude mold, with the sacrificial po...

Del Prado NS1100 progress

Progress continues on my Del Prado motorisation project. Today I made up two bogies.

Unpowered bogie

Having settled on only one powered bogie, I decided to tackle the unpowered first. Here is the original del Prado bogie. The wheels were interesting, they sort of rotate, and by that I mean the axles are jammed up solid, but the wheels are such a loose fit on the axles that they still rotate. Not ideal!

So out came the chompers and I stripped the bogies down to just their side frames, which seem quite reasonable. A quick brush with the file to clean them up and we're left with:

ArduinoCMRI and RS485

A fun little side project of mine is Arduino C/MRI, a library that lets you easily connect your Arduino projects up to the JMRI layout control software, by pretending to be a piece of C/MRI hardware. Hence the name.

In previous episodes, we've looked at various methods of expanding the capabilities of Arduino C/MRI; be it by using shift registers, or emulating larger boards. But at some point you're going to need more than just one board, and that's where things get confusing.

The logical answer, you would think, is to connect multiple Arduino's to your computer. Simple. One USB cable for each one. The problem is, JMRI is not designed to address more than one C/MRI system at once. Trust me, I've done everything including hacking the XML config f...

Motorising a del Prado NS1100

A new project has landed on my workbench this week. A while ago while idly surfing around I discovered the "del Prado" range of diecast collectable trains. These were produced for a Spanish magazine, one of those ones where every week it comes with a new "limited edition" collectable on the cover and before you get a chance to cancel the subscription the next one is already on your doorstep. Anyway, the del Prado models are quite crude and very cheaply made, but they are mostly to scale and available fairly cheaply on the second hand market. So I did a bit of hunting and ordered a few that I liked the look of.

Today the package arrived and I excitedly opened them up, expecting the worst. To be honest, I was pleasantly surprised. I ordered three models, one each of a German, Swiss, and Dutch electric loco. Sounds like the beginning of a railfan joke. I decided to tackle the Dutch loco first, as it's really quite cute.