DJH Kit BR Standard Class 4 Mogul to EM/P4?

[PenrithBeacon]

7 hours ago, Captain Kernow said:

As you may have noticed, I don't like CSBs either.

 

However, if installing springing (even if Comet's own design), then this indicates that all three axles will need to be sprung, including the driven axle.

 

If you want the driven axle to be fixed, then there are only really two practical alternatives, namely single beam compensation (yes, you would need to source the right size brass tube and beam, probably from Eileens Emporium, then measure and make up the single compensation beam, but if you have acquainted yourself with the principles from Iain Rice's book, then it should be pretty straight forward) or a rigid chassis.

 

Whichever route you go down, I'd recommend familiarising yourself with what Iain has written first.

 

If, however, as you have said, Amanda, that this is your first actual chassis and you're working in EM gauge (as opposed to P4), then you really don't need to compensate or spring it at all.

 

You are also building Walschaerts valve gear, which is an added level of complication.

 

Pick up reliability can, in any case, be improved by adding pick ups to the tender, so the advantages of compensation or springing are not so apparent (as compared with a tank loco, for example).

 

So, whilst all this advice on compensation, springing etc. is all good (and I certainly do not intend to take issue with anything that anyone else has suggested), I would really, really have a long, hard think about whether you need to fit compensation or springing at all.

 

If I was in your situation, I would definitely build the chassis rigid or perhaps have a practice run at compensating or springing on a simpler 0-6-0 tank loco chassis.

 

I have a lot of sympathy for this post but the OP said he wanted to compensate/spring hence my post.

Last October I decided to build the Comet Jinty chassis and to simplify as much as possible I fixed the rear/driving axle, had the middle one independently sprung using the Comet system and the leading one rocking. It took absolutely no time at all and it works really well. Dead pleased.

Having said that I too think the OP might be better off following your advice, at least for now.

Cheers

[Guest WM183]

HI all.

 

I'll have a good think over whether or not to try to build it compensated. I don't mind building it rigid. 

[Captain Kernow]

1 hour ago, PenrithBeacon said:

Last October I decided to build the Comet Jinty chassis and to simplify as much as possible I fixed the rear/driving axle, had the middle one independently sprung using the Comet system and the leading one rocking. It took absolutely no time at all and it works really well

That's very interesting and I can see how this would work nicely - the 'three legs' of the 'stool' are the two bearings of your (rear) driven axle, plus the centre of the leading axle, rocking on it's (presumably fixed) beam? The middle wheels, being sprung, provide some additional track contact, rather like the way that Bachmann have sprung a small number of their 3 axle locos, such as the 08 diesel shunter.

 

Might try that myself sometime!

 

[PenrithBeacon]

I basically got the idea from Bachmann's method mixed up with the three legged stool idea of the MRSG (?) of all those years ago. The front rocking beam is put in before the hornblock cutouts are removed so ensuring it bears down accurately on the front axle. I've got some pictures on the desktop which I could publish, if I remember!

There's a lot of talk about pickup reliability on here, you can do away with pickups if you go to BPRC something else I've adopted with enthusiasm. Always keen to simplify!

[Guest WM183]

2 hours ago, Captain Kernow said:

That's very interesting and I can see how this would work nicely - the 'three legs' of the 'stool' are the two bearings of your (rear) driven axle, plus the centre of the leading axle, rocking on it's (presumably fixed) beam? The middle wheels, being sprung, provide some additional track contact, rather like the way that Bachmann have sprung a small number of their 3 axle locos, such as the 08 diesel shunter.

 

Might try that myself sometime!

 

 

This actually sounds doable, to be honest. I'll have a think, but... good idea!

[hayfield]

I bought a ready built kit built 0-6-0T loco, the builder made the outer two drivers rigid but the center ones sprung, keeps at least 5 of the 6 wheels on the track at one time (5 legged stool?)

[Captain Kernow]

8 hours ago, hayfield said:

I bought a ready built kit built 0-6-0T loco, the builder made the outer two drivers rigid but the center ones sprung, keeps at least 5 of the 6 wheels on the track at one time (5 legged stool?)

Same principle as those Bachmann 0-6-0s, I guess.

 

[PenrithBeacon]

I promised to upload a photo of my idea for a compensated chassis. The draughting tape is to keep everything together in case it gets too hot. 

[Guest WM183]

This is a good idea. Spring the middle axle, leave the others fixed. Imight do a Jinty first to get some practice. The High Level Jinty kit I'd designed for csb I believe?  Or can you spring the center axle on it?

[PenrithBeacon]

IIRC the HL Jinty kit is designed for beam compensation, not springing.

 

In the photos above, my arrangement is for the trailing axle to be fixed, the middle sprung and leading to be on a rocking beam as I described in an earlier post.

Cheers

[Captain Kernow]

Yes, the High Level chassis will give you the option of twin beam compensation or rigid.

 

Frankly, the Comet Jinty chassis might be an easier option as an introduction to chassis building. You could then do as Penrith Beacon has done with it, or install single beam compensation as described earlier (and described in more detail in the Iain Rice book, of course).