CSBs and the Single Bogie

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Will L
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Re: CSBs and the Single Bogie

Postby Will L » Tue May 24, 2011 11:59 am

Craig commented at an early stage of this thread and some time ago

craig_whilding wrote:Two methods I can think of -

1 - You count the bearer the bogie is pushing against as an axlebox and attach it to the CSB and provide it with hornguides.

2 - You tap a tube for a screw in one end and a coil spring in the other and allow the height of the bogie to be adjusted finely by the screw but this is still effectively independent of the CSB. The pivot would need to be a tube on the bogie outside of the body tube with the spring in.


Spot on I should have said, but I didn't want to comment at the time as to do so would have been to give away the plot of what was to follow! So now you can see I considered both of these approaches but ended up doing something different.

Will

ScottW
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Re: CSBs and the Single Bogie

Postby ScottW » Tue Mar 13, 2012 6:34 pm

Will L wrote:Again start with a S4CSB and separate sprung bogie. Set the CofG to be 1/3 of the way from the centre of the driving axles to the bogie pin and the bogie will carry 1/3 of the loco weight. You can choose some other weight distribution if you wish. I will post more details on how to work it out, but later.


I'm just about to embark on building a 4-4-0T. I have decided to fit CSB and found your article both interesting and helpful, is there any chance you could expand on how you worked out the CSB plot for the shift in CofG.

Regards,

Scott

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Will L
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Re: CSBs and the Single Bogie

Postby Will L » Tue Mar 13, 2012 9:23 pm

ScottW wrote:I'm just about to embark on building a 4-4-0T. I have decided to fit CSB and found your article both interesting and helpful, is there any chance you could expand on how you worked out the CSB plot for the shift in CofG.


Hi Scott, good luck fitting your 4-4-0 with CSB.

The additional information, signed posted at the end of this thread about setting up CSB chassis with some weight on a bogie, actually turned up the CSBs a question of Gravity thread. It may not be immediately apparent at the beginning but it does get there. So have a read and then if you've got questions I'll be very happy to help.

Will

ScottW
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Re: CSBs and the Single Bogie

Postby ScottW » Wed Mar 14, 2012 5:24 pm

Will L wrote:Hi Scott, good luck fitting your 4-4-0 with CSB.


Thanks Will.

Having read the article and revisited this one I relise I had picked up the wrong end of the stick. Originally I understood that you had altered the position of the fulcrum points of the CSB chassis to alter the C of G, quite simply you have altered the weight the loco. Doh!!!

Harking back to my apprenticeship days "read the f**kin question!!"

Regards,

Scott

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Chas Levin
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Re: CSBs and the Single Bogie

Postby Chas Levin » Sun Jan 31, 2021 8:26 pm

Will L wrote:Getting it to Run.

The Gibson driving wheels have been quartered using the CW jig, as always. The gearbox is a standard Highlevel Loadhauler which, because the design of horn blocks used by the kit maximises the space available, just fits between the frames. Washers eliminated all the side play on the drivers. Only a modicum of opening out of crank pin holes in the rods was necessary and the chassis was soon bind free and turning over sweetly. All in all a nice bit of chassis design.

My only other mod was the up stand I used to attach the torque reaction link, the other end of which went through a hole drilled in the side frame of the gearbox. Bill does provide bits for this but no guidance as to how they fit. I’d gone my own way before understanding dawned.

Balancing the assembled chassis and loco

From the posts further back up the thread, you should have gathered that, as the bogie is separately sprung from the driving wheels, the available options for balancing the chassis resolve around placing the CofG some way forward of the classic “central over the CSB” position. Because the CSB on the driving wheels is a symmetrical 4 wheel arrangement, if the chassis sits level then the weight carried by all the driving wheels will be equal, which is just what we want. So the trick is to get the chassis sitting level. My available choices were either, to set the Loco CofG a fixed amount forward and juggle with the height at which the bogie supports the chassis, or, to adjust the position of the CofG of the loco. In either case you're done when the chassis sits level. Given the bogie modifications involved in fitting the pick ups, only the "adjusting the CofG" position option was really available to me.

For the sake of argument, I did a trial with the body weighted to put the CofG central over the driving wheels. In this state, the results were as you should have expected. The loco was visibly sitting high at the front. The pulling power was very limited, three relatively light bogie coaches had the wheels slipping on the flat, and it was inclined to derail at the slightest excuse.

Measuring buffer heights confirmed that the front of the loco was sitting markedly higher than the back, by more than 1mm at the top edge of the buffer face. So lead was added into the front of the boiler and between the frames over the bogie, until the buffer height was the same front and back. These measurements were not particularly precise, and the possible error could be a few 1/10s of a millimetre, but despite this, the haulage power and road holding were transformed. Now five much heavier coaches could be pulled up an incline with no problem. I’m still waiting to get access to a larger layout to find how big the load has to be before she starts struggling.

And that was it. Off she went to the paint shop, and when last seen she was earning her keep on Knutsford with no issues. All she needs now is lamps and a new layer of coal on the bunker!
CSB C12 veiw 1.jpg
And Finally

Here ends my planned posts to this thread, although I’m happy to discuss what I’ve done further with anybody who wants to. I hope this has sorted out the options for doing CSB’s on 4-4-0 loco’s and got it to the point where anybody else who wants to have a go can try it and be confidence of success.

One final word, I plan a post or two on the theory, when we might stretch a point and think about 4-6-0s too. I know a lot of you find the theoretical stuff more off putting than helpful, so they will turn up on another thread. After that it will be back to the J10 which requires a lot of non CSB related work.


Hello Will, having carefully bookmarked this topic for future CSB reading, I realised it might also help with a far smaller point I'm currently unsure about. I'm building an LRM C12 and amongst the included detailing are spark shields. They're even shown on the Isinglass drawing but it isn't quite clear exactly where they sit in relation to the cab window and its beading.

You show a couple of pictures of that excellent looking C12 early on in the thread, including what look to me like the very spark shields I've been agonisng over, but because the photos are quite low resolution I can't tell for sure, even by zooming in (no criticism intended, they look absolutely fine for normal viewing and I know I'm asking a lot to examine such small details in close-up!).

I realise you posted the pictures a decade ago (times flies...) but I wondered whether by any chance you still have access to the loco and if so, could you please post a close-up picture of the shields? Or did you might perhaps keep high resolution versions of the pictures you took at the time?

I've already collected several dozen C12 pictures from the famous Interweb but aside from those two of yours, I've found no others so far that show this small but interesting detail. Neither have I so far turned up anything in my own library, though every time I start going through another book, I get distracted by all the other lovely photos... :)

Thank you in advance,

Chas
Chas

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Will L
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Re: CSBs and the Single Bogie

Postby Will L » Mon Feb 01, 2021 12:06 am

Chas Levin wrote: I'm building an LRM C12 and amongst the included detailing are spark shields. They're even shown on the Isinglass drawing but it isn't quite clear exactly where they sit in relation to the cab window and its beading.

You show a couple of pictures of that excellent looking C12 early on in the thread, including what look to me like the very spark shields I've been agonisng over, but because the photos are quite low resolution I can't tell for sure, even by zooming in (no criticism intended, they look absolutely fine for normal viewing and I know I'm asking a lot to examine such small details in close-up!).


My C12 is actuality a Craftsman kit and was one of the first etched brass kits I ever did. It did about 10 years on our OO layout in the eighties. When I joined in with the Crewe Area Group we were looking for appropriate locos for Knutsford East (i.e. the Cheshire Lines) just post WW2. A C12 fitted the bill and we had photos of an appropriate loco. My old C12 was always a descent looking loco so it got an update with a new P4 CSB chassis (a la Bill Bedford) and some added details. Yeadon's Register of LNER Locomotives volume 33 covers the C12s and will show you what you need to know.

As it happens I did take a photo of the my C12 with the added detail before the repaint, mostly to show of the added fire iron and coal hammer detail which I was amused by at the time. It also shows the spark shields which look like they were party of the original kit although the shiny edges suggests they got some attention at the time. At this distance in time I don't remember. It also shows that my interest in the plumbing isn't that new. Hope this helps. This is a full resolution photo so you can explore the detail.
P1010555.JPG
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Chas Levin
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Re: CSBs and the Single Bogie

Postby Chas Levin » Mon Feb 01, 2021 12:32 pm

Good morning Will, thank you so much for the reply and for the picture: I could not have imagined a more perfect answer! How very lucky for me that you happened to take this photo - it shows those details even more clearly than a hi-resolution copy of the fully finished loco would have done.

I had of course noticed the fire irons and the coal hammer which amused me too :) . I might take a leaf from your book on those - if so, I hope it will appear as a tribute rather than plain old copying... ;)

I don't yet have any Yeadons volumes, though they've been on my list for a while. For this build I got the Isinglass drawing which has provided a great deal of information, both pictorially and from the copious notes about particular modifications, but the only view showing the spark shields is from the rear looking forward, 'through' the loco and what with all the other details shown, it isn't exactly clear on them - not the fault of Isinglass of course: no-one would reasonably expect such a tiny detail to recevie special attention.

As to the plumbing - another detail of your model that for me makes it stand out - I am contemplating that too...
Chas

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Will L
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Re: CSBs and the Single Bogie

Postby Will L » Mon Feb 01, 2021 2:59 pm

Chas Levin wrote:I had of course noticed the fire irons and the coal hammer which amused me too :) . I might take a leaf from your book on those - if so, I hope it will appear as a tribute rather than plain old copying... ;)
Thank you for appreciating my response. Makes it all worth while. We are all copy-ists aren't we? But we are not coying we are sharing. Finding inspiration in what other achieve is perfectly valid way forward, the trick is finding ways to improve on what your copy!

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Chas Levin
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Re: CSBs and the Single Bogie

Postby Chas Levin » Mon Feb 01, 2021 8:50 pm

My pleasure Will; it's only polite to thank someone when they've gone to some trouble. I always hesitate to ask these sorts of things in case it involves a lot of laborious digging around and I had looked at a lot of pictures - online and in books - before asking you, but those shields appear to be a very rarely modelled detail.
And yes, I agree that to improve on something you see in someone else's work is perfectly fine. My backgournd is in music, where composers and performers have been doing just that since a monk in one monastery lifted a phrase of plainsong he'd heard at the place up the road :D .
Chas

down_under
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Re: CSBs and the Single Bogie

Postby down_under » Tue Nov 28, 2023 7:21 am

Question for Bill Bedford:

Would it be possible to do a re-run of the C12 etched chassis kit? If so how many orders do you need to make it worth while?

Cheers,

James


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