S ScottW's S-Scale Workbench

[ScottW]

With a number of projects recently started I thought now would be a good time to begin posting notes on their progress.

North British Railway 4-4-0T, Class R
So to begin with here is the first progress report on a North British Railway 4-4-0T, Class R (LNER D51). The basic bogie has been made with the intention of adding the remaining detail once the bogie has been married to the main frames.



The wheels have been turned from solid steel; these being kindly done for me by Trevor Nunn of East Lynn fame. With the wheels being made of steel split axles were required to insulate the two ends of the axles from each other, with the bogie frames being electrically isolated by using a PCB frame spacer. One feature of the bogie on these 4-4-0T's was the narrow frames and external axleboxes. To try and represent this I have used Exactoscale 2mm axleboxes (designed for 4mm scale) soldered onto the outside of the bogie frames.

Regards,

Scott

 

[Dog Star]

Very nice, thank you.

 

[JimG]

So to begin with here is the first progress report on a North British Railway 4-4-0T, Class R (LNER D51).

You beat me to it. I have a set of the brass wheel castings in front of me at the moment to start on a Caledonian 670 class. But I've got to get the April Gazette out first. I've bored and sliced off the material for four tyres on the ML10 in the outside workshop a couple of weeks ago and I could start turning them while I'm cutting stuff on the mill - the Cowells and the mill are side by side on the inside workbench. One of the benefits of CNC.

Looking good on the bogie. Don't you just love Drummond's solid wheels - no spokes to cut out.
[Edit] Did you do the bogie frames on the Taylor Hobson?
Jim.

 

[ScottW]

I have a set of the brass wheel castings in front of me at the moment to start on a Caledonian 670 class.

Despite being of the blue persuasion the Caley 670 class were interesting beasties and I'm looking forward to seeing it progress. Good luck with that footplate.

Trevor turned the wheels for me a number of years ago due to me not having a wheel forming tool. It's taken all this time to make a start on the rest of the loco, although in my defence I haven't been idle. I thought I'd best make a start seeing as I'll need something to pull all those planned coaches.

Regards,

Scott

 

[ScottW]

Did you do the bogie frames on the Taylor Hobson?

I cut both the bogie frames and the PCB spacer on the Taylor Hobson. It is my intention to produce a majority of the platework for the 4-4-0T using the machine, hopefully once the loco is complete I'll have a good handle on how best to use it.

Regards,

Scott

 

[ScottW]

North British Railway 4-4-0T, Class R
The 4-4-0/0-4-4 type chassis is apparently notorious for having problems regarding balance and adhesion. Over the years there have been many ideas on how best to get over these problems; springing, compensating or just adding plenty of weight over the drivers are three methods seen used in the past. With this being my first attempt at a 4-4-0T I was indecisive whether I should compensate or spring the chassis. After much discusion with friends I have decided to spring the loco, the drivers are to be sprung using the Continuous Springy Beam (CSB) method with the bogie wheels being fitted with their own independant coil springs. It is also intended to fit a coil spring between the main frames and the bogie chassis to provide a little downward pressure on the bogie.

Having cut the frames from 18thou Nickel Silver, drilled the holes for the brake hangers and CSB fulcrum pillars they were mounted on the chassis jig, in turn, and the hornblocks soldered into position. My prefered type of hornblocks are those produced for 4mm scale by High Level Kits, these are simply folded up and soldered onto the frames. Unlike other designs of hornblock nothing is glued, nor does anyhing drop off when being soldered.



Providing the CSB fulcrum pillars are 4mm scale handrail knobs markited by Markits. Those pillars soldered onto the main frames are of the WD "short" type with the pillars on the hornblocks being of the WD "long" type. The hornblocks are temporarily fitted using 0.45mm brass wire, when it comes to setting up the chassis they will be replaced by spring steel.



Before soldering the main frames together the bottom of the firebox and ashpan detail was added. U-channel was also soldered onto both the front and back of the frames in which the PCB frame spacers will be secured. As with the bogie the driving wheels are of an all metal constuction making it necessary for the frames to be of a split frame design.



With the main frames complete they were mounted back on the chassis jig, with the frame spacers, and soldered together. Aluminium spacers were turned down and used to assit with keeping the frames parallel during construction.



Once all soldered up the chassis was removed from the jig and given a good scrub with an old toothbrush and cif cream cleaner.



The next stage will be to make up the gearbox and fit the wheels.

Regards,

Scott

 

[AdamF]

Lovely work

I can't wait to see this develop!

 

[Simon Dunkley]

with the bogie wheels being fitted with their own independant coil springs. It is also intended to fit a coil spring between the main frames and the bogie chassis to provide a little downward pressure on the bogie.

If you go for working compensation beams, lightly sprung to centralise them, with a coil spring mount to the bogie, then you will have a sliding contact between loco and bogie and fewer problems. (See Chris Pendlenton's early MRJ article, number 6. PM me if you do not have it.)

U-channel was also soldered onto both the front and back of the frames in which the PCB frame spacers will be secured.

Brilliant idea. I wish I had thought of that, or come across the idea years ago.

 

[ScottW]

If you go for working compensation beams, lightly sprung to centralise them, with a coil spring mount to the bogie, then you will have a sliding contact between loco and bogie and fewer problems. (See Chris Pendlenton's early MRJ article, number 6. PM me if you do not have it.)

I will confess that this is my second attempt at this loco. My first attempt was started a few years ago and it was my intention then to build the bogie as you described, although the idea came to me from Ted Scannell.

http://www.clag.org.uk/class2p-bill.html

Since then a few more seeds of thought had been planted and I decided to change the bogie design to one used by the late Mike Gilgannon. (See MRJ #125 for Mike's article on how he built his NBR 4-4-2T).

Brilliant idea. I wish I had thought of that, or come across the idea years ago.

The idea came to me from another MRJ article. ("Sibling Rivalry" by Geoff Tiffany, MRJ #201)

Regards,

Scott

 

[Simon Dunkley]

Hi Scott,

I will confess that this is my second attempt at this loco. My first attempt was started a few years ago and it was my intention then to build the bogie as you described, although the idea came to me from Ted Scannell.

http://www.clag.org.uk/class2p-bill.html

That's not quite what I had in mind - although there is a springy beam either side of the bogie, the beam itself appears to be rigidly mounted, rather than via a spring to the bolster, which carries the loco's weight, providing secondary springing which is really needed for a bogie, if you have "full" (up and down) springing on your drivers.

The idea came to me from another MRJ article. ("Sibling Rivalry" by Geoff Tiffany, MRJ #201)

Still more recent that any chassis builds I have undertaken!

 

[ScottW]

That's not quite what I had in mind - although there is a springy beam either side of the bogie, the beam itself appears to be rigidly mounted, rather than via a spring to the bolster, which carries the loco's weight, providing secondary springing which is really needed for a bogie, if you have "full" (up and down) springing on your drivers.

I think the photographs might be deceiving. The springy beams are actually attached to the beams allowing them to flex up and down, the axles then push up against the beams when the bogie is placed on the track. This might be a better example:

http://www.clag.org.uk/midbogie.html

The main reason for opting for the Exactoscale sprung axleboxes is due to me wanting to try and represent the outside axleboxes evident on the actual locomotive. It is my intention to fit cosmetic beams onto the Exactoscale axleboxes.



Regards,

Scott

 

[Simon Dunkley]

Ta.

Nice work.

 

[JimG]

I think the photographs might be deceiving. The springy beams are actually attached to the beams allowing them to flex up and down, the axles then push up against the beams when the bogie is placed on the track. This might be a better example:

Richard (Dikitriki) and I were wondering if those are brass rods across the bogie frames at each end, and how they avoid shorting out the insulation.

Jim.

 

[ScottW]

Richard (Dikitriki) and I were wondering if those are brass rods across the bogie frames at each end, and how they avoid shorting out the insulation.

How perceptive of you both, it is brass rod. Don't worry though the rod will be cut once the remaining detail has been soldered on, insuring the frames are electrically isolated.

Regards,

Scott

 

[JimG]

How perceptive of you both, it is brass rod. Don't worry though the rod will be cut once the remaining detail has been soldered on, insuring the frames are electrically isolated.

I thought there might be a logical reason.

Jim.

 

[ScottW]

North British Railway 4-4-0T, Class R
Sadly the workbench has been lying deserted these past few weeks due to work commitments, since my last posting I have managed to get some work done on getting the basic chassis up and running. The main components for the running chassis are brass centred wheels purchased from the S-Scale Society's stores, 1/8" split axles and a High level Kits RoadRunner+ gearbox.



A number of new ideas, picked up from other modellers, have been incorporated into the gearbox. The first of these ideas prevents the gearbox drive stretcher from rotating around the gearbox. Rather than securing the drive stretcher with solder a spring catch has been soldered onto the inside of the chassis. The end of the spring catch has been bent at 90 degrees to alow the catch to fit in a hole drilled through both the gearbox and the drive stretcher. When the end of the spring catch is pulled clear of the gearbox the drive stretcher is free to rotate, this in turn helps removal of the rear wheel set and gearbox from the chassis. In the picture below you can make out the U-shaped spring catch soldered onto the inside of the gearbox.



As the main drivers are sprung the second idea is a form of torque reaction beam which also enables the rear wheels of the locomotive, and gearbox, to move up and down. An L-shaped bracket has been soldered onto the rear of the gearbox, this in turn is supported by a 10 BA bolt and coil spring secured onto the frame spacer situated in the ash pan.



The wheels were mounted onto the 1/8" split axles and quartered using a GW Models wheel press & quartering jig. On fitting the coupling rods for the first time there was a slight bind between them and the wheels, after opening the holes in the coupling rods slightly the chassis ran freely up and down the test track. Despite being expensive, using jigs like the chassis 2 assembly jig and the GW Models wheel press certainly helped build a smooth running chassis with little trouble.



The bracket soldered onto the top of the gearbox provides a mounting position for a DCC chip. Having now installed the gearbox in the chassis this mounting position may be a bit high leaving little room between it and the underside of the boiler. A better idea of the available space will be gauged once work commences on the body.

Regards,

Scott

 

[AdamF]

Lovely clean work

 

[ScottW]

North British Railway 4-4-0T, Class R
A little progress to report with the loco as it is now sporting it's footplate. The footplate has been made from 10 thou nickel silver with the headstocks and valances being cut from 18 thou nickel silver.



Once the headstocks and valances were soldered in place the centre section was cut out to enable the footplate to sit on top of the mainframes without fouling the motor and wheels. You can see one similarity with the Brighton Terriers in that the footplate is lower than standard with the buffers protruding above the footplate. 10BA bolts at each end of the loco were used to secure the footplate to the chassis.



Regards,

Scott

 

[ScottW]

North British Railway 4-4-0T, Class R
Over the last few weeks I managed to get round to producing the sides and ends for the cab. Patterns were made from Plasticard, three times larger than that required, and the parts cut out on the profile milling machine. Before soldering the assembly the parts have been temporarily stuck together with Blue-Tack to get some sort of idea how it all looks.



Regards,

Scott

 

[JimG]

North British Railway 4-4-0T, Class R
Over the last few weeks I managed to get round to producing the sides and ends for the cab. Patterns were made from Plasticard, three times larger than that required, and the parts cut out on the profile milling machine. Before soldering the assembly the parts have been temporarily stuck together with Blue-Tack to get some sort of idea how it all looks.

I need a picture of your progress for the next Gazette - out next week with a bit of luck. I will have Barry Witham's SAR Class 25 to feature, so a bit of Victorian elegance will offset it nicely. Looking great, as usual.

Jim.