The future of loco kit building

[Donw]

I am no expert builder and I would tend to opt for a rigid chasis, however I have two locos not built by me one a bulldog has sprung driving and tender wheels and runs beautifully the other a dean goods is compensated. Both run much better than my efforts, the question is does the springing/compensation add much or is it my lack of skill. The only answer is for my next builds to try springing or compensation. What suits you may not suit me!

Don

[Clive Mortimore]

Surely the future of any loco kit must be one with chassis that runs well and can be built wobbly or rigid and in any of the popular gauges. It doesn't matter what material the body is made from or how accurate a model it is if it don't work it is rubbish.

 

Clive

 

PS Never mind if the box looks expensive you will still impress your mates when they visit even if the loco is not made.

[Ravenser]

What is your evidence that more than 1800 people build 4mm kits?

 

The existance of Messrs Parkside Dundas, Cambrian, Coopercraft, Ratio , Metcalfe, Knightwing, DC Kits, Bratchill etc etc not to mention an awful lot of layouts at shows and in magazines featuring kit built items. Far more than 1800 modellers are neeeded to generate all that - I'd suggest you'd be out by an order of magnitude (say 15-20,000: which would onlyt be about 20% of the total hobby - though not all the hobby work in 4mm)

 

The volumes needed for injection moulding imply production runs well into 4 figures for each item (As a basis I believe the 3mm Society needs to order between 500 and 1000 items for a plastic kit mould to cover cost. They aren't trying to make money out of it - so the production runs for commercial 4mm kits must be much larger)

 

 

You did say "kits" rather than "steam locomotive kits": the implication that nobody much outside the Scalefour Society (or even S4 Soc /EMGS) actually builds kits can be disproved pretty quickly by looking at layouts at shows and magazines

[industrial]

Yes there is a lot of rubbish out there what 10 years you could have got away with but rightly these days you should not be able to. Also with computer programs and 3D printing all white metal/resin kits should fit together with no problems as the faults will be able to be removed before the kits come out. This also applies to the etched kits with a test etch built to make sure it all goes together correctly.

 

A good chassis should be easy to build rigid but with beams included and the cutouts marked by half etchings for hornblocks.

 

Instructions should be suitable for the first time builder as well as the edited builders but how much detail history to be included as a large class of long life engines could get OTT as you take the average A3 class engine with different boilers chimney etc through their life.

 

Yes with me there is only one RTR industrial engine and there was only approx 3 built for industrial use with a few second hand ex mainline ones as well this is the Sentinal 100hp 4w VB tank, the MOS 0-6-0 ST IC (J94 to the uneducated) were not a true industrial engine as most likely the class would have never been built just for industrial use as the HE had the 48150 & 50550 0-6-0 ST IC which the latter the MOS were based on so I will have to build most of the engines I need from kits and most likely will always have to.

[Ravenser]

A personal take on compensation:

 

Some form of compensation is more or less essential in P4 for trackholding, even if it's just a fair bit of slop in the bearings of a wagon . I suspect one of the major reasons why British HO failed in the early 1930s is that they had not come up with the idea of compensation , and therefore a dead-scale gauge with deadscale wheels couldn't be made to work reliably . P4 may well owe it's viability to the invention of the concept of compensation (Obviously springing is a second way of skinning the cat, but it was compensation that came to prominence first, in the late 60s /early 70s)

 

Compensation is not necessary for trackholding in OO or EM, though of course it helps. The Bachmann 47/57 , with its very rigid all wheel drive Co-Co bogies is more track sensitive than the usual RTR diesel with a touch of slop and flop in its wheelsets

 

I certainly agree that compensation should in theory provide much better electrical pickup, and this is a very important factor in good running. 8 wheel pickup on model diesels as opposed to 2+2 as given by Lima and Hornby , was a major step forward and a key component of "high spec" RTR , at least mechanically. We used to spend a lot of time and effort fitting extra pickups, and from an outside perspective the pickup arrangements on many steam models looks distinctly inadequete. From a modern image perspective an 0-6-0 looks like a Co-Co diesel so you'd expect pickup from both sides of both tender and loco to get decent results : the "American" system is only what we endured on your average 1980s Lima. A rigid wheelbase 0-4-0T or 0-6-0T looks distinctly dodgy - on a par electrically with my elderly Airfix 31 (pickup off trailing bogie only) though as I think the Airfix 31 has axles with slop it's probably better than the 0-6-0T....

 

So I can see the theoretical advantages.

 

The problem is practical. It is a lot more difficult and laborious to build a compensated chassis than a rigid one. For a skilled and experienced builder , I agree there's going to be no problem, but for a novice making a first attempt a rigid chassis is faster and easier - so he's much more likely to get a result. A compensated chassis may offer better potential results to the experienced, but a rigid chassis though not quite as good in theory is much more easily attainable . Its the old classic trade off of accepting the easier route with the not quite so good result until you have the experience to take the more difficult route

 

To show this is not simply theoretical comment, Exhibit A:

 

 

 

This was/is intended for my Boxfile . The thory was that with lots of points close together, dodgy boardjoint between files, absolute precise control and reliability (dream on) shunting wagons in very small spaces, it would need all the help it could get. Hence compensation, and I was urged that was the way to go anyway. It stalled at this point because I wasn't quite sure I had managed to get absolute freedom of movement in one of the hornblocks , and I was frightened I had somehow managed to assemble the frames banana shape in the horizontal plane - probably something to do with my lens prescription (though a straight edge suggests I haven't) Having soldered up MJT hornblocks, I'm sure it was a vast amount more work to get to this stage than if I'd built it rigid - and I still have to invent the compensation beam arrangement and sourec the necessary bits and successfully improvise it

 

So it's been like this for years: I've got 4 other engines for the boxfile , none RTR but running on Beetles Tenshodos and an old Bachmann 04 chassis , and there are a dozen things ahead of the Drewry 04 in the queue, including DC Kits multiple units running on Replica chassis or with Beetles....

 

On the other hand , a big whitemetal Pacific has loose bits hanging off it fore and aft, and in DC the loco and frames may well be live to one side of the circuit - with pickup both sides on the coupled wheels, a brass wire soldered to the bogie, bearing on the backs of the wheels on one side, an insulated drawbar, and the tender live to the other side of the circuit , and you have all the electrical benefits of compensation without the hassle... Throw in a flywheel on the motor, duties that involve running fast and far non-stop on a continuous ciurcuit with the momentum of a heavy train behind , and I can well see why some very distinguished builders of big green engines for big ECML layouts swear by building them rigid

[N15class]

Yes there is a lot of rubbish out there what 10 years you could have got away with but rightly these days you should not be able to. Also with computer programs and 3D printing all white metal/resin kits should fit together with no problems as the faults will be able to be removed before the kits come out. This also applies to the etched kits with a test etch built to make sure it all goes together correctly.

 

A well designed kit is a well designed kit, whether it is hand drawn or done with CAD. A badly designed one is bad whether it is drawn with CAD or by hand. Just becuase something is done with CAD does not make it any better.

 

What has 3D printing got to do with casting whitemetal etc. What prints I have seen would be no where near good enough for casting masters without a lot of work. Much easier I would of thought to fabricate them.

 

A friend and myself a few years back built the same kit at more or less the same time, We both had trouble with a few bit, but to my surprise it was different parts. Whether it was down to our differing approaches or one of filing off more cusp than the other I do not know. I do not think it was down to the kit. but the way we built. A tighter fold here or there, etc.

[t-b-g]

We habe 3 kit built 0-8-0 tender locos, which run on my Tickhill layout. This is in EM and has 3' radius curves. 2 are sprung and the third is rigid. With such a long loco on tight curves, the flange of the leading wheel runs pretty much against the outside rail. The face of the flange is at an angle, so pushing it against a rail makes it tend to rise upwards. In such circumstances, the rigid one stays on the track better. The whole weight of the loco has to be lifted up and over the rail if it is to derail. For the sprung locos, only a proportion of the loco weight is carried on each wheel. So if the wheel tries to ride up and go over the rail, it has a smaller weight holding it down.

 

So we have to be very careful with the sprung locos and make sure they go in the right track in the fiddle yard. They also only go one way round the layout as they are prone to derailments. The rigid one will run anywhere.

 

All three are just as smooth and don't lurch or bump around anywhere.

 

It doesn't prove anything but it illustrates that springing/compensation should, in theory, improve road holding but that it doesn't alway work in practise.

 

After mentioning that the rigid loco runs better in an article, I got called "the worst luddite since Tony Wright" by no less than Iain Rice.

 

I was quite proud of that!

[James]

With such a long loco on tight curves, the flange of the leading wheel runs pretty much against the outside rail. The face of the flange is at an angle, so pushing it against a rail makes it tend to rise upwards.

 

The same thing happens on tight curves at Scuntorpe Steelworks - we had to remove a flange lubricator which had been installed to ease operations around a very tight curve. It had fallen out of use as it actually aided flanges climbing the rail!

 

After mentioning that the rigid loco runs better in an article, I got called "the worst luddite since Tony Wright" by no less than Iain Rice.

 

IIRC In MRJ 58 Chris Pendlenton mentions he has a a rigid V2 which somehow managed to stay on the track!

[N15class]

We habe 3 kit built 0-8-0 tender locos, which run on my Tickhill layout. This is in EM and has 3' radius curves. 2 are sprung and the third is rigid. With such a long loco on tight curves, the flange of the leading wheel runs pretty much against the outside rail. The face of the flange is at an angle, so pushing it against a rail makes it tend to rise upwards. In such circumstances, the rigid one stays on the track better. The whole weight of the loco has to be lifted up and over the rail if it is to derail. For the sprung locos, only a proportion of the loco weight is carried on each wheel. So if the wheel tries to ride up and go over the rail, it has a smaller weight holding it down.

 

So we have to be very careful with the sprung locos and make sure they go in the right track in the fiddle yard. They also only go one way round the layout as they are prone to derailments. The rigid one will run anywhere.

 

All three are just as smooth and don't lurch or bump around anywhere.

 

It doesn't prove anything but it illustrates that springing/compensation should, in theory, improve road holding but that it doesn't alway work in practise.

 

After mentioning that the rigid loco runs better in an article, I got called "the worst luddite since Tony Wright" by no less than Iain Rice.

 

I was quite proud of that!

It sounds like the curves are wrong rather than the locos. The real things were limited to what radius they could go around.

 

Surely if the locos weigh the same they will have the same amount on each axle.

[James]

Surely if the locos weigh the same they will have the same amount on each axle.

 

Not at all - springing allows weight to move between different points (compensation is different). The easiest way to imagine this is to think of yourself in a powerful car. Accellerate quick and the nose will lift - in a FWD car the wheels may loose traction and in a RWD car the steering may feel light as there is less weight over the front wheels.

[davidw]

I found the comments about radius interesting. I replaced my original garage layout with a layout in a purpose built shed. The radius of track in my garage layout had a a section of track in a tunnel comprised of 2nd radius track. In my new layout in the shed the minimum radious 28 inches - still tight, and unfortunately visible.

 

I got into loco building like others due to the activity media DVD's. I wasn't interested in tank engines but big ECML power.

Contrary to advice ( start with a Tank loco etc.... ).My first build was a DJH A2. With little modification it went through that 2nd radius section of track without problem - I repeated this with DJH's A2/3.

 

With another companies kit product no way could I make the ajdustments necessary to enable it to go around that section of track. Probably with more experience I'd have come off far better.

 

For me what let's me down is not the construction but the painting lining of the finished item. This to me is what puts me off, allied with the cost

[coachmann]

An etching firm once phoned me saying an item would dissapear from the sheet because it was below line width for the thickness of material. I thanked them and told them to proceed as I would accept responsibility. Guess what, it came out just as I wanted it so blowing away accepted theory! On a similar tack, I wonder if it is the case that folk going into P4 read that springing is essential.

 

I'm tempted to dabble in P4 after seeing how good 00 track can look when neatly laid and ballasted but it would be a dead end shunt seeing as it could not be used in the garden.

[billbedford]

We habe 3 kit built 0-8-0 tender locos, which run on my Tickhill layout. This is in EM and has 3' radius curves. 2 are sprung and the third is rigid. With such a long loco on tight curves, the flange of the leading wheel runs pretty much against the outside rail. The face of the flange is at an angle, so pushing it against a rail makes it tend to rise upwards. In such circumstances, the rigid one stays on the track better. The whole weight of the loco has to be lifted up and over the rail if it is to derail. For the sprung locos, only a proportion of the loco weight is carried on each wheel. So if the wheel tries to ride up and go over the rail, it has a smaller weight holding it down.

 

The answer is either to make the frames narrower, so that there is more side play on the axles. Or more prototypically use check rails on the problem curves.

 

Looking up the allowed curve radius for LMS locos I find for most tender the minimum is 6 chains or 4.5 chains dead slow. This equates to about 5ft 2in or 3ft 11in. 3ft radius curve would be about three and a half chains at full size.

[halfwit]

I suspect one of the major reasons why British HO failed in the early 1930s is that they had not come up with the idea of compensation , and therefore a dead-scale gauge with deadscale wheels couldn't be made to work reliably .

 

'The plain fact was simple - and I have had this from two individuals who worked in 3.5mm scale - it is extremely difficult to make an accurate model of many British steam locomotives in HO. Two factors cause this, the first the size of the prototype, the second the existence, in Britain, of the raised platform. It is worth, in this connection, comparing the clearences between driving wheels and motion in British OO and Continental HO gauge steam locomotives. In general, there is fractionally more room on the Continental model.

As a result, most British modellers in the 1930s opted for 4mm scale... The choice was freely made, by the modellers of the time.'

 

C.J. Freezer, from 'All About Model Railways', a Model Railways extra magazine from 1983.

[Joseph_Pestell]

Surely the future of any loco kit must be one with chassis that runs well and can be built wobbly or rigid and in any of the popular gauges. It doesn't matter what material the body is made from or how accurate a model it is if it don't work it is rubbish.

 

Clive

 

PS Never mind if the box looks expensive you will still impress your mates when they visit even if the loco is not made.

 

To design a chassis which can be built either way sounds, to me, like a compromise which could easily lead to neither version being optimised. To go back to me earlier question, is it not better for a kit designer to offer both (but as separate kits)?

 

Still leaves, of course, the problems relating to the bodywork - normally clearance on splashers and (in a few cases) wrong wheelbase to accommodate over-sized flanges.

[Will L]

We have 3 kit built 0-8-0 tender locos, which run on my Tickhill layout. This is in EM and has 3' radius curves. 2 are sprung and the third is rigid. With such a long loco on tight curves, the flange of the leading wheel runs pretty much against the outside rail. The face of the flange is at an angle, so pushing it against a rail makes it tend to rise upwards. In such circumstances, the rigid one stays on the track better. The whole weight of the loco has to be lifted up and over the rail if it is to derail. For the sprung locos, only a proportion of the loco weight is carried on each wheel. So if the wheel tries to ride up and go over the rail, it has a smaller weight holding it down.

 

Your loco's ability to go round corners will be fare more dependant on the length of the wheelbase and the amount of available side play on the various axles than the suspension system. Where the track is in good order, if a loco won't go round a bend with just its proper share of the weight then what you need to do is look at how much side play you've got and where it is.

 

It doesn't prove anything...

 

Agree that

 

...but it illustrates that springing/compensation should, in theory, improve road holding but that it doesn't always work in practise.

 

No it doesn't, all It illustrates is that the rigid loco is capable of going round tighter curves than the other two which may have nothing to do with the suspension.

 

An etching firm once phoned me saying an item would dissapear from the sheet because it was below line width for the thickness of material. I thanked them and told them to proceed as I would accept responsibility. Guess what, it came out just as I wanted it so blowing away accepted theory! On a similar tack, I wonder if it is the case that folk going into P4 read that springing is essential.

 

Nothing says springing is essential for P4. The balanced view is that you either need some sort of suspension, or be very good at laying flat track.

[James]

To design a chassis which can be built either way sounds, to me, like a compromise which could easily lead to neither version being optimised.

 

It's easy - providing the rigid positions are there with ethed guides around them that's rigid optimised. If the tabs arpund these are kept to the minimum required to maintain structural integrety then removing them is noe more difficult than any other etched component. Compensation parts can then be provided - there is skill required to fit beams without soldering it all up solid however.

 

And this we must remember - loco building requires skill, end of. Aquring the necessary skills may take time but careful work, research and practice will see results ultimately.

[Will L]

Is there a future for Loco Kit Building?

 

While two or more of us like building locos for railways needing prototypes that the RTR makers can't see a profit in, then one of us is likely to come up with a kit and the other one will build it.

 

Will

[James]

Has anyone mentioned 009? Kit building always seem alive and well there!

[Hippo]

Has anyone mentioned 009? Kit building always seem alive and well there!

 

Yep, about 20 pages ago lol, and in the last couple of years there have been some fantastic kit's. Yes some of the old ones are dreadful, But the likes of RT models and Brian madge are showing the way forward

[James]

I can't be doing with going through that many pages again!

[Clive Mortimore]

To design a chassis which can be built either way sounds, to me, like a compromise which could easily lead to neither version being optimised. To go back to me earlier question, is it not better for a kit designer to offer both (but as separate kits)?

 

Still leaves, of course, the problems relating to the bodywork - normally clearance on splashers and (in a few cases) wrong wheelbase to accommodate over-sized flanges.

 

Hi Joseph

 

When I wrote "Surely the future of any loco kit must be one with chassis that runs well and can be built wobbly or rigid and in any of the popular gauges" I was not being prescriptive as a single chassis engineered so it could be made either way, it could be two etches in the kit or as you suggest the modeller has a choice of which type of chassis he or she requires. How the manufacturer delivers this is their choice.

 

Etched splashers and finer wheels should reduce the other problems you have mentioned.

 

Anyhow I would like to propose a summary of for the future of kit building.

 

There will always be kit builders, some for fun, and some because it is the only way they will get that locomotive. There may be an increase in this number if the price and the availability of RTR becomes a problem.

 

To entice modellers to make kits they need to be of types people wish to model and in scale and guages that people model in.

 

The kit needs a working chassis that is not too complicated to build.

 

The body needs to represent what is meant to be a model of. The parts of the body and chassis need to go together well irrespective of the material they are made of and by appropriate means of fixing them together. Motors, gears and wheels need to be readily available.

 

The instructions should be clear and concise. With today’s ease of digital cameras and home printers a step by step photo guide would I am sure help many modellers.

 

I think the above applies to all scales.

 

As a hint as to what would sell, what about a Class 11 diesel shunter? In 4mm scale and 00 guage. I would like one and so would my mate. And please can it come in an expensive looking box, SWMBO is more impressed if it comes in a nice box than if it is in a plastic bag.

[N15class]

Hi Joseph

 

When I wrote "Surely the future of any loco kit must be one with chassis that runs well and can be built wobbly or rigid and in any of the popular gauges" I was not being prescriptive as a single chassis engineered so it could be made either way, it could be two etches in the kit or as you suggest the modeller has a choice of which type of chassis he or she requires. How the manufacturer delivers this is their choice.

 

Etched splashers and finer wheels should reduce the other problems you have mentioned.

 

Anyhow I would like to propose a summary of for the future of kit building.

 

There will always be kit builders, some for fun, and some because it is the only way they will get that locomotive. There may be an increase in this number if the price and the availability of RTR becomes a problem.

 

To entice modellers to make kits they need to be of types people wish to model and in scale and guages that people model in.

 

The kit needs a working chassis that is not too complicated to build.

 

The body needs to represent what is meant to be a model of. The parts of the body and chassis need to go together well irrespective of the material they are made of and by appropriate means of fixing them together. Motors, gears and wheels need to be readily available.

 

The instructions should be clear and concise. With today’s ease of digital cameras and home printers a step by step photo guide would I am sure help many modellers.

 

I think the above applies to all scales.

 

As a hint as to what would sell, what about a Class 11 diesel shunter? In 4mm scale and 00 guage. I would like one and so would my mate. And please can it come in an expensive looking box, SWMBO is more impressed if it comes in a nice box than if it is in a plastic bag.

 

The biggest problem with a chassis is not whether there are cut outs for hornblocks etc. but it is all the castings for sandboxes, etc, and the cyilinders and motion brackets all need adapting for the three gauges. These casting would need two or three masters, and the added complication of packing to order or the customer paying for a lot of things that they do not want.

[Clive Mortimore]

The biggest problem with a chassis is not whether there are cut outs for hornblocks etc. but it is all the castings for sandboxes, etc, and the cyilinders and motion brackets all need adapting for the three gauges. These casting would need two or three masters, and the added complication of packing to order or the customer paying for a lot of things that they do not want.

 

Peter

 

You are just over complicating things. For 00 or EM the cylinders, sandboxes and motion brackets should be in the same place as they would for P4. The things a 00 or EM modeller needs to do is bend the sand pipes so they line up with the wheels and either bush out the crank pin the conecting rod is on or put a slight bend in the connecting rod. The last solution will mean a small shift in position of the piston rod and may be a little less in and out motion but not enough to worry about if the modeller can get the chassis working. 00 modellers are very use to compromise.

 

Anyhow that would not be a problem for a diesel locomotive or an inside cylinder steam locomotive.

[N15class]

Peter

 

You are just over complicating things. For 00 or EM the cylinders, sandboxes and motion brackets should be in the same place as they would for P4. The things a 00 or EM modeller needs to do is bend the sand pipes so they line up with the wheels and either bush out the crank pin the conecting rod is on or put a slight bend in the connecting rod. The last solution will mean a small shift in position of the piston rod and may be a little less in and out motion but not enough to worry about if the modeller can get the chassis working. 00 modellers are very use to compromise.

 

Anyhow that would not be a problem for a diesel locomotive or an inside cylinder steam locomotive.

It is not over complicating things, a pair of etche

Peter

 

You are just over complicating things. For 00 or EM the cylinders, sandboxes and motion brackets should be in the same place as they would for P4. The things a 00 or EM modeller needs to do is bend the sand pipes so they line up with the wheels and either bush out the crank pin the conecting rod is on or put a slight bend in the connecting rod. The last solution will mean a small shift in position of the piston rod and may be a little less in and out motion but not enough to worry about if the modeller can get the chassis working. 00 modellers are very use to compromise.

 

Anyhow that would not be a problem for a diesel locomotive or an inside cylinder steam locomotive.

 

It is not over complicating things, a set of etched cylinders will need 3 sets of slots to accomadate the 3 chassis widths. If you use the sand boxes designed for P4 on oo they will dissapear out of site under the footplate. This goes for all things mount to the outside of the chassis. Then the footplate and splashers need to be altered or your oo wheels will be in open air. It is not just a question of bending sand pipes. What would you do with things like the mounting brackets on the brake gear? you use the P4 ones the brakes would be on the flanges in oo. Then of coarse there are locos where the wheels in OO have to be further apart because of the flanges.

 

So we are all to be limited to inside cylinder locos and square boxes.

 

As for making models there are compromises in all scales and gauges, just some are greater than others.

 

There is no simple way to make one kit do everything wanted without charging a fortune for it. I feel the best policy is to make the kit as close to the real thing as possible then let everyone who wants something different adapt it.