Natural Wood

As I mention in my previous post, when it comes to painting I much prefer those models where I can simply block paint in single colours. I can add a little detail with dry brushing, but I'm not particularly good at mixing paints to achieve a natural look; one of my main problems is choosing the right paints to start with. Given that most of the wagon is bare wood I knew I would need something slightly more convincing than the wooden floor I achieved on the workman's coach, so I went on a hunt for some wood coloured paints.

My local model shop stocks Humbrol, Tamiya, and Model Color paints, but out of all three ranges they only had one Model Color paint that contained the word wood; Natural Wood 70.834. Obviously I bought this one, although I also picked up some dark sand, brown sand, and khaki as a tutorial I'd read recently suggested these colours could be used to represent wood. Looking at all four bottles I wasn't convinced any of them were really wood coloured.

My first impression of all the paints wasn't encouraging, but I did notice that the natural wood appeared to be fairly transparent, and in fact a quick web search shows a number of shops where it is labelled as transparent even though the label on the bottle makes no mention of this. Given it's transparent nature I wasn't particularly convinced by it, especially as it would require quite a lot to cover a surface. A bit of experimentation though showed that I could get some interesting effects depending upon what paint I applied under it. After playing around for a while I came up with the following really simple approach to painting the wood and while it probably isn't particularly novel I think it is worth documenting, at least so I can remember how I achieved the effect when I want to repeat it in the future.

So the approach requires just three paints; a white primer, the Model Color Natural Wood (70.834) and Model Color Black Shade Wash (73.201). I started by priming the wagon using a aerosol can of cheap white auto primer to act as the base colour. Once this was dry I used the black wash to help pick out the detail (gaps between the boards etc.) and to provide some shading variation. Once that had dried I then brushed on the transparent natural wood. For both the black wash and the natural wood I brushed the paint across the model following the planks so that details didn't cross planks too much. As you can see, in the top right photo, this is already starting to look fairly good, but I repeated the process a second time (black wash first and then the natural wood again) to build up more layers and details. Given that both paints brush on well and dry as very thin layers you can add a number of layers before you run any risk of obscuring the molded details, but I found just the four layers (two of black two of natural wood) gave me a colour and pattern I was happy with. I then painted in the rest of the details and finished the model with a quick waft of matt varnish, which helps to tone down the final natural wood layer slightly.

I'm sure there are many other ways of achieving a similar effect (I know Paul has used Lifecolor's Weathered Wood acrylic set to good effect) but for shear simplicity I quite like this approach and I think I'll be using it again in the future.

8ft Freelance Flat Wagon

So having designed and had printed some simple flat wagons for use on the new layout the next step was to paint them. So far I've just done one of the three I had printed due to a mishap with the primer which has required the other two to be stripped back. Anyway here is how the first one turned out.

The light in the second picture makes it look a lot more yellow than it really is, the first photo is a more accurate depiction of the colouring. When painting I'm usually happiest with big blocks of a single colour but I new I couldn't get away with that for the wood this time. I'll blog about how I actually produced the effect separately but I have to say I'm quite happy with how it has turned out. As I said in the previous post, if you happen to want one I'll happily sell you as many as you want!

Something to Pull

Having taken delivery of his shiny new locomotive the factory owner had really enjoyed running it backwards and forwards along the short line he had had laid within the confines of the factory. While seriously fun to drive, he was aware that he had, at least partially, bought the locomotive to be useful and to help move things around the factory. Unfortunately there wasn't much room in the cab to carry things so he needed some wagons. He didn't need anything fancy, at least to start with, just a few flat wagons that boxes and sacks could be stacked on so he made a visit to the factories workshops.

The friendly engineer who ran the workshops was fairly certain he could build a wagon or two for the bosses new toy, but he wasn't sure about the wheels so he ordered some from a Scottish company he'd done business with in the past. Once the wheels, all 20 pairs on axles, had arrived the engineer set about measuring things. First he measured the wheels, then he measured the locomotive and the track, then he set about drawing a design for a wagon; something the lads who worked for him could bodge together from the timber laying around and a few metal parts. A few days of sawing, bolting, and general work later and the engineer had three completed wagons in front of him that just needed a lick of paint before the wheels could be slotted into place.

Okay so now that the backstory behind 77 Box Lane has been fleshed out a little further we can return to reality. Now I'm sure I could have bought kits to make appropriate wagons but I decided to have a go at doing some 3D printing. As some of you will know I've had plenty of success with 3D printing OO gauge models, although last time I tried to print something to run on 9mm gauge track, an N scale wagon, I didn't have quite so much luck. Having recently used 3D printing to fix my fridge, I thought I'd have another crack at creating a model to run on 9mm track, but with the added advantage of modelling at 4mm scale where the supporting structures would be twice as thick as when I tried the same in N gauge.

On previous occasions I've created models based on what I think looks right rather than how I think it would have actually gone together. This works okay but doesn't give you any real insights into how you might actually have built the original item, or how you might build a similar model from modelling materials. This time I took a slightly different approach. I created the separate parts (planks, bolts, brackets, etc.) and then duplicated them as needed to essentially build a virtual kit of parts which I then assembled into the final 3D model. I'm not sure if this is a better approach or not, but it seems to have worked in this instance.

Yesterday's rather abstract post showed the three wagons (I grouped three into a single model for printing purposes as it was more economical than printing separate wagons) being cleaned. The models are printed in what is known as Frosted Ultra Detail material which is always covered in the remains of the oily support material when it arrives and this has to be removed before you can paint the models. I've found that soaking them in warm lightly diluted washing up liquid works well. I've checked and the 5.1mm wheels I ordered fit perfectly, but I'll hold of showing you them fitted until I've painted one.

I am, however, happy enough with how they have turned out to make them available via Penistone Railway Works, so if you fancy a simple, reasonably priced, wagon or three you know where to go!

Coming Soon...

Action at a Distance

So I've done a bit more work on the point control in that it will now actually throw an OO9 gauge point. This is achieved by attaching the servo arm to the point tie bar using some 0.5mm diameter piano wire running through some 2mm diameter aluminium tubing (both from Albion Alloys) to keep it in place; i.e. a proper wire-in-tube system.

Everything is currently just held down with double sided tape but that seems to hold well enough for experimentation. I could have glued the point down though as I won't be using it on the layout having damaged it beyond repair when soldering on the wires (one of the sleepers is so buckled that the switch rails don't line up so things derail) but it works for this purpose. I found using the second hole from the end of the servo arm and a rotation of 10 degrees was enough to nicely throw the point. The calibration was a bit hit and miss though so I need to work on the software on the Arduino to make that a bit more user friendly but so far I'm happy with how it is all working. If I can figure out how, I might slow down the action to be a bit more prototypical, although that might be tricky given that I'm still relying on the spring in the points to help complete the throw.

Next up will be checking that I've understood the frog switching wiring correctly by attaching the three wires from the point to the relay and checking for the expected power flow through the point.

Preparing To Throw An Electrified Frog

Please note that no amphibians were harmed during the production of this blog post!

I'm afraid that now the disclaimer is out of the way, the rest of this post will probably turn out to be quite boring in comparison; the title is accurate but rather misleading.

While I may have finally settled on a plan for the new layout (and no one highlighted any obvious problems with it) there are still a few other things to sort before I can start laying any track. The main outstanding issue is the matter of how the points are going to be controlled.

On Jerusalem I used a wooden dowel as a manual point control (think of it as a poor mans wire-in-tube control). This approach is both cheap and simple but it does have a few down sides. Firstly it can't be operated automatically and on Jerusalem at least I can't reach the lever to operate the point while stood at the front of the layout watching the trains. While I could fix one problem by extending the control so it could be operated from the front or the back of the layout that still doesn't allow me to control it automatically.

The other problem with the points on Jerusalem is that they rely on the switch rails to transfer electrical power and I've found that this really isn't very reliable, especially once they have been painted and ballasted, no matter how well I try and clean them. Many layouts solve this problem by switching the power externally to the point, often by a micro-switch connected to the tie bar so that changing the points changes the polarity of the frog (the frog is the point of the vee where the two lines leaving a point meet).

Given my current plan for powering the tracks I decided to try and create a simple electronic circuit that would combine changing the points with switching the track polarity. To produce the mechanical movement necessary to change the points I've opted to use a small 5v servo although I have yet to finalize exactly how I'm going to mount them to the layout and connect them to the points.

If you switch the track polarity using a normal switch it needs to be a SPDT (single pole, double throw) and such switches are also easily available as electromechanical relays. I thought they should also be available as integrated circuits which would draw less current than a relay, but after a long search and a long discussion on the MERG forum (sorry, but that is only accessible to other MERG members) it turns out that if such an integrated circuit does exist it would be prohibitively expensive to use.

So what I now have is a simple Arduino powered setup that on a button press will switch a relay and move the servo arm. I'm actually using a double pole, double throw (DPDT) relay as that opens up a few options which I'll return to in a later post. Anyway here you can see the whole thing in action.

Each time I "press the button" (rather than a button I'm just pulling the pin low by shorting it to ground) the servo switches to the other position and the relay changes over; hopefully you can here it click in the video over the servo whine. I've currently got the servo switching between 45 and 135 degrees so there is obvious movement. Obviously I don't need that much movement to throw the point, so this will need configuring once the servo and point are connected. You can also see that the light on the Arduino goes on and off to signal the position of the servo and state of the relay, which will be useful on a control panel for showing the position of the point. At some point I'll remove the need for the Arduino (like I did for the flickering fires in the mill on Jerusalem).

While it might not look like much, I'm quite happy with how it all works as I can see how I can combine this with some other ideas into an integrated control panel which should give me both full manual control over the layout as well as the possibility of running some trains automatically. Next up will be connecting this up to an actual point and configuring the servo properly.

Loading Gauge

I've always thought that the carriages in France end up much closer to the platform edge than they do in the UK; I've no idea what 'Mind the Gap' is in French, but I've never heard any such announcement even when they are also given in English. This photo from Wikipedia shows what I'm talking about. Such small clearances mean that if you want to introduce new locomotives or carriages to the network you need to ensure they fit within the specified loading gauge. This is the same for modellers as it is for the real railway; you may remember that the carriage I received as a birthday present only just clears the tunnel on Jerusalem. While changing a model can be frustrating and relatively expensive, clearly a similar problem on the real railway would be exponentially worse.

Amazingly not accurately checking the loading gauge is exactly what led to a number of news reports today. Here are some quotes from the Reuters article:

France's national rail company SNCF said on Tuesday it had ordered 2,000 trains for an expanded regional network that are too wide for many station platforms, entailing costly repairs.
...
The RFF only gave the dimensions of platforms built less than 30 years ago, but most of France's 1,200 platforms were built more than 50 years ago. Repair work has already cost 80 million euros.