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Discussion Starter · #1 ·
From the diecast/injection moulded thread:
Putting motors in the (steam) loco has not been the boon that central drive has been to D&E. I sometime wonder (without wishing to start an argument) that the thing wrong with tender drive was not tender drive but what was done with it. (But that's another topic anyway.)

I would be interested in reactions to this one, specifically with reference to UK models. My comments are confined to the OO and HO sphere as that's what I own and run.

Personally, drive on the prototype's driven wheels is the way to go. Five reasons: see the wheelslip so characteristic of steam; the eye is offended by the mighty tender shoving the loco along (especially when the driving wheels are locked up); UK prototype tenders frequently need major visual compromises to accept a drive; the small size and thus low weight of many UK tenders makes traction tyres necessary; and finally, tank engines have to be loco drive, so standardise on this and learn to do it really well.

Of the first two, the illusion of reality is fostered just that little bit better when the drive is in the right place. The sight of a tender moving forward even a fraction of a millimetre with the loco at rest, is simply laughable as an effect. And that's before the sight of a loco skidding majestically along, valve gear locked up: a problem by no means confined to UK OO product.

Clearly it is possible to make a good quality tender drive, with a can motor and quiet gearing, but such a product has not to my knowledge been offered in RTR UK OO. But the small size of many UK tenders, and the typical openings in the underframes, mean that there is always likely to be some visual compromise: intrusion where there should be clear sight underneath, and inability to have a modelled coal space being the usual effects. The only tender types that are likely to be able to made free from such defects are the large ex-LNE and Southern eight wheel types: pretty restrictive for UK modelling!

Then there is the traction problem, consequent on the small size of so many UK tenders, which brings in the traction tyre. Clearly these are a matter of taste. Only suitable for those modelling the Paris Metro in my opinion. They are always a source of track dirt, as I usually discover after a tender drive has visited my layout, no matter how exalted the manufacturer of the (HO) product!

Finally, since tank engines are very common in UK practise and must have loco drive, it makes sense to learn to do this well. Motors and gearboxes are now available to route drive out of sight even on small prototypes. Make the model heavy and traction is not a problem, and will be somewhat proportional to the size and thus likely capacity of the prototype machine.
 

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For a start i think we could all agree that the tender drives on uk models are just utter crap. i hold the magazines directly responsible for not saying so and i think we would have had much better models much earlier if the likes of railway modeller and model railway constructor had had the guts to say so. this was a major contributor to me going over to US modelling for nearly 10 years. i only came back after standards had drastically improved.

That said there are some very good tender drives on the continent. my BR01 has just such a mech. it drives on 2 axles of the tender and also a cardan shaft rush through the cab and drives the driving wheels in the time honoured fasion. as far as i can see this has 2 drawbacks for me. firstly the "fraction of a millimeter" of movement you alude to in your post above when the tender is moveing but the loco is not, i do find noticible. you can only see it when the loco is running at very low speeds but the very fact that i know its there somehow makes me notice it more.

Secondly there is a great big cardan shaft running between the 2. i dont care what the continental boys say, this is ugly. on a more positive note it does show off that i can make the motor just tick over. because they can watch the shaft gradually go round.

There is a huge plus with tender drives and thats traction. my roco BR01 can pull an O gauge train quite happily!

I personally dont mind decent traction tyres. i do mind the very poor ones we were palmed off with for years from the likes of hornby and lima. the ones on my hornby class 50 and the roco are discrete, they dont noticibly effect pickups and they certainatly improve traction.

Peter
 

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QUOTE Putting motors in the (steam) loco has not been the boon that central drive has been to D&E. I sometime wonder (without wishing to start an argument) that the thing wrong with tender drive was not tender drive but what was done with it. (But that's another topic anyway.)

It much easier to use flywheels and put weight in a D & E model.

UK tender drive locos have traction tyres. UK loco drive locos broadly do not although some UK tank locomotives do.

Is it more of a traction tyre issue in that for some reason UK manufacturers have an adversion to using traction tyres and their overseas counterparts do not.

HO loco models do have much smaller drive wheels than UK OO loco models. Axle height is therefore higher relative to track on UK OO models. Traction tyres can cause wobble and this will be exagerated as a result on UK OO models. It is much easier to fit a traction tyre evenly to a small wheel than a large so the argument that its down to traction tyre rubber quality does not stack up. It is down to how well the tyre is fitted and this becomes harder to do properly as wheels become larger. Therefore I can understand the adversion to the use of traction tyres however if we want the massive pulling power that some of us demand then there is no other choice but to use traction tyres in order to keep model prices down and pulling power up.

I say this because the alternative is to use diecast bodies which will increase costs and prices significantly. Even so continental manufacturers still use traction tyres!

Happy modelling
Gary
 

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In my USA modelling days. one of my favourite steam locos was the Proto Heritage 0-6-0 tender loco which was almost the same size as a traditional UK loco such as a J39.
Plastic body with first class detail, all wheel pickup including tender, loco drive & no traction tyres & it could easily pull 20+box cars (which equates to 40 four wheelers).
 

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QUOTE (Gary @ 12 Nov 2007, 18:37) <{POST_SNAPBACK}>Therefore I can understand the adversion to the use of traction tyres however if we want the massive pulling power that some of us demand then there is no other choice but to use traction tyres in order to keep model prices down and pulling power up.

I say this because the alternative is to use diecast bodies which will increase costs and prices significantly. Even so continental manufacturers still use traction tyres!

Happy modelling
Gary

*** my brassmasters locos have a resin body and pull as much as the prototype. my other kitbuilts in brass do the same. my DJH types also pull well. There we have plastic, brass and metal bodies. My friends have tender drives with motor in the tender and a fine (20 thou) piano wire to the gearbox in the loco.

NO NEED for traction tyres ever. I have no problem with them on other peoples layouts if they like them, but they'll never put a wheel on mine!!

the trick is balance of effort properly distributed. some form of suspension on the driving wheels....plus weight properly distributed. US and some other plastic steam type models often have some form of simple springing on the drivers, never have tyres and universally pull large trains.

exceptions - the classic is the huge Eureka Garrett won't pull the skin off a rice pudding - badly designed chassis and linking of the "Garrett" parts is the cause. A shame - its a lovely accurate model otherwise.

Many UK models have matured everywhere very well and now run reasonably well with nice body detail... matured everywhere that is with the exception of chassis design. Hornby simply need to look at the balance of the chassis. I suspect they look at the average train buyer and think "4 coaches in a train is average, so thats enough power!

they need to fix it!!

Pony trucks with more than a wimpy link - make them work as they should, lead the loco properly into curves and shift balance back to the drivers properly. Make the drivers sprung OR leave enough equalising movement in the non driven axles so they can equalise properly over all track and let ALL of the wheels actually grip the track.

They need to do some research into the best metal for wheels - NS is partcularly slippery!! Personally I prefer steel!

BAN first and second radius set-track under EU law wouldn't hurt either :) :) :). tight curves add enough friction to totally knacker pulling power in an "average" loco!

my favourite - change to STEEL RAIL for all track - a loco will pull 20% more on steel track, and cleaning is far less of an issue than with NS. Use a modern alloy steel and rust will be a minor issue (NS DOES rust - its just that the rust on NA is clear - and its hard too, so is bad for pickup!)

Bring back magnadhesion - it was actually a good idea really - and now, neo magnets are very small and cheap!

Regards

Richard
 

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Discussion Starter · #7 ·
QUOTE (Richard Johnson @ 12 Nov 2007, 13:04) <{POST_SNAPBACK}>.. They need to do some research into the best metal for wheels - NS is particularly slippery!! ..
Richard, in thorough agreement; to pick up on this specific point the knowledge is surely available, many of the better US HO productions use a sintered composition for driven wheels for superior traction. Product which probably emerges from the very same Chinese factories used to make much UK RTR...
 

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QUOTE (pedromorgan @ 12 Nov 2007, 22:56) <{POST_SNAPBACK}>Athearn use cintered iron (or at least they did)

Cant say i like the idea of magnaheasion though. it was great for picking up crap and burning out motors with that track pin you had left there.

Peter

Track pins?? what track pins. I can honestly say I've never used one :) :).

Actually, I do use steel rail always and may well experiment with a couple of the midland 4-4-0's especially. I'm a bit interested to see how well it works wit hscale BS95R rail though, compared to the major heavyweight steel beams that used to pass as tri-and rail :)

Richard
 

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Ah yes Peter'

The famous "I knew there was a track pin here somewhere" syndrome. I must admit I only use them now for holding track while the glue goes off, but when I was nipper it was a very different story.

Regards
 

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Discussion Starter · #11 ·
QUOTE (Richard Johnson @ 12 Nov 2007, 14:14) <{POST_SNAPBACK}>.. I'm a bit interested to see how well it (magnetic augment to adhesion) works with scale BS95R rail though, compared to the major heavyweight steel beams that used to pass as tri-and rail ..
Oh dear, dredging up my rusty physics: relatively little effect from the cross section and more from the relative magnetic coercivity indices (?) of the steels used. Ideally you want a high coercivity like that of soft iron.
 

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In the context of "good" continental tender drives being available, it is interesting that Maerklin have gone to the trouble of developing the Sinus drive so that they can fit it into small loco boilers. Now they either plan to start converting their existing tender driven range or to produce models from the first century of railways when the tenders really weren't big enough to hide the drive.

Just a thought.

David
 

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QUOTE (dwb @ 13 Nov 2007, 05:22) <{POST_SNAPBACK}>In the context of "good" continental tender drives being available, it is interesting that Maerklin have gone to the trouble of developing the Sinus drive so that they can fit it into small loco boilers. Now they either plan to start converting their existing tender driven range or to produce models from the first century of railways when the tenders really weren't big enough to hide the drive.

Just a thought.

David
The new soft drive motor really does resolve all the space issues that required location of the motor in the tender. It will have a big impact on the models that can be made accurately now. Unfortunately it only works with DCC as it has to be synchronised with the decoder and due to the low usage of DCC in the UK it is unlikely to make its way into the UK outline market. I should be getting the BR05 003, which will be the first steam loco to have the soft drive, in the next couple of months so I will be very interested to see how it performs.

In regard to the tender motor cardan shaft, these are only used by Roco and Lilliput. They do work well but I'm not a big fan. Trix/Maerklin tend to locate the motor in the boiler.
 

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QUOTE (Richard Johnson @ 12 Nov 2007, 23:04) <{POST_SNAPBACK}>NO NEED for traction tyres ever. I have no problem with them on other peoples layouts if they like them, but they'll never put a wheel on mine!!

No Continental stuff then Richard?

On a more serious note the art of compromise is essential in a club like the one I belong to.

I'm relaxed about both traction tyres and tender drive - things like performance, number of available models, how important that particular model is to my layout etc mean far more to me! But of course each to his own.

I made the comment as I have a copy of Jouef HJ2003 141P service sheet. It shows a four axle tender with drive on three, with a can motor and flywheel. It also has traction tyres but no shaft. I'm going to buy one next year (as it's darned attractive for a euro steamer!
) I imagine a heavy chassis in the loco would be a requirement which it seems to show.
A chap named the Fat Controller on another forum took this view strongly.
 

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[quote name='ozwarrior' date='13 Nov 2007, 17:03' post='39451']
No Continental stuff then Richard?

On a more serious note the art of compromise is essential in a club like the one I belong to.

I'm relaxed about both traction tyres and tender drive - things like performance, number of available models, how important that particular model is to my layout etc mean far more to me! But of course each to his own.

I made the comment as I have a copy of Jouef HJ2003 141P service sheet. It shows a four axle tender with drive on three, with a can motor and flywheel. It also has traction tyres but no shaft. I'm going to buy one next year (as it's darned attractive for a euro steamer!
) I imagine a heavy chassis in the loco would be a requirement which it seems to show.
A chap named the Fat Controller on another forum took this view strongly.

***Well actually...... surprise surprise.

At the risk of another beating from those who take every comment as an attack on their love of EU made models (its not), I'm just starting a project to remove the driving wheels from two continental loco's and both turn the flanges down to something less obtrusive and replace the driving wheels that currently have tyres..... And si'm sorely tempted to buy one of the very tasty loco kits of German prototype I've been pouring over in a catalong lately.... with no tyres, and scale flanges :) :)

I suspect that in each case loco's will actually pull as much on my soon to be started EU layout project as they did when they had tyres, as I think the real reason for the tyres is to maintain adhesion on the steep grdients and overcome the added friction of tight curves on the average smaller layout. They are a good solution for those that need them, but simply aren't needed on a more scale oriented layout.

Tender drive BTW doesn't bother me - well done, it can be superb...

Richard
 

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QUOTE (Richard Johnson @ 13 Nov 2007, 10:38) <{POST_SNAPBACK}>I suspect that in each case loco's will actually pull as much on my soon to be started EU layout project as they did when they had tyres, as I think the real reason for the tyres is to maintain adhesion on the steep grdients and overcome the added friction of tight curves on the average smaller layout. They are a good solution for those that need them, but simply aren't needed on a more scale oriented layout.

This, I think is the main reason, as stated by Richard in a nutshell why traction tyres may be favoured in mainland Europe. Tight curves, steep gradients & helix's are common there.

All Diesel & OHE locomotives that run on St Laurent have had the traction tyred wheels replaced with ordinary ones where practical - having said that, the track is level & 6 coach passenger trains are the max.
 

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QUOTE 141P service sheet. It shows a four axle tender with drive on three, with a can motor and flywheel. It also has traction tyres but no shaft. I'm going to buy one next year (as it's darned attractive for a euro steamer!
)

Having visited the French national railway museum at Mulhouse and seen the locomotives on display there, I think most of the French steamers were attractive. The thing is though that the war did for most "native" French steam locomotives so most of those in service afterwards were built in the USA. So I was wondering which 141 it was you like so much? It could be from the US.

David
 

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QUOTE (pedromorgan @ 13 Nov 2007, 16:56) <{POST_SNAPBACK}>"I should be getting the BR05 003, which will be the first steam loco to have the soft drive, in the next couple of months "

I have a K's kit for that one tucked away. it really does deserve an award for uglyness!!

Peter
It's the rebuilt one rather than the cab forward streamlined version, which, as you say, is hideous.
 
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