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A new 'Old Engine' - GWR 184 - part 4


MikeOxon

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Part 4 already, and I've not actually touched any metal yet! My thanks to all who have given encouragement by their 'Likes' and a warning not to expect any 'model engineering' in this thread - it's more like cut-out scrap-booking - but I enjoy it and it might lead to a working model.

 

Since my last post, I've re-visited the cab area, so that it can accommodate the rear pair of drivers. On my paper model, I've cut slots in the front of the cab and floor, to allow for the 14.4mm back-to-back separation of 00-gauge wheels. It seems reasonably firm and I can build up the wheel-boxes inside the cab, in the final model.

 

184-papercab.jpg.f7f5c5c52fc012b7d40cce23d1ddfb87.jpg

 

 

The following early view of the footplate of a Dean 2-4-0 shows the 'look' that I wish to achieve, with its very simple backplate.

 

Deancab.jpg.6b0f9968504472889b9199fb7da19fce.jpg

 

 

A more tricky problem is posed by the boiler. It was easy enough to roll a tube of paper to the correct dimensions. After a few trials, I decided to make the tube extend the entire length from the front of the smokebox to the cab. Photographs of the real engine indicate that, although the top of the firebox casing is raised, the sides are flush with the boiler cladding, so I could add the firebox as a 'wrapper', fixed to the sides of the boiler. I'll leave the problem of creating the shaped fillet needed between the firebox and the top of the boiler for later. The immediate problems begin, when trying to fit the boiler assembly between the wheels.

 

184paperboiler.jpg.5a5370642272fab34b77a018ca9094b1.jpg

 

 

As I discovered when building my 'Queen' model, the real boiler diameter scales to something larger than the 00-gauge back-to-back dimension, so some cut-outs are essential. This proposed model raises the additional problem of how to accommodate a motor and drive unit. For this, I turned to the 'High Level' website , from where you can download a very useful 'Planning Sheet', with scale drawings of motors and gearboxes.

 

By copying the relevant drawings and pasting them over my own scale drawings of the engine, It appears that I should be able to accommodate a 'RoadRunner' gearbox with 'Mashima 1220' motor, within the profile of my model. I've also indicated how it should fit within my paper template

 

184motorposn.jpg.00a486ce35861a79d20aa63ead60c3de.jpg

 

 

My plan is to cut away the underside of the boiler, where it will be hidden behind the wheelarches and firebox sides, sufficiently to allow the superstructure to be lowered over the motorised chassis. I have not scratch-built a working chassis before, so intend to keep it as simple as possible. I shall use my kit-built model of a Hudswell-Clarke 0-4-0 (TVR 'S'-class) as a basis for the design.

 

0-4-0chassis.jpg.060c033e1a434cd472cc32020c5fd6ef.jpg

 

 

The kit chassis consists of two brass strips, separated by Markits-type spacers. Providing that I can manage to drill the holes in the right places, it does not look too difficult, though when I look at Snitzl Works amazing Wheel Quartering Jigs , I wonder if I might be fooling myself.

 

I feel that I had better turn my attention to trying to build a working 0-4-0 chassis, before I do any more on superstructure design :)

 

Mike

 

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Edited by MikeOxon
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Pretty quick progress so far, a few weeks ago you didn't even have a descent drawing!

 

It's interesting to see the challenges you encounter with the gauge, we are so quick to dismiss the compromises made on RTR locos, yet this must be exactly the challenges encountered by RTR designers - although I suppose it's especially tricky with these smallish early engines and roundtopped fireboxes. 

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Hi Mikkel - yes, quick progress so far but this was the easy bit!  I may pause for a while, to build up courage for tackling the chassis!  Perhaps a little gentle scenery work around North Leigh, and I must catch up with the Wilcotes again.  Blanche really does need her new dresses.

 

I agree that the RTR designers face huge challenges that can only be appreciated when trying to build things oneself.  It's not just a matter of making things fit but also trying to mask the visual errors.  I think RTR users might be more forgiving of the odd 0.5mm dimensional errors, if they understood what is involved.  Some people enjoy the challenge of making trains run with minute flanges, etc. but I am prepared to accept some compromises, in return for a quiet life.

 

As you know, my layout is based on old Hornby-Dublo track, with 15" radius curves yet, somehow, they made A4s and Duchesses go round these with aplomb.  Admittedly, the sight of a front bogie seemingly almost at right-angles to the body was a little unrealistic :)

 

Mike

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Thanks, Alan.  In fact, I've had a bit of an overall 'pause' because other jobs around the house have been needing attention! 

 

I do find that pauses are important when scratch-building as, often, new ways of doing things spring to mind.

 

Mike

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