A Whole Brass Band

I didn't think I'd have anything to write about today, because I've packed my modelling stuff away for the weekend as we are having family to stay. Fortunately the post brought something interesting for me to talk about.

Some of you may remember that one of the things that grabbed my attention at Barrow Hill last September was the Model Electronic Railway Group (MERG) stand. Having signed up not long after, I received my first journal just before Christmas and found it a fascinating read. While many if not most of the members have far more electronics knowledge than I do, I did notice a lack of articles around using the Arduino to control various aspects of a model railway, something I've been playing with for a while, and so I thought I'd write and submit an article.

In the end I submitted two articles both of which were accepted, and both of which appeared in the journal that arrived with today’s post. The first article explains how I produced the flickering flame effect for the mill on Jerusalem, which I've talked about on this blog before. The second, longer, article focused on how you would go from a prototype using a full Arduino to a cheaper standalone circuit which is probably of more general use (while this was a new article it drew heavily on what I wrote on one of my other blogs, here and here).

Sorry for this being a bit of a trumpet blowing post, normal service will resume after the weekend.

Quarry Hunslet: Joined Up Motion

So having taken the frames apart, cleaned them, put them back together and discovered part of the problem was the frames rubbing on the rolling road, I now have the first part of the motion fully assembled. This involved gluing the cranks onto the axles, threading the bushes onto the crank pins and then the coupling rod. On the rear axle this is currently all held in place by a small bolt (until the rest of the motion is added), while on the front axle the screw has been cut to length and the bush permanently secured in place. There were a few worrying moments where things didn't seem to want to run smoothly, but with a little patience it all seems to be working nicely.

As you can see I decided to paint the cranks before assembly, although some of the paint has clearly rubbed off as I assembled the motion. Touching it up should be easy though once I've assembled the rest of it, and if not a little weathering powder should blend things together nicely.

Quarry Hunslet: Working Brakes

Okay, so there is a slim chance that not all the problems I had with the frames yesterday were down to not putting them together straight to start with (although that was definitely a problem).

This morning I spent quite a while making sure they were nicely aligned both to the footplate and against the wheels before gluing them back together. Once the glue had set, I placed everything back on the rolling rode, and while I got some movement, it wasn't fluid and smooth, but the clearances appeared perfectly fine. On closer inspection I realised that the problem had nothing to do with the clearance between the frames and cranks, this time at least, but that the brake detail on the frames was pressing against one of the rollers which was causing the roller to stick which in turn was stopping the wheel from smoothly turning; in other words it was acting as a brake!

Moving the whole thing off the rolling road and onto the track and it moves nicely. Now I just have to put the coupling rods and bushes back on and hopefully that will be the first part of the motion assembled and working.

Quarry Hunslet: Is This Progress?

So yesterday, with no small amount of trepidation, I set about assembling the motion of the Quarry Hunslet kit I'm building from this scary looking selection of parts. It wasn't entirely a success, but I will say it wasn't exactly disastrous either.

The first step is to add the cranks to one side of the motor unit using the coupling rod and brass bushes to correctly align them with the small nuts used to hold the crank and bushes in place for testing. I managed this without any problems and even managed to glue the cranks in place without gluing anything solid that shouldn't have been. Before trimming the front screw and permanently affixing the bush to the crank I thought it wise to check for smooth running with the frames in place, as there is very little clearance between the frames and the cranks.

Unfortunately this is where things started to go wrong. I set everything up on a DCCconcepts rolling road (I bought this when I first got back into railway modelling last year to help service the OO gauge models that had been stored for so long), so I could carefully watch the movement. I gently applied some power and nothing moved. It turned out that I hadn't got the frame perfectly positioned when I built the chassis and while there was enough room for the front crank to rotate the back one was stuck. I did try gently sanding the back of the crank down a little (not easy given it was glued to the wheel), but in the end the only course of action was to disassemble the chassis to realign the frames correctly.

Fortunately having used super glue instead of solder to assemble the chassis it was fairly easy to break the parts down again. Cleaning the old glue off though would have been a nightmare, but fortunately lunchtime yesterday saw the post arrive, which included a package from Eileen's Emporium. The order had been placed for something else entirely (which I'll come back to in a later post), but on a whim I'd added a fibreglass pen to the order, and this made cleaning up the parts really easy.

I have done a little more work since cleaning up the frames (cranks attached to both sides now), but I'll wait to show you the motion in action until I've got the frames back together and everything working. Hopefully that might be later today but it depends how things go.

A Scary Story

If Stephen King were ever to write a story involving a model railway, I'm fairly certain that he'd use a set of parts like these to drive his protagonist insane:

Quarry Hunslet: Water in, Smoke Out

Only a short update today as there are lots of other things which need achieving this week as well as railway modelling. While the next step, according to the instructions, is to assemble the motion I decided to carry on with the body instead; for a good reason which I'll come back to later.

While the majority of the body above the footplate (ignoring the cab sides) is a single whitemetal casting, there are quite a few detail parts to fit. Today I've concentrated on the water filler cap and the chimney. As with the other parts I've used so far neither of these required much in the way of cleaning before being added, but I did decided to do some work on the chimney. The chimney is a solid cast piece, and while the profile looks good, the very flat top doesn't. This is easy to fix though by simply drilling down into the top. I started with a 1mm drill and then widened out the pilot hole to 1.5mm, down to a depth of about 4mm. This is plenty deep enough to give the impression of a hollow chimney, while making sure the cast piece retains it's strength.

As you can see both castings fit onto the top of a rounded surface, and gluing them into the correct position can be quite frustrating. The water filler cap had a peg on the bottom so I drilled a small dimple into which it could sit and that should be enough to keep it in place. With the chimney I felt that not only was it going to be difficult to position, but that it would be very susceptible to being knocked off. To both help position it, and give it a little extra strength, I drilled matching holes into both the chimney and the top of the smoke box and joined the parts together with some 0.417mm brass wire. There is still some work to do as the joins between both parts could do with filling, but it really is beginning to look the part now.

So with the update out of the way, I'm going to ask for some advice. The main reason I didn't start on the motion today is because I'm unsure how I'm going to paint it. I'm quite happy to leave the coupling rods unpainted, as in reality they are often left unpainted (I might tone down the shine with a bit of weathering powders but other than that...), but the problem is the cranks. On nearly every photo of every Quarry Hunslet they are painted red to match the buffer beams. This sounds like a good idea as they should look good spinning around. The problem then, is at what stage should I paint them? I could paint them before assembly, but the chances are some of the paint would rub off. If I wait until the model is assembled then getting to them, past the coupling rods, will be difficult.

In general the consensus seems to be to fully assemble any model, and then completely dismantle the motion in order to paint the parts. While this might sound reasonable, looking at the instructions for this kit, at the very least the cranks are going to be glued to the axles, and the coupling rods glued to the front cranks, making it impossible to fully dismantle for painting. So any thoughts/suggestions on the best way to proceed?

Quarry Hunslet: Building the Main Frame

I know I said I wasn't going to rush the build of this model, but the combination of a well thought out kit and annual leave means that it's coming along nicely and today saw the assembly of the main frame.

All but one of the parts (the one piece saddle tank, smoke box, and firebox casting) are from the etched nickel silver fret and such is the quality of the kit that they required almost no tidying up before assembly. The majority of the time was taken up with cutting slots in the front and rear buffer beams to allow me to fit couplings. These had to be carefully measured and then I drilled the slots out by hand using a 0.55mm drill bit in a pin vice. Given the thickness of the nickel silver this took me well over an hour, but it was time well spent as I will want to couple the loco to wagons and carriages and there is no way I could have accurately cut the slots after assembly.

For me at least, one of the selling points of this kit is that it can be assembled using super glue rather than having to be soldered together. I'm sure that soldering would produce a stronger frame, but while I'm happy to solder wires together the idea of soldering metal at right angles scares me, possibly more than the thought of assembling the valve gear. So for this build at least, I'm going to stick to super glue and concentrate on getting a free running model. I can't be bothered with doing a video for today's post, but the added weight of the frames and the whitemetal casting have definitely improved the running of the motor unit, and it really is starting to look like a steam locomotive now.

According to the instructions next up is assembling the motion, and in comparison to the four steps in the instructions I completed today, there are 11 stages to assembling the motion so it might take a while before I have anything new to blog about.

Quarry Hunslet: Building the Drive Unit

It's been an unusually productive day on the modelling front. Not only did I experiment with automatically controlling the track power, but I've also found the time to start on the build of the Brian Madge Quarry Hunslet kit that arrived a few days ago.

The first stage in building the kit is to assemble the basic drive unit from it's ten constituent parts (the photo below shows 11 parts as there is a spare drive belt). While the steps are all straightforward the small size of the unit (it's stood on a 1p piece in the right hand photo) makes this quite a fiddly task, but as you can see I got there in the end.

The paint job, especially on the wheels isn't particularly good, mostly as I did the painting before assembly (no point trying to do it after the pickups etc. are fitted) but then of course had to handle the item quite a lot. This isn't the end of the world though, as I can always touch up the paint and, more importantly, very little of what you can see will be visible on the final loco as the outside frames will hide the wheels etc. The important point of course is whether or not it works, and as you can see from this short video, it runs backwards and forwards really nicely (it's being controlled by the same circuit as described in this mornings post)

Motive Power

Those of you who have been reading this blog for a while, might remember that the main motivation behind modelling Jerusalem in N gauge was that I wanted a roundy-roundy layout where I could just watch the trains go by, as I'm not really into the whole shunting business. This preference for just sitting back and watching the trains hasn't changed which leaves me with a bit of a problem, as the new layout is so narrow that it could only ever support an out and back style track plan and personally constantly turning the controller on and off to operate such a layout sounds seriously tedious. To try and solve this problem I've been experimenting with some electronics to see if I can control the layout automatically for those times when I just want to sit back and watch.

What you can see here is my first attempt at controlling the locomotive automatically. The basic idea is that it simply runs the train in one direction for 2 seconds, stops the locomotive, waits for a second, and then runs in the other direction for 2 seconds before repeating the process indefinitely; currently for some reason the locomotive travels faster and hence further in reverse than when going forwards, even though the power supplied is the same.

Given that this isn't a post on my code/electronics blog I'm not going to go into the full details here, but essentially I'm using an Arduino UNO with a L293DNE integrated circuit acting as a H-bridge to provide power to the tracks (the messy collection of wires to the left of the track). Power comes from standard transformer that provides 12V DC at 1.5A, and the speed of the locomotive is set by using pulse-width-modulation (PWM) to vary the duty cycle of the output (i.e. the percentage of the time the power is on versus off). This arrangement seems to work reasonably well, although I have found that the Kato chassis doesn't work as well as I'd hoped at low speed (even with a standard DC controller), although adding some weight to the body shell in the form of Liquid Gravity has helped a little. Interestingly if I put my N gauge locomotive onto the track it performs much better at slow speed. Does anyone have any hints on getting the best out of the Kato chassis (it's model number 11-104)?

Of course basing the change on direction on time is never going to be particularly accurate, especially given that the speed seems to change based on direction, so in practice I'll need some way of determining when the locomotive should stop and reverse direction. My current plan is to re-use some of the ideas from my scale speed trap to sense the presence of the loco at certain points on the layout and then react accordingly.

Another Brick In The Wall

Whilst the photo in today's post may look very similar to yesterday's (including the atrocious lighting conditions), it is in fact an entirely new wall.

While the construction of the wall in yesterday's post went well, I have to admit that I wasn't entirely convinced by the size of the stones portrayed. Given that the wall is a scale 4 feet six inches, that put each of the stone courses at over a foot in height, which seemed overkill for a small wall. I wasn't the only one who thought the stones were two large either (Paul mentioned it in the comments), so I thought I'd have another go.

I still wanted to stick with the same type of stone if I could, so that it would match the factory buildings I'm intending to build, so I simply printed the scalescens.com ashlar texture sheet at 50%, so now instead of three courses of stone there are six, and the wall looks a lot better.

The main remaining problem is that, as Paul also pointed out, the printed stonework looks very flat when viewed up close. While this probably won't be an issue for buildings at the back of the layout (even though the layout is very shallow), it could well be a problem for walls close to the front of the layout. I'm going to try and emboss the mortar lines to see if that helps, but it may turn out that I need to go the DAS clay route in order to add more depth. Of course there is no rush; I'm going to take my time and enjoy experimenting as I build the layout.

The Wall

While the final track plan and layout are still maturing slowly, I have decided that, in at least one place, the factory will be separated from its environs via a wall, and so I thought it worth doing a little experimentation.

Firstly, I'm sorry for the quality of the photo, but I wanted to blog now rather than wait until I could photograph under natural light, so you'll just have to put up with the grain. What you can see here is a short piece of wall that is four feet six inches in scale height; the courses total four feet, and the rounded capping stones are six inches tall. The figure is the driver from the Brian Madge kit that arrived the other day to give you a better idea about the scale. The height was set by the fact that I'm aiming for a wall that school children could look over to catch a glimpse of a steam engine, so I'm not aiming for a large curtain wall of any form.

The construction is fairly simple. I cut two pieces of 2mm thick cardboard which I then wrapped in a printout of the ashlar texture sheet from scalescenes.com. These two pieces were then glued back-to-back to produce a foot thick wall. The rounded capping stones were produced by wrapping the quoins section of the same sheet (the coping stones weren't large enough) around a length of 4mm half round Plastruct (part number 90885). The capping stones were then simply glued to the top of the wall. Simple but I think effective.

I might experiment with different types of stone/brick paper but I think the combination of 2mm card and 4mm half round seems to work well, so that's one more piece of the puzzle sorted.

Well Worth The Wait

Recently my modelling hasn't really produced anything interesting to blog about, mostly because I've been thinking rather than doing. I have two problems to solve before I can really start on building the narrow gauge layout I've been talking about since the beginning of the year; the track plan and how it will be powered/operated. Both of these issues have received some serious thought recently and I'm almost at the point where I'll be ready to share. I did think you all deserved some form of blog post though and helpfully today’s post was very obliging.

You may remember that at the beginning of the year I talked about the two narrow gauge locomotives I wanted to build for the layout. One of those was the small diesel locomotive which I recently finished painting, the other was a Quarry Hunslet steam locomotive that I wanted to build from a kit by Brian Madge. I ordered the kit at the end of December, and it finally arrived today.

Brian was very apologetic about the delay (a problem with the white metal castings apparently), but looking at the parts it was well worth the wait. This kit is, of course, orders of magnitude more complex than the kit from Narrow Planet that I just finished, so I'm going to take it very slowly; getting the valve gear right so that it runs freely is the part that worries me most. I can't wait to get cracking on it though, and fortunately I'm on annual leave next week so hopefully there will be some visible progress for me to blog about.

Distressing

So having assembled the Baguley-Drewry locomotive the next step was to paint it. My plan was to give it a well looked after finish, unfortunately that didn't happen.

The first step was to give it a coat of primer (Humbrol prime grey from an aerosol) which went on easily and didn't show up any areas that needed attention before the next layer of paint. According to the prototype information the loco would have originally been painted "hazard" yellow, with black side skirts and buffer blocks, so for want of any better ideas I'd picked up an aerosol can of Humbrol yellow gloss (I tend to prefer matt but gloss was all I could get). I masked off the side skirts and bufers and sprayed the model and left it to dry. This seemed to work well, and I had a wonderful smooth finish, so I then masked off the upper body so I could spray on the black paint (Humbrol again, this time black satin). Again this seemed to all go well, until I went to remove the masking tape.

When I removed the masking tape, not only did I find that in some places the black paint had run under the tape, but removing the tape had caused the yellow paint to bubble and lift. To say I was distressed was an understatement. My lovely smooth paint job was ruined. In fact I was so distressed that I couldn't bring myself to photograph the disaster before me. My initial plan to rescue the situation was to try and sand back the damaged areas and repaint, but I quickly decided that wasn't going to work well. I could have tried to strip the paint, but I didn't want to risk the metal parts coming loose. So in the end I decided to switch and finish the model in a run down and distressed state.

I used a combination of a small file, T-cut and a a blunted cocktail stick to remove the black paint that had leaked onto the upper body, as well as the badly bubbled yellow paint, and some areas that were actually okay but where I thought rust was likely to form. I then painted these areas using RailMatch dark rust. Once this had dried I then gently painted some water on to the rusted areas before sprinkling on some fine table salt. Once the water had dried the salt was well attached to the model. At this point I again masked off the black side skirts and buffers, before respraying the rest of the body yellow. This was then allowed to sit and dry thoroughly.

Once the yellow was dry I used a cocktail stick (the pointy end this time) to remove the salt grains which allowed the rust colour to show through, although in some places this also removed some of the the rust colour as well. Once all the salt was removed I dabbed small amounts of a rust weathering wash from Flory Models, onto the rusted areas, wiping most of it off with my finger in a downwards direction to simulate water having run across the surface -- I also brushed some of this wash across the black areas as well. The next step was then to use some of the Humbrol rust weathering powder (which was the free gift when I subscribed to one of the model railway magazines) to tone down the rest of the yellow paint so it didn't look like some areas where pristine while others were badly rusted. Final details, such as the window frames and door handles etc. were then picked out, and the makers name badge attached (with a drop of varnish rather than glue as it gives more time to position it accurately), before a light layer of satin varnish was applied to seal the paint to the model. Once the varnish was dry, the windows were glazed (in the same way as I glazed the windows of the lorry on Jerusalem), and then finally the windscreen wipers were fitted. It took me about 45 minutes to fit these, mostly as it took me about 30 minutes to find the one I dropped on the floor!

While this wasn't at all the way I had set out to paint the model, I am really happy with how it has turned out.

There are two things missing before it can be considered fully complete; couplings and a driver. The roof is only a push fit so once I find a driver model I can easily add one, and I'm not going to add couplings until I've decided on the track layout. The reason for this is that if I decided that the track plan is such that the loco will never run around a set of wagons, then I'll only need couplings at one end, at which point I wouldn't bother to fit both couplings, especially as I doubt they will improve the look of the model.

So while the process was distressing (in both senses of the word) I now have a model I'm really quite proud of.