Plastic Locomotive Kits - A discussion and views to the future

[brack]

Wsf could be used for chassis but it is not dimensionally accurate enough to rely on it. I've 3D printed chassis blocks with pulley/layshaft/worms and FD/FUD is good enough to get them meshing correctly each time and the bearings to be a push fit in their printed holes and recesses. WSF is not accurate or reliable enough, or at least wasn't 5 years ago when I trialled different materials.

I do think that for a rod coupled chassis using a gear motor and bevel gears is the easiest solution. For a chassis without coupling rods you're probably best using a layshaft drive and the tenshodo worm/gear sets. If we had more space to play with (o gauge) then gear motor and delrin chain drive to axles would be my choice.

The only downside in my opinion to using the cheap gear motors is that you can't get much of a flywheel on them - they're either single ended with gearbox stuck on the business end, or the 10x12 flat can ones have a short 1mm shaft sticking out and the motor would likely struggle with a flywheel of sufficient size to make much difference.

[Ravenser]

Wsf could be used for chassis but it is not dimensionally accurate enough to rely on it. I've 3D printed chassis blocks with pulley/layshaft/worms and FD/FUD is good enough to get them meshing correctly each time and the bearings to be a push fit in their printed holes and recesses. WSF is not accurate or reliable enough, or at least wasn't 5 years ago when I trialled different materials.

I do think that for a rod coupled chassis using a gear motor and bevel gears is the easiest solution. For a chassis without coupling rods you're probably best using a layshaft drive and the tenshodo worm/gear sets. If we had more space to play with (o gauge) then gear motor and delrin chain drive to axles would be my choice.

The only downside in my opinion to using the cheap gear motors is that you can't get much of a flywheel on them - they're either single ended with gearbox stuck on the business end, or the 10x12 flat can ones have a short 1mm shaft sticking out and the motor would likely struggle with a flywheel of sufficient size to make much difference.

 

 

Noted that WSF isn't suitable - I've no background in 3D printing so wasn't aware of the accuracy issue. As FD/FUD would require less clean-up anyway, it sounds as if printed chassis in FD/FUD might be a very powerful approach.

 

The thought occurs - would providing 3D printed chassis to fit under existing kits be a viable approach? I would have thought the chassis part would cost a similar amount to an etched chassis - or for that matter the wheels and motor you'd need to buy, so it would open up kitbuilding to those who struggle with chassis building

[Northmoor]

 

 

Triang made over half a million of the Princess Elizabeth Pacific

...Of which about quarter of a million are listed on ebay at any given time (usually as Rare/Collectable).

 

Your post is very useful and I agree motorising of Kitmaster/Dapol/Airfix locomotives didn't become the standard for the hobby.  However, they do demonstrate the market for static locomotives.  Not everyone wants or can afford a shed full of Bachmann 9Fs, but one or two runners and the rest can be sub-£10 "filler".

 

I can think of one or two potential prototypes for a plastic-static, but I'll say no more because it's quite possible I might be able to commission one in the near future.....

[kevinlms]

.... well, marketed anyway - whether successfully is another matter; it didn't last long.

 

The motivation behind UK CKD was avoidance of purchase tax.

 

Regards,

John Isherwood.

The same reasoning applied to the US market. Athearn (and others) did pretty much the same with their 'shake the box' kits. Often all there was to do to assemble a 'kit', was to clip on the handrails and jobs done.

Their diesels locos ran very well with the central motor drive & gear towers in the bogies. But of course, they did at earlier times have the rubber band drives, with the 'road runner - beep, beep' type starts & stops.

[PatB]

The same reasoning applied to the US market. Athearn (and others) did pretty much the same with their 'shake the box' kits. Often all there was to do to assemble a 'kit', was to clip on the handrails and jobs done.

Their diesels locos ran very well with the central motor drive & gear towers in the bogies. But of course, they did at earlier times have the rubber band drives, with the 'road runner - beep, beep' type starts & stops.

I do look wistfully at Ebay listings for the old Mantua/Tyco steam loco kits. Their fidelity to prototype might be questionable but those huge, cab filling motors and massive die cast shells suggest a finished product that will climb a 1 in 20 with 100 axles behind the tender .

[doilum]

I have really enjoyed reading this old chestnut. Speaking as a 7mm outsider who embraced the black art of soldering many years ago, I am constantly amazed by the ever expanding range of 4mm RTR locomotives that appear on the club layout. If the Beattie well tank has been done, what is left to do?

Your wish list?

A J84 or N19 perhaps?

[alastairq]

If we all went back to running the older Athearns.....would the National Grid be able to keep up?  

[cctransuk]

You can't laser cut plasticard, but there are some wagon kits available in the style you suggest. At least in N Gauge. Mill Lane Sidings did a BR Ferry van and a few other kits in laser cut card, and Osborn's Models do a few GWR wagons, like the Beetle cattle van, in laser cut ply.

 

But then you're against the issue that you're replicating an etched kit in a material that is less suited to handling and less stable over time. Plus it's more expensive per unit, if you're making more than a handful.

 

When it comes to things as complex as locos, if you've got the cash to research and tool an injection moulded kit, you might as well instead tool an RTR loco. The cost isn't THAT much more, but you can sell the RTR loco for many times the price that a plastic kit would be able to command.

 

J

 

This issue all hinges around an apparently widespread conviction that 'I can't / won't solder'.

 

I know that this is a genuine belief / fear, but it is extremely limiting for the individuals concerned and, frankly, is not going to be overcome by any amount of wishing for Airfix-type kits in injection moulded polystyrene. The financial considerations just don't add up for locos, and to a large extent, coaches.

 

If a fraction of the mental energy that is devoted to wish-listing alternatives to assembling etched brass kits was devoted to facing up to the fear of / aversion to soldering, there'd be a lot more varied locos and rolling stock around.

 

Threads such as this one are all very well, but they're never going to come up with a magic bullet that will change the fact that metal kits will always be the only viable method of producing short-run locomotive kits; (at least until 3D printing becomes MUCH more sophisticated - and even then, you can't produce a functional chassis without soldering).

 

Regards,

John Isherwood.

Edited March 11, 2018 by cctransuk

[doilum]

Back in my 4mm youth, I found an unstarted, and at the time,unavailable Airfix J 94. I paid £15 for a Bristol models RTR chassis and replaced the footplate with one cut from 3mm steel.

In those days a pound easily paid for two pints of premium larger and a packet of crisps.

[Northmoor]

Jol is (IMHO) spot on about the backup required. In response to a barrage of "I can't work out how to put the pre-made handrails into the pre-drilled holes in my loco cabside" wails on forums, I wrote up the process on a couple of ViTrains models. My guess is that the makers would find themselves with a postbag full of badly assembled models with demands that these be sorted out. All you've done is move the manual labour from China to the UK. Yes, you can put a caveat on the box, but in the same way, modellers think their first port of call for a faulty model should be the manufacturer rather than the retailer, that will get ignored and social media will fill up with complaints.

I've commented before on RMWeb to Tony Wright that while people (that includes me!) are amazed at him building a locomotive to the standard he does, I find people are baffled when I say I have changed the oil on my car or even a headlight bulb.  The proportion of people who can do what was normal DIY a generation ago, is declining fast.  This will always be one of the biggest threats to the self-build market, the general public no longer expect to do things for themselves.

[bike2steam]

I've commented before on RMWeb to Tony Wright that while people (that includes me!) are amazed at him building a locomotive to the standard he does, I find people are baffled when I say I have changed the oil on my car or even a headlight bulb.  The proportion of people who can do what was normal DIY a generation ago, is declining fast.  This will always be one of the biggest threats to the self-build market, the general public no longer expect to do things for themselves.

 

Yeah, true to a certain degree, in the late 60's / 70's & early 80's I spent the greater part of my spare time working on my own, and others, cars, and motorcycles. In those days it was easier, not so much gubbins ( and today, a bloody computer ?) under the bonnet, - now I open up, scratch me head, and slam it closed again. 

Edited March 11, 2018 by bike2steam

[doilum]

Change the oil? Was that before or after you fitted the gearbox? You now need a code reader to cancel the warning light that tells you the light has failed.

On the original topic, in 7mm, there was the 85a Models Hunslet 15". This was a supersized airfix kit with a bespoke RTR chassis. Just what everyone had been asking for. Long out of production, it's creator resisted calls for its reintroduction, and none else felt it viable to offer a similar product.

Today the introduction of RTR products from Dapol and Minerva have made scatch building look expensive.

Whilst the 85a model is still a good model, outstanding in it's day, the thickness of plastic always looks clumsy compared to etched brass.

[jjb1970]

The reason people don't work on their cars anymore, other than the complexity of modern cars, is that they don't need to because they are so much more reliable. Personally I don't see that as a bad thing.

[doilum]

Swapped the MGB for an MX5 and the trolley jack hasn't moved scince.

[Marly51]

This issue all hinges around an apparently widespread conviction that 'I can't / won't solder'.

 

I know that this is a genuine belief / fear, but it is extremely limiting for the individuals concerned and, frankly, is not going to be overcome by any amount of wishing for Airfix-type kits in injection moulded polystyrene. The financial considerations just don't add up for locos, and to a large extent, coaches.

 

If a fraction of the mental energy that is devoted to wish-listing alternatives to assembling etched brass kits was devoted to facing up to the fear of / aversion to soldering, there'd be a lot more varied locos and rolling stock around.

 

Threads such as this one are all very well, but they're never going to come up with a magic bullet that will change the fact that metal kits will always be the only viable method of producing short-run locomotive kits; (at least until 3D printing becomes MUCH more sophisticated - and even then, you can't produce a functional chassis without soldering).

 

Regards,

John Isherwood.

I’m one of the Forum members who is still unsure of her soldering skills, but getting there and looking forward to having a go soldering the metal kit of a Highland Railway footbridge - I believe it is quite fiddly! Plastic kits have been useful for me up until now and I will still use them where time may be a factor. I look forward to a having a better of knowledge of locomotives and attempting my first kit. Plastic kits were a good introduction to the hobby for my brother and myself when we were youngsters. Edited March 11, 2018 by Marly51

[doilum]

Practice is the only way to progress. Invest a fiver on a small sheet of thin brass. Start with something simple and achievable, a lineside ballast bin perhaps. Learn to cut true rectangular parts and join them with the minimum of visible solder.

Move on to your scrap drawer. Take that long abandoned Nellie or Pug and have a go at making a new cab in brass.

This might take several attempts, but you have a whole sheet to go at. Once happy, you can either glue it on to the plastic, or continue to clone parts in brass until you have your first loco body.

The secret is to practice on something disposable

[grahame]

Back in my 4mm youth, I found an unstarted, and at the time,unavailable Airfix J 94. I paid £15 for a Bristol models RTR chassis and replaced the footplate with one cut from 3mm steel.

In those days a pound easily paid for two pints of premium larger and a packet of crisps.

 

So at today's RTR chassis price in pints (£15 then buying more than 30 pints) that would mean that it would now cost in excess of £90. Sounds (tastes?) about right. I'll drink to that.

 

G

[Jeff Smith]

Successful soldering does require appropriate melting point solder, really low for white metal, medium for brass/nickel silver, and normal multicore for electrical work. The first two also require a liquid flux, usually the same type works for both for me. If coming to grips with these relatively simple concepts is daunting then stick to styrene or card but the possibilities open up considerably if metal can be satisfactorily joined. A variable temperature soldering iron is also useful but not essential - my first white metal loco, a Ks 57xx was built using a regular 35w iron, you just have to be quick....

 

Unfortunately US modellers seem to not solder much so low and medium melting point solders are not readily available, I have to import mine. The best I can get is a 135c melting point, 20x3 inch sticks about 2mm diameter for $19.....flux is easy and cheap once I found the stuff used by stained glass hobbyists, is also relatively non-toxic. The lack of really low melt solder is strange as there are a few white metal kits over here but superglue is expected to be used.

[Northmoor]

The reason people don't work on their cars anymore, other than the complexity of modern cars, is that they don't need to because they are so much more reliable. Personally I don't see that as a bad thing.

Yes that is true to a degree, they don't make them like they used to - Thank God.  However this reliability has I think led to complacency; I cannot believe the number of <5 y.o cars driving around with lights out, illegal tyres etc.  I know many people who never do any maintenance (or even basic checks) between MOTs, so their broken light could have been like that for 51 weeks.  

[Butler Henderson]

so their broken light could have been like that for 51 weeks.

Stupid car design does not help - on Renault Megane Mk2s the front lights are accessed from the front wheel arch while a third generation Seat Ibiza completely baffled me in requiring the plastic front of the lights to be pulled off - no way would it budge, took it to the garage - oh yes that's the way it comes off - mechanic comes out and tugs at it, tugs it again and again and... until he flew backwards hitting the deck on his back with a bit of a scream but he had at least got the part off!

[PatB]

The reason people don't work on their cars anymore, other than the complexity of modern cars, is that they don't need to because they are so much more reliable. Personally I don't see that as a bad thing.

 

As a mate of mine says about his taste in motorcycles "I used to like Harleys because you can rebuild them. Now I like BMWs because you don't have to".

 

Back on topic, I tend to think that if I can learn to solder (ten thumbs but willing to have a go at most things to add to my self-sufficiency), anybody can, and the constructional vistas even a rudimentary grasp of the skill opens up are just staggering.

 

Edit: Meant to add, but forgot, I've always been rubbish at sticking plastic kits together neatly. I don't think I've ever built one that hasn't had at least one solvent fingerprint somewhere on it. Out of sight is a bonus, but it's always been there. Soldering brass or nickel silver, OTOH, I can be confident that I'm very unlikely to knacker a part beyond redemption. However badly I do it, in the majority of cases the dead solder can be scraped andd melted off, the part recleaned, the joint refluxed and another attempt made. If the worst comes to worst, making a one or two new parts out of flat brass isn't beyond my modest skill set. I can't do that with a nice, injection moulded piece of polystyrene that I've managed to dissolve with clumsy MEK technique. I don't take it as a given that plastic kits are "easier" than metal ones. They might be more familiar and require less in the way of tools but I would dispute easier. Mind you, whitemetal is a whole different ball game again, also considered to be an "easier"  stepping stone along the road to etched brass, and I'd dispute that too .

Edited March 12, 2018 by PatB

[Michael Edge]

Yes that is true to a degree, they don't make them like they used to - Thank God.  However this reliability has I think led to complacency; I cannot believe the number of <5 y.o cars driving around with lights out, illegal tyres etc.  I know many people who never do any maintenance (or even basic checks) between MOTs, so their broken light could have been like that for 51 weeks.  

 

You've obviously never had to change a headlight bulb on a Citroen C5...

[doilum]

Soldering is a skill that needs constant practice to remain competent. I have fully soldered sevenscale pug and Piercy J72 in my cv from 30 years ago, both assembled with low melt stick solder and an 80 watt Wellor iron. Quick dab from a large hot bit technique. This did ot stop me from

[doilum]

This did not stop me from destroying a cylinder end casting on 82004. Lack of recent practice and temporary deprivation of my RSU led to clumsy use of my recently acquired 60 watt iron with tiny bit. The other whitemetal castings were way oversized so a happy afternoon spent making brass replicas.

[Northmoor]

You've obviously never had to change a headlight bulb on a Citroen C5...

My record on a Peugeot 306 was I think, about 90 seconds.  That's from opening the car to release the bonnet to locking the car after checking it worked.

 

The Ford Focus N/S I have got down to about 20 minutes (no, you DON'T have to take the battery out).  I think a Mondeo headlight once took me an hour and a half....