Thursday, June 21, 2018

Clayton #5843 in Ex-Works Conditon

It's been three years since I first started work on a model of Clayton #5843, and in that time I've worked on three different models. The first had issues around the print bending and was never finished. The second was built for running on Rhyd but balance issues meant the heavy pewter driver figure caused the loco to kangaroo along the track, so he had to be replaced by a plastic figure. I've now finally finished the third iteration of the model (another commission so I've still not built one for myself) that includes more weight and finally allows the nice pewter figure from Andrew C Stadden to take it's place in the "cab".

It's new owner has requested it in ex-works condition (so they can have it weathered to match existing stock) and so here it is fresh from the paint shop.


While it would benefit from a little more running in (difficult on my short O14 test track) it's running a lot smoother than previous versions with the driver figure on board and is showing no sign of bouncing along the track.


Now I really should get another set of parts together and build one for myself, but first I'll need to take a trip to the post office to get this one on the way to its new home.

And Smaller We Go...

A couple of posts back I talked about converting the KATO 11-107 to a tiny 4 wheel chassis in the hope it would be small enough to fit a model I'm working on. Turns out that although it's small it's not small enough, not by quite a long way, so I've had to have another look at power options. The result is that I'm trying another well made KATO power unit but this time taken from one of their Centram models.



Not only is the tram model tiny (it's N gauge after all so a scale of 2mm to the foot) but it's been modelled so as to leave the inside empty so you can add your own passengers. This means that all the drive components are hidden under the floor. In fact the model contains two completely independent power bogies which when removed look like this.


Each wheel is just 4mm in diameter which gives you some idea of just how small and compact these are. The circuit boards drive the lights as well as reducing the track voltage to protect the tiny motor, and can be replaced by a simple resistor if you want to make things even more compact.

The problem though, is that when removed from the model there is no connection between the pickups and the circuit board and motor meaning they don't work. The tops of the pickups are the rounded brass pieces sticking up on either side between the wheels. When assembled into the Centram these rub on phosphor bronze strips which connect the pickups to the circuit board which in turn powers the motor.

Now most people solve this problem by soldering wires to the pickups, but you have to be fast. Not only are the pickups touching the plastic casing, but inside the chassis a set of plastic gears run alongside each pickup and they are easily melted if you get the pickups too hot. While you might get two chassis from one model, the model still costs between £80 and £90 (you have to shop around but this is a common price; I got mine cheaper by buying a second hand "as new" model) and so you don't want to destroy a £45 chassis by lingering too long with the soldering iron.

My solution was to design a small clip (which you saw in the earlier post balanced on a 5p coin) which could retain two pieces of phosphor bronze rod which would in turn rest upon the pickups.


It's not the most innovative piece of design work ever but it does the job. The slots for the rod to fit in are slightly undersized, to ensure a tight hold, and directly inline with the pickups so that the rod has to flex slightly ensuring a good push against the pickups. It means that all the soldering can be done away from the chassis and then the rods just clipped in place, and can be easily dismantled again if need be.


You could cut the wires on the chassis and solder them directly to the rods (via a resistor) but I'm going to retain the circuit board for now to use the lighting circuit so I've just soldered on loose wires to prove the system works, which were then wrapped around the terminals on the circuit board. The nice thing is that it opens up using the chassis for anyone who owns a soldering iron no matter how bad their soldering is, without any chance of damaging the chassis, so I'd call that a success even if, as I said before, the design isn't going to win any awards.

Tuesday, June 19, 2018

Test Print

A Shapeways order arrived today so I can restock a number of Narrow Planet kits, but it also included a test print....


I'll explain in a later post, but anyone want to take a guess?

Saturday, June 9, 2018

Power Options

While I've not had lots of time for modelling recently I've been pondering a number of locos that, given the time, I would like to model. As with a lot of the other locos I've modelled in the past these tend to be quite small engines leaving me with few, if any, options for powering them. When I hit this problem with the Hudson Hunslet 24hp diesel I ended up designing a custom chassis for it, and I might still take this route, but in the interim I've been looking to see what existing chassis I might be able to adapt.

The KATO chassis from Japan have a good reputation for reliability even if they can run a bit fast; I've used one in the past when I built my first OO9 loco. Most of their chassis are, however, quite a bit bigger than I'm currently looking for. Or at least that was what I thought until I read a short article by Roger Lycett-Smith in issue 263 of Model Railway Journal (MRJ).

Roger had built a model of a tiny open-cab 4 wheeled Ruston using a KATO 11-107 chassis which starts out looking like this.


Clearly as it arrives, it's not going to be much use for building a 4 wheeled loco. It turns out though, that inside the white casing the motor sits above one of the bogies (which isn't driven) and is connected via shaft and universal joints to the gear train on the other bogie. What Roger had done was to rearrange this setup so that the motor was directly connected to the gear train. My attempt at replicating this resulted in...


Having now done this myself, I've discovered that the instructions in MRJ don't quite make sense. Roger states that...

The power bogie, worm removed from it's carrier and fitted direct to motor shaft, which has been slightly shortened and a brass strip made to secure the motor to the bogie
Unfortunately the shaft on the motor is no where near long enough to pass through the worm, and certainly not long enough to need shortening. In fact if you only attach the worm to the motor shaft it wobbles around quite loose in the housing; this might be partly due to me not having permanently fixed the motor in place but even so I would imagine it might lead to unnecessary wear of the gears if they are moving around too much. My solution, has been to fix the worm to the motor shaft and then insert the original pin the worm was on from the other end. This means the worm is now supported at both ends as before. It also means I have a rotating shaft onto which I'm wondering if I could fit a small flywheel; a job for the lathe next time I have enough desk space to turn it on.

I've not soldered wires onto the pickups yet as I'm considering some more radical butchering to fit the loco I want to model, but I have tested that it runs nicely like this by attaching power direct to the motor terminals.

While it's certainly not the smallest chassis, it has the advantage of being made from reasonably high quality parts which are known to be reliable, and it uses a proper 12v motor. Plus the chassis are cheap; you can buy them in the UK for about £24, although if you are happy to wait you can get them direct from Japan for around £14.

Sunday, March 18, 2018

As Seen In...

Some of you may remember that back in December I completed the I P Engineering kit of a 16mm scale Hudson Skip locomotive. At the time I didn't go into too many details about how I'd built and detailed the kit, this wasn't for any good reason, other than I'd not written anything down. Well now I have and the results are a four page article in the April issue of Garden Rail magazine.

One of the people who read the original post was Phil Parker (if you don't already read his blog then you should) who suggested the editor of Garden Rail would like an article on building such a kit, and he should know given he's the editor of Garden Rail! So over the Christmas holiday I put together a quite detailed article on the build and all the extra detailing, including how I built a rivet press. So if you want the gory details go buy a copy.

Buying a copy of this article is much easier than all the previous articles I've ever written (either railway related or work related) as Garden Rail is sold on the high street so, for example, you can walk into your local WHSmith and pick up a copy. I got sent a copy, but I might even go buy an extra copy just for the thrill of it.

Friday, February 23, 2018

Gunpowder

After dipping my toes into modelling in OO6.5 gauge I decided to see if there was anything a bit more interesting I could model, that might also be usable in OO9 gauge. I didn't have to look far as the Royal Arsenal Railway had an interesting little gunpowder van, which sat on a very similar chassis to the transfer wagon. Mark Smither's book on the railway contains a couple of small photos and a drawing (although I discoverd that the drawing is wrong in a couple of important ways) and I managed to find a few photos of a surviving example which is now at the Conway Valley Railway Museum. Putting these together with the existing chassis model I managed to produce what I think is a really nice little model. First in OO6.5 gauge...


...and also in OO9 gauge.


Design wise the model is a bit of a departure from previous wagons I've designed as in the end I opted for a mixture of 3D printing and etched metal parts. The reason for this is that with the external framing there is no orientation you could print the model in that wouldn't result in support wax covering all the planks, which would likely result in a horrible surface and the plank gaps being obliterated.


The combination of 3D printing and etched parts works really well together on models like this and I'll certainly take this approach again on any similar models in the future.

There are a few issues to finalise but hopefully it shouldn't be long before complete kits for both the OO6.5 and the OO9 gauge versions are available via Narrow Planet, price yet to be confirmed but I'm sure I'll do another post when they do appear.

Friday, February 9, 2018

Stop Blocks

Having previously produced models of the chimneys and finials used on some of the stations on the Lynton and Barnstaple Railway I've now been asked by the same people to look at another set of detailing items; the concrete and wooden stop blocks. While it turns out that they changed quite a lot over the years and no two appear to be exactly alike, research (mostly carried out by Chris Harvey) suggests that there were a few basic versions. Each block consists of a concrete post, some of which have a sloping back, and a wood block which could be either wide or narrow. From those details I've worked up a set of test prints that when painted look like this.


I had to take four separate photos as each stop block is actually made up of two parts that fit together and I only test printed one of each part. Essentially the wooden block has a peg on the back that slides into a slot on the front of the concrete block.


As you can see I've also made it so that an hex nut can be slotted into the concrete part, which not only allows you to use a bolt to secure the two pieces together (not needed really as the parts are a nice tight push fit) but to also bolt the buffer to the baseboard so that it might actual withstand the force of a train colliding with it; the bolt is made from nylon to make it easy to cut to length.

The height of the blocks was carefully chosen to allow them to be used in two different ways. For those who model the L&B and want the block to be the correct prototypical height then they can be mounted on top of the sleepers. If, however, you mount them direct to the baseboard (so the bottom of the block is inline vertically with the bottom of Peco 009 track) then the loop on a standard 009 coupling should just slide over the top of the block with the face of the coupling aligning with the wooden block.

Whilst these were designed at the request of a number of L&B modellers, hopefully they will be of interest to other 009 modellers. A a kit will consist of both a wide and narrow wooden block, a nut and bolt, and either a square or sloped back concrete part (you'll be able to choose which style you want when ordering). I need to order stock before they go on sale but a single kit will be £7 or we can offer a pack of 3 kits for £18.

Tuesday, January 30, 2018

Finally, Some Movement

Having spent some time over the weekend when the little one was asleep doing some work, I managed in return to get a little noisy modelling done yesterday while he was at nursery; I do love having a job that allows me flexibility in when I work as long as the work gets done. The result is that I've managed to move the Clayton O14 loco build along a little to the point where it's now moving under track power.


The downside of more weight is that there is even less space inside than before so I had quite a few problems with electrical shorts, but after some careful tidying and some electrical tape in key areas it moves. Clearly the wiring is just temporary; there isn't room in the loco for all that spare wire but I've left everything nice and long until I sort out the lights and will wire everything up properly in one go at the end. The pickups possibly also need a tweak here and there to improve running, but I'll probably do this once the model is painted as they'll only get knocked when the wheels are dropped out etc. The good news is that with the extra weight introduced in this version it seems to run nicely, although I'll only know for certain how it performs once I try adding the rather heavy driver figure as that was what caused the most problems last time. For now I'm happy with how it's coming along though.

Whilst assembling the model I did briefly ponder another change from the previous version. I managed to accidentally assemble the model without fitting axle bearings. The result, as you can see in the video, was that the wheels were free to rotate slightly around the centre line of the locomotive.


Many models are actually designed to incorporate features similar to this, usually refereed to as a compensated chassis, to help the wheels maintain contact with the track at all times, and hence to ensure proper power collection over points etc. While I did briefly ponder leaving the model like this I decided not to, simply as I was worried that the plastic gear would suffer terrible wear against the stainless steel keeper plate, but has anyone done anything like this before? Any thoughts on how successful or terrible an idea it is?