TurboSnail

That's annoying, I was hoping for it to be something far away from the southern region so I didn't have to spend any more money this year... Not only that, but 3 SECR versions - which one to buy? Not quite sure this is what the government envisaged student loans being used for... More info from SEMG here: http://www.semgonline.com/steam/pclass_01.html

I'm using a servo to power the van, as there's really no other way to get a gearbox, motor and esc in as small a space as possible. I've modified it to rotate 360 degrees so it can be used as a motor - I've already written that process up as a blog post (click here to read) so I'm not going to repeat it here. So I need to pick a drive gear ratio... The previous truck I did had a servo drive, then a 2:1 gearset driving the wheels, giving a scale top speed of about 25mph. I want this one to be a bit quicker, maybe up to 40mph. As the other servo was a bit quicker, I'm thinking I'll gear the axle up by about 1.5x to compensate. I'd bought one of those multipacks of cheap plastic gears (58 for £2 seems like a bargain until you realise you'll only ever use 5 or 6 of them), so had a dig through and came up with a 16-tooth gear to go with the 22-tooth servo gear to give a ratio of 1:1.4, which is close enough for me. Looks like it will fit too, the gear has a 2mm smaller diameter than the driving wheels.

For a current project, I need a tiny, but very high-ratio motor and gearbox, so modifying a servo to rotate continuously seems to be the perfect answer. The entire unit takes up less than 20x20x8mm and provides a motor, speed controller (I'm using it with R/C) and an approx. 120:1 ratio gearbox, while costing less than a fiver. But it does need some slightly fiddly modification first. I'm listing the process here, as much to aid my own memory next time I do this... Small but hopefully powerful... After levering off the base, you can see a tiny (4mm diameter) motor (the white circle on the right) and the circuit board. If you move the circuit board to one side, you find the potentiometer hiding underneath. This is what tells the servo what position it is in, so it can adjust correctly. All we need to do to make it rotate continuously is remove this feedback capability. To do this... Lever out the potentiometer so it doesn't have the connecting shaft attached (it has a shaft connecting the pot to the output gear which you can see in the cover to the left). File down or drill out the potentiometer shaft hole (the little white bit sticking out of the small black box in the photo) so the shaft cannot turn the potentiometer. This has removed the servo's ability to sense where it is - there is a better way of doing this for bigger servos by replacing the potentiometer with a two high resistance, low tolerance resistors, which will give you more stability, but I don't have room to do that in this tiny servo body. Flip the servo over and lever off the top cover to reveal the gearbox - be very careful with this or you will have gears everywhere and will have to spend 10,000 years trying to work out what order they went in. I speak from experience... The output gear (the one sticking out the top with a spline on it) will have a tab on the bottom to limit the range it can turn. Cut/file this off. Before you put the output gear back, measure the spline diameter - about 3mm is fairly common. To add a gear to the spline instead of one of the 'horns' that came with it (no idea why they're called that) drill out a gear to slightly less than the spline diameter - drilling this gear to 3mm (by drilling to 2.5mm, then 3mm to reduce the risk of decentreing the hole) results in a snug fit. I used a crown gear as the servo has to sit flat under the chassis so needs a right angle before reaching the wheels. Re-assemble the gearbox and cover, then test - you should have a continuous rotation servo! If it rotates when the control stick is in the centre position, adjust the potentiometer with a small screwdriver until it stays still. If you want, give it a blob of superglue to make sure. The potentiometer can then tuck back into the body as it is not physically connected to the output gear any more, making the installation nice and compact. Job done!

I'm currently trying to upgrade a Hornby 0-4-0 chassis (the cheap one) with one of the Mitsumi motors and a DIY 100:1 gearbox, seems to run well, if a bit noisy, despite having to bodge a 2mm worm onto the 1.5mm shaft using filler... It was a cheap experiment. I got the original worm off using a puller. I want to try adding a flywheel too, to see if I can make the ultimate slow speed shunter out of the 'pocket rocket' chassis. Ultrascale gears seem to be working on similar lines - see here: http://www.ultrascale.uk/node/58 Not sure if they're still going though as their website hasn't been updated in a while and their lead time is currently stated at 8(!) months. They do flywheels though... The only current UK flywheel supplier I could find online is Roxey mouldings but they are expensive for what they are, so you might have more luck with smaller suppliers at an exhibition. I bought a five-pack of these motors for about £3 from some Chinese wholesale website, so now I have to think of some other stuff to make with them... ideas welcome.

Time to get into some more hardcore mods. A while back, I bought myself a Dremel, and have since been trying to justify it, but now I have found a good use for it! The original plastic floor will form the basis of my chassis, but it needs to be flat to a) maximise the vehicle's ground clearance and b) be a good mounting surface for servos and axles. Cue Dremel, to grind off the raised detail you couldn't see anyway, as the truck body is lower. I also had a go at the lower cab back area, to try and increase the clearance for the steering wheels as this was an issue I had on the last truck. Now I have a nice flat surface to work from and motorise, then the body should just drop on top...

Time to test whether I'm being too ambitious again (answer: almost certainly yes). The receiver and battery seem to fit ok, even with the voltage regulator - this is great as I was expecting to have to use a smaller battery. The receiver is tucked under the battery, the only concern here is being able to fit all the wires in place - should be enough space though. Moving on... I'm using a micro servo for to power the truck, and if my theory and measurements are right, it should fit under the floor of the vehicle. This means it will be visible to the observer, but I think I can get away with disguising it as a fuel tank or something. This also makes the build simpler if the servo is part of the chassis. I think this will work... The other servo is for the steering and both just about seem to fit in the space between the wheels. The die-cast chassis and wheels will probably be thrown away, to free up space and also due to the problems I'd have making it steer and adding a drive gear to the rear axle. The wheel mouldings of cheap OO gauge vehicles tend to leave something to be desired in terms of detail and roundness - one of the issues I ran into last time was a wobble created by un-round wheels.

A new project beckons... The Leyland FG will eventually become remote controlled, to join the Albion truck. I chose it as a fun, more toylike model as I don't want to spend too much time fussing over details, rather I want to use this project to iron out a few of the issues I have with the previous attempt. And besides, who doesn't like a fire truck? Anyway, so as not to clog up my blog, I've started a thread on the build progress here: http://www.rmweb.co.uk/community/index.php?/topic/125927-rc-truck-in-oo-scale-mk2/ I think I need to start on a layout with a more extensive road network...

A new project now graces my workbench - adapting a Leyland FG to remote control. This thread will follow the build of the truck (assuming all goes well and I don't ditch the project in frustration) and please feel free to comment with ideas or your own projects as I'm certainly no expert on this (yet). I've done one R/C truck in OO scale before (the Atlas truck pictured), but this builds off it with (hopefully) more functionality and better features and control. I chose the Base Toys Leyland FG DA85 'cos it was cheap, and eye catching, and most importantly had a good amount of empty space inside it. While physically smaller than the Atlas truck, I should be able to package the R/C equipment a bit better having learnt from it. First order of business was to dismantle it, which was fairly easy. It had a dividing section in the middle, so I removed it with pliers - I think most of the interior will go too to make room for the R/C stuff. Not that you could see it anyway, I guess this is a part used in lots of models. Comparing it to the inside of the Atlas truck (I think it's an Albion of some kind, which escapes me for now), there is clearly less space, although some is wasted in the truck by the positioning of the drive and steering servos. If you want to know more about the Albion, see the video below. I'll leave it there for now, after all, I've got a model to get on with...

Lining it up is a bit of a faff, other than that it's quite easy. If you do give it a go, I'd recommend not using the cams I did, as having two different ones made it a bit awkward. The round one seems to work better as you can turn it both ways.

Finally got round to finishing the remote uncoupler installation, which finishes off the track work for now. It's nothing fancy or electronic, just a manual cam-based system made of ice cream sticks and offcuts of wood and metal. This shows how rubbish I am at baseboard planning, having hacked a hole in the supports to fit the system in. Fortunately it's not a wide baseboard, so still has plenty of strength. Lining the whole thing up was a bit of a nightmare, but it seems to work pretty consistently. I tried taking a video with my rubbish phone, but hopefully gives an idea of how it looks. More info in this thread if you're interested: http://www.rmweb.co.uk/community/index.php?/topic/113032-remoteautomaticdiy-uncoupling-methods/

Ok, this really is the last post about roads for a while... But at least it's a video! We modellers always test our track when it's been laid, so why not do the same with roads? The road surface seems pretty good for the truck, it has enough grip although still wobbles a bit - I blame Base Toys for not making round wheels. Need to work on that turning circle too!

The downside of making roads by mixing random paints and chemicals together (see my previous blog post) is that somehow it mixed together into a very even colour. I thought it needed toning down, so I decided to go with a wash of grey, this being the simplest method I could think of. Gaugemaster decided to send me a pot of Humbrol no.32 despite me ordering something else, so some of that went in with some white spirit. Before anything dried, I went over the whole area dabbing it with kitchen roll, which seemed to make the effect more subtle and less uniform. I'll freely admit I was making it up as I went along, but it has turned out quite well. One learning point though: if one dabs too vigourously (with the kitchen roll, not the odd arm thing) the colour rubs off and it then gets very difficult to mix in a new patch without there being obvious borders. That should be it for roads - the benefits of having a small layout. I am now desperately looking for other things to weather before my mix dries up...

Thanks, it was completely free! If I can use/recycle stuff into my layout I find it more satisfying - hence papier mache hills and cardboard box buildings also in the images.

One of the major parts missing from the layout was roads. Lots of people have their own preferred methods, including using fine grit sandpaper, textured paints, Bachmann RoadStuffTM (I've no idea what it's actually called) but all of those methods involve either expense, time waiting for internet orders or going outside, so I had to come up with something else. Following a rummage in the garage, I found the ingredients for the rather noxious brew in the photo below: some dulux white matt primer, most of an old brown tester pot (possibly from the 80s?), some completely solidified GreenScene textured road paint (the dark tarmac, I think) and mixed it all together. At this point, it was still way too white and I couldn't locate any black paint - although come to think of it, I shouldn't be surprised as who paints their house black? Slightly desperate, I came across some car bumper restorer blackening wax, from back when I had a mk1 Ford KA with the grey plastic bumpers, and chucked it in. Amazingly, it mixed in ok, as you can see below. There was just enough Greenscene paint to add a bit of texture to the road without going over the top and having a gravel track. Probably due to the unconventional mixture of chemicals, there were a few cracks in the paint after drying, but a second coat sorted this out nicely. It's not the best looking road I've ever seen, but since it was free I'm not complaining, and the next job is to tone it down and mess it up with some washes to get some more variation in the colour.

It's all a bit too fixed to change the track layout now, but I'm not too bothered about it looking perfect - this layout is intended to help me build my skills before I go on to something more ambitious in the future. Also I needed an excuse to run some stock The backscene is a generic Gaugemaster one that looks a bit like some areas of the South Downs in east Kent, so that's where I've set it. Haven't found a suitable 'might-have-been' justification yet though!

So, given I have some free time in the University holidays, I thought I'd have a go at blogging my layout progress (or lack thereof), for two reasons: 1) 'cos it'll give me something to do with myself and 2) so when it inevitably shows how little I've achieved (I am on holiday after all), I'll be motivated to do more. I'm aiming to do weekly updates as I don't want to be too ambitious but who knows where this is going. Maybe I'll be able to get some video in from time to time as well. Might be worth starting with a layout description: the picture above (or wherever it goes on a blog) shows the layout in it's current state - track down and wired, landscaping done and starting on adding roads, buildings and scenic detail. It is just a small shunting plank layout (how very original!), the only fancy thing about it is live frog points, the first time I've ever used them and they seem to be pretty good considering my motive power is small 0-4-0 and 0-6-0s.

Finally got round to taking a video of the uncoupling thing

Great model, adds a surprising amount of character to the scene for such a simple change. How did you get the corners cut out so neat?

Thanks for all the positive comments! It is a 7805 type regulator, I just used what I had lying around. I didn't think of getting a SOIC version, that would have been so much better, fortunately this lorry was big enough to fit it, but I'll try it next time. The steering mechanism is from here. It's a bit expensive but if I'd made it myself it wouldn't have worked nearly as well, I bought a set of their front wheels too to go with it 'cos the Base Toys ones are a bit more egg-shaped than I'd like... TS

I was inspired by this to have a go at making my own, check out the video: I was using fairly cheap R/C gear so I had to get the biggest lorry I could find to fit it all in, but it's not too bad for a first effort (Probably have to full-screen it if you want to see the subtitles, it looked bigger when I was making it...)

Nice to see all the different approaches! As for mine... Prototype No.1 of the cam system is up and running: Turn the axle and the cam lifts the base, which is attached to the cardboard section between the rails. Simple, and works pretty well too, despite being made from a magnum stick, an old offcut of steel rod, some wire and one of those felt pads you put on the feet of furniture! The lifted bit is supposed to look better, but this is only the mk.1. The next ones will be disguised as wooden walkways across the tracks, which hopefully will be less obvious/ The idea seems to be worth pursuing, though.

Having looked at all the various types of uncoupling devices (Kadee, magnets, hand of God, etc.), I thought I'd see if anyone else has a DIY solution for a bit less money! I'm currently working on a version for standard OO tension locks involving cams lifting a piece of cardboard between the tracks - it's very 'bodgy' and I'll post a few images when the damn thing finally works... So any unusual/novel uncoupling methods out there?

This is my first attempt at a loco repaint, quite possibly the opposite of 'tarted up' as it's the most simple livery out there! SECR No. 751, it has a few mods too, like the smokebox front and the boiler side valves were replaced. See the post here and there's still a few little details to go.