workwright wrote: ↑Sat Mar 16, 2019 11:39 am
Hi, over 30 years I have built about 400 locos.
and that's why your advice is so valuable!
Thank you
... The only commercial models (40 off) that were sprung were Balwin 4-6-0 tank locos... Not a good project from the commercial side ... It sort of answers your question ..
It sort of does, but I must admit that I am more interested in your private view, rather than (perfectly understandable) commercial constraints
i.e. if you were building one for yourself, would you bother and if yes, how would you go about it?
There is plenty of examples for standard gauge practice in any gauges (from O, through 1 all the way to 5", 7" etc).
When it comes to narrow gauge in small scales, they all seem to follow commercial practice of KISS.
The only example I've seen with springing was Ross Harrison's design and even this one has been bouncy and not very good (I am told ...).
Whether it was because of bad design or bad manufacturing - I don't know, although I am sure the latter played it's part.
...So no springing on 0-4-0 locos- too fiddly...
As you say, it's common practice in 16mm scale and I guess the only way I am going to answer it for myself is by building two examples one with and one without springing, or perhaps build three, with the third one having just equalisation, without springing
(something on the lines of what Kozo Hiraoka proposed for his Penn A3 switcher)to give three point suspension.
...Of the products, Hunslet, Tattoo, Wren have 3/8" ID cylinders... I think that problems of poor running are not due to cylinder bore...
So this confirms to me, that given careful manufacturing, there is no reason to go for this bucket size cylinders as an answer to indifferent handling.
Other factor, I guess, is that all these locos which "needed" 1/2" dia cylinders had boilers at 40 PSI, whereas yours are 60 PSI.
... Have you ever seen the work of Dave Shotter? His 16mm scale 3 1/2 ton Decauville type 1 tank was minute and beautiful in all respects - probably one one the finest models of a loco ever built...not watch making, just a model of a prototype made in minature to the drawings....
No, this is the first time I hear about the gentleman (sadly no longer with us I understand...)
The photo in TonyW reply (thank you Tony!) to your post gives some idea about the kind of quality we are talking about, and it shows what is really possible.
...If you get pleasure from making things get to the bench and make...
My
0-6-2 Fowler design is making slow progress, although I got slightly delayed dithering about axle springing arrangements in this one as well
(hence some of the questions here, not just about 0-4-0 Hunslet)
...Remember that it is only rarely I have the time to make something for myself ...
and that's why I appreciate even more, your time taken to reply to my questions - thank you!
1) A Chassis must be square
2) Quartering must be precise
3) No enlarging coupling rod holes to achieve free movement(see 2)
4) pinning + loctite is safer than loctite on its own
Amen to that as well!
My frames are brazed to buffer beams, making it very solid design, with final sizing in a milling machine (including axle slots, hornblocks etc) afterwards for accuracy and precision.
Wouldn't make sense as a commercial proposition,
but luckily for me I have no "clock ticking"
(apart from the limit imposed by grim reaper waiting for us all...
)