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Walschaerts Valve Gear


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Dear all,

When will Hornby and Bachmann ever get Walschaerts valve gear correctly assembled. With the weight of Railway Modeller, would it be possible to pass on my attached pdf file to the design teams at Hornby and Bachmann who boast of laser scanning the prototypes to achieve the highest degree of detail and proportion and yet when it comes to the positioning of valve gear eccentrics; the manufacturers in China seem to lack correct assembly information and invariably get it wrong; if they were real locos….they wouldn’t go!!

 

Tony Clout

 

Walschaerts Valve Gear eccentric positioning(inside admission).pdf

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I find it amusing that someone complaining about people making errors posts "With the weight of Railway Modeller" when that magazine has nothing to do with this forum. Unless you feel we should drop old copies of RM on people!

 

 

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41 minutes ago, Tony Clout said:

When will Hornby and Bachmann ever get Walschaerts valve gear correctly assembled.

 

You're probably better to ask them rather than throw questions into the wider internet; or maybe it's very niche rabble-rousing?

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43 minutes ago, Tony Clout said:

Dear all,

When will Hornby and Bachmann ever get Walschaerts valve gear correctly assembled. With the weight of Railway Modeller, would it be possible to pass on my attached pdf file to the design teams at Hornby and Bachmann who boast of laser scanning the prototypes to achieve the highest degree of detail and proportion and yet when it comes to the positioning of valve gear eccentrics; the manufacturers in China seem to lack correct assembly information and invariably get it wrong; if they were real locos….they wouldn’t go!!

 

Tony Clout

 

Walschaerts Valve Gear eccentric positioning(inside admission).pdf 397.95 kB · 9 downloads

I am sure that the people in China do have the correct information.

However it is the designers and the people that they report to who have the clout to say just what should be produced.

What did you get for Christmas?

A big wooden spoon is my guess.

Bernard

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Could you explain exactly what is wrong with RTR Walchaerts, Mr Clout.  It cannot as yet be modelled in more than one static position setting, though of course forward and reverse gear settings and cut-offs may be achievable with DCC control in the future.  If the gear was modelled in anything but mid gear position, which is presumably why you are saying that the locos 'wouldn't go', they would be just as  wrong for anything except that particular position.  Most model railway locomotives are stationary most of the time, and mid gear is probably as good a compromise as can be reasonably achieved with RTR volume produced models.  

 

It's a bit academic from my point of view, as I model 1950s South Wales WR in a mining valley; no locos have Walchaerts and even those with outside cylinders have (unmodelled) inside Stephenson valve gear.  I'm more bothered that my locos cannot produce realistic steam and smoke effects that are acceptable in a domestic environment.

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I don't understand the OP, not at all. There have been incidents where the position of the return crank has been modelled incorrectly, but the RTR manufacturers generally get it right.

I wonder if the OP has fired off his post without reviewing it first, we've all done that and later regretted it, certainly I have.

Cheers

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There was an article in a Canadian modelling magazine (probably a coule of decades ago) showing how to "correct" your locomotives by making the eccentric crank line up with the centre of the wheel.

 

 

There were some letters about it in the next issue.

 

 

Edited by BR60103
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Highly critical of the position of the eccentric presumably and yet ignores the approximate 48" gauge of the model.  Odd that everything except the gauge has to be prototypical.

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I'd like to see how someone (typically, a modeller) can be expected to demonstrate full-forward gear in 4mm scale. Then, as the locomotive gathers speed, link up, and if needed, alter the valve events for going uphill, coasting, and finally.... GASP! -Go into reverse!

 

The best you can expect is a facsimile of the true motion which will be when coasting. Luckily for us modellers, Triang were doing this back in the 50's, with the old Princess  Elizabeth. It might be more refined nowadays, but it is still essentially the same.  

 

If you have a set of working Walshearts gear in 4mm (my preferred medium), then you'll have my fullest attention.  Does it have working drain cocks & snifting valves as well? I'll bring along some eggs & bacon, and we'll have a fry-up on the shovel...

 

Have a great Sunday-Funday, folks.

 

Ian.

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Mr Clout's only managed two posts, and both of them are whinges. Is this some kind of record? Speaking for myself, I shall be writing to my

MP about the appalling state of Hornby's moulded coal.

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33 minutes ago, Barry Ten said:

Mr Clout's only managed two posts, and both of them are whinges. Is this some kind of record? Speaking for myself, I shall be writing to my

MP about the appalling state of Hornby's moulded coal.

Maybe he is posting from Norway ;)

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1 hour ago, tomparryharry said:

I'd like to see how someone (typically, a modeller) can be expected to demonstrate full-forward gear in 4mm scale. Then, as the locomotive gathers speed, link up, and if needed, alter the valve events for going uphill, coasting, and finally.... GASP! -Go into reverse!


 

I assume we will see this in the coming years. Märklin announced a French locomotive in 1 Gauge which mentions in the spec: 

Valve gear switchover (forward, reverse, continuous operation) in 3 steps with a servomotor.

 

A 0 gauge manufacturer will follow on this and then H0/00. Just wait.

Regards

Fred

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2 hours ago, tomparryharry said:

I'd like to see how someone (typically, a modeller) can be expected to demonstrate full-forward gear in 4mm scale. Then, as the locomotive gathers speed, link up, and if needed, alter the valve events for going uphill, coasting, and finally.... GASP! -Go into reverse!

 

The best you can expect is a facsimile of the true motion which will be when coasting. Luckily for us modellers, Triang were doing this back in the 50's, with the old Princess  Elizabeth. It might be more refined nowadays, but it is still essentially the same.  

 

If you have a set of working Walshearts gear in 4mm (my preferred medium), then you'll have my fullest attention.  Does it have working drain cocks & snifting valves as well? I'll bring along some eggs & bacon, and we'll have a fry-up on the shovel...

 

Have a great Sunday-Funday, folks.

 

Ian.

 

There's a 2mm 9f on here somewhere that has a forward and reverse gear selectable by DCC. Amazing little gadget. 

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2 hours ago, Mr chapman said:

 

There's a 2mm 9f on here somewhere that has a forward and reverse gear selectable by DCC. Amazing little gadget. 

 

And there's probably someone out there that would take that seriously!!:sungum:

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I

2 minutes ago, bike2steam said:

 

And there's probably someone out there that would take that seriously!!:sungum:

There is a T-scale Hunslet Austerity with a lot of working parts.

 

very good for 'tea' scale, if you ask me......

 

With due deference & best wishes to modellers whom model at that scale.

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The closest to working valve gear in recent times was Bachmann's K3 but this really affected smooth running and reliability. Mine personally needs constant tweeks before being put to work on a layout. Dublo and trix did quite a robust moving set but hardly to scale. Personally, keep it simple please.

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I might risk saying that for me, by and large, today's model representation in 4mm scale of Walschaerts valve gear does a pretty good job visually.

 

Never ever the pedant, however, following this topic I couldn't resist double checking my rebuilt Bullieds, and was pleased to find the return cranks set correct for outside admission valves. 

Phew! I can sleep soundly now; just hope China have allowed for lead steam!

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I have to confess that I do try to adjust my Hornybee Bulleid (modified) Pacifics' gear to have a reasonable looking return crank position as per the prototype [as you all know, as Right Away has just said whilst I was posting] is set differently for the admission valves set up), however it isn't top of my list of things to do as  my bloomin' layout is nowhere near finished. 

Edited by Mallard60022
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