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Re: bambuko loco works 0-6-2 (Fowler)

Posted: Thu Dec 05, 2019 7:31 pm
by Hydrostatic Dazza
You are doing such a nice job, put a grate in and burn the black stuff.

Re: bambuko loco works 0-6-2 (Fowler)

Posted: Thu Dec 05, 2019 8:35 pm
by bambuko
Hydrostatic Dazza wrote: Thu Dec 05, 2019 7:31 pm You are doing such a nice job, put a grate in and burn the black stuff.
Thank you.
I would like to do it indeed :thumbright: but this particular model would need too much butchery to rear of the cab to permit easy access for the shovel.
Plus, adding axle pump at this stage would be a bit of PITA
I will leave it for the next one :mrgreen:
Having said so - this mod is not impossible and the way this project is meandering you never know where it might end up :D

Re: bambuko loco works 0-6-2 (Fowler)

Posted: Tue Dec 10, 2019 6:28 pm
by bambuko
Something slightly different (i.e. no update, although I am making progress :thumbright: )
Here is one of the original, Leeds build Aussie Fowlers that made it's way back to UK:



She is in "Steam Workshop":

https://www.steamworkshop.co.uk/portfol ... ler-16341/

and here as she was in Australia:

http://www.australiansteam.com/fowler16341.htm

and more photos:

http://www.steamworkshop.co.uk/portfoli ... s-fowlers/

Shame I got the vids and photos only now and not when I was designing my model (which suffered from desperate shortage of decent photos of original)

OK, she is 0-4-2 not 0-6-2 (which I am building) but other than that she is much of the muchness...
Not surprising since someone like Fowler wouldn't be re-inventing the wheel every time it build a locomotive :mrgreen:
Lot of common components and familiar design aspects.
Hope you guys enjoy it as well :study:

Re: bambuko loco works 0-6-2 (Fowler)

Posted: Wed Dec 11, 2019 8:46 pm
by Hydrostatic Dazza
bambuko wrote: Thu Dec 05, 2019 8:35 pm
Hydrostatic Dazza wrote: Thu Dec 05, 2019 7:31 pm You are doing such a nice job, put a grate in and burn the black stuff.
Thank you.
I would like to do it indeed :thumbright: but this particular model would need too much butchery to rear of the cab to permit easy access for the shovel.
Plus, adding axle pump at this stage would be a bit of PITA
I will leave it for the next one :mrgreen:
Having said so - this mod is not impossible and the way this project is meandering you never know where it might end up :D
There were articles in AME magazine in 2017, they did thermal modeling of what happens in a coal fired wet leg boiler when run dry. The temperature rise was very little and well within the brazing and copper material stability, due to the draft on the fire ceasing as soon as the water was gone. thus in the small garden size grates, the fire dies to a ember. (if you use soft solder well ??) They backed this up with actual testing and measuring temperatures and all was very close to the thermal modeling. I saw this in action on the loco at my local ME club run. They have a small garden track there now. I know many will be :roll: with the concept of a coal fired garden steamer without a pump, but like many things, once the notions are wide spread, then the notion is all blanketing and perpetuated for decades it is hard to dispel. So maybe you do not need a pump if the boiler has wet legs and the design has a decent water volume for long runs. (less tubes) I am putting a pump in my build to just give the option of a lengthening the run, thinking it will be 30 -40 minutes with a slow trickle that will be just below the steaming rate. Still able to run it dry, it just gives more wine and smelly cheese time . Did I email the scans of these AME articles to you ?

Re: bambuko loco works 0-6-2 (Fowler)

Posted: Thu Dec 12, 2019 11:12 am
by bambuko
Hydrostatic Dazza wrote: Wed Dec 11, 2019 8:46 pm ...There were articles in AME magazine in 2017, they did thermal modeling of what happens in a coal fired wet leg boiler when run dry ...I saw this in action on the loco at my local ME club run...
How does it square with the boiler code which requires you to have two independent sources of feedwater (regardless of boiler size)?
I am not saying that the article was wrong, simply asking how can you run (in a club environment) something that does not adhere to the code?
What you run in your private back garden is your own business, but in public... it's another story?
Hydrostatic Dazza wrote: Wed Dec 11, 2019 8:46 pm ...I know many will be :roll: with the concept of a coal fired garden steamer without a pump...
Yes :mrgreen: and that's why I think that sharing a boiler code with "big guys" is a bit of a problem.
Hydrostatic Dazza wrote: Wed Dec 11, 2019 8:46 pm ... Did I email the scans of these AME articles to you ?
Yes, you have - thank you very much!
I personally dislike axle feed pumps in smaller scales, so these articles are very encouraging :thumbright:

Re: bambuko loco works 0-6-2 (Fowler)

Posted: Thu Dec 12, 2019 6:13 pm
by Keith S
Those "Riverdale" boilers don't have feed pumps. Apparently designed to carry enough water to last until fuel exhaustion. I wonder if the design takes into account that the fire will die when the blower stops. I've seen them running at expositions in public, so must be insurable at least under the 16mm association guidelines.

Re: bambuko loco works 0-6-2 (Fowler)

Posted: Thu Dec 12, 2019 7:36 pm
by bambuko
Yes, just been through Riverdale webpage.
The arguments (with which I totally agree) against the use of axle pump are very well explained by Brian Wilson in this August 2014 article in "16mm Today" magazine:
https://www.riverdale-loco.com/Today.pdf

So I guess, you are right - it is acceptable to the insurers etc.
Makes a mockery though of the boiler code we are supposed to adhere to? :scratch:

Re: bambuko loco works 0-6-2 (Fowler)

Posted: Fri Dec 13, 2019 2:51 pm
by TonyW
bambuko wrote: Thu Dec 12, 2019 7:36 pmThe arguments (with which I totally agree) against the use of axle pump are very well explained by Brian Wilson in this August 2014 article in "16mm Today" magazine:
https://www.riverdale-loco.com/Today.pdf
I'd forgotten about that article, so thanks for posting the link. I have a Shawe Steam Services / Roundhouse "Jack" which has an axle pump. I must be doing it all wrong.
bambuko wrote: Thu Dec 12, 2019 7:36 pmSo I guess, you are right - it is acceptable to the insurers etc.
Makes a mockery though of the boiler code we are supposed to adhere to? :scratch:
For clarity, to which boiler code are you referring?

Re: bambuko loco works 0-6-2 (Fowler)

Posted: Fri Dec 13, 2019 4:06 pm
by bambuko
TonyW wrote: Fri Dec 13, 2019 2:51 pm ...For clarity, to which boiler code are you referring?

in UK - The Boiler Test Code 2018:
6.5
Boiler water feed arrangements shall be by at least two independent means
(two of each, or a combination of, hand pump, injector, mechanical pump, etc.).
A single boiler inlet with two check valves is acceptable.
later edit:
Correction - above is from Volume 1 (for boilers above 3 bar litres), so it doesn't seem to apply to "our" boilers, which are covered by Volume 2.
The only reference to boiler water feed in Volume 2 is as follows:
The boiler may also be fitted with a water level gauge and a mechanical means of pumping water into the boiler whilst under working pressure. If no means of supplying water to the boiler whilst working is present, the fuel supply shall be so arranged that it is used up before the water is exhausted.
So it seems that it is all optional? :D



in Australia - AMBSC Code Part 3:
2.5.3
The boiler shall have at least two feedwater systems one of which shall be an
axle pump or other device that will maintain water level while the engine is in operation.
later edit:
This one definitely applies, regardless of size of the boiler (AFAIK)

Re: bambuko loco works 0-6-2 (Fowler)

Posted: Sat Dec 14, 2019 8:58 pm
by Hydrostatic Dazza
“in Australia - AMBSC Code Part 3:
2.5.3
The boiler shall have at least two feedwater systems one of which shall be an
axle pump or other device that will maintain water level while the engine is in operation.
later edit:
This one definitely applies, regardless of size of the boiler (AFAIK)”


You may be looking at the incorrect document, are you referring to sub miniature boilers
AMBSC Code part 3
Issue 2.00 -2017
Sub- Miniature Boilers.

(which is the latest one that I know of)

There is no mention of 2.5.3, it actually does not exist in the document I have. (last listing in section 2 is 2.3.14)
There is no mention of feed water systems at all in the document. I have not seen many meth fired pot boilers with hand, axle pumps or injectors.

I will also add that as an engineering document it is has many problems. One example, there is no reference to boiler barrel wall thickness. It has been reported by others that the process of creating the current AMBSC sub miniature boiler code was fraught with problems, even contempt for the smaller scales and submissions by those who work in the smaller scales, so there are moves to create a new separate code for sub miniature boilers.

Re: bambuko loco works 0-6-2 (Fowler)

Posted: Sat Dec 14, 2019 9:41 pm
by bambuko
I am referring to the same document, but I haven't got the latest version (mine is 2006), so it might be that it has changed...
Section 2.5 (in 2006 version) is Coal Fired Boilers

Yes, I am aware about the moves to create separate code.

Re: bambuko loco works 0-6-2 (Fowler)

Posted: Thu Apr 16, 2020 1:26 pm
by bambuko
Trailing pony truck.
The combined truck bearing/gas burner holder:

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Outside fames with bearing pad:

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And the same from below, with wheels, axleboxes and springs:

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Pony truck assembled and ready for fitting to the loco:

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Detail of axlebox:

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Pony truck secured to the loco:

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On the rails:

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and that is prototype ve model:

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The springing is very light, just enough to keep trailing pony wheels in reliable contact with rails, without affecting main wheels.
Tested on some dodgy track and delighted with the way it works :thumbright:

Re: bambuko loco works 0-6-2 (Fowler)

Posted: Thu Apr 16, 2020 1:37 pm
by tom_tom_go
Very elegant!

Re: bambuko loco works 0-6-2 (Fowler)

Posted: Thu Apr 16, 2020 2:15 pm
by bambuko
Thank you ttg

btw - more updates from the restoration of full size Fowler at Steam Workshop :


Re: bambuko loco works 0-6-2 (Fowler)

Posted: Thu Apr 16, 2020 11:25 pm
by Hydrostatic Dazza
Marvelous stuff with the truck. Keep the photos coming !!!
and the video is interesting. I would have invested in a needle gun to clean up the wheels etc.
I know the feeling of tube grinding in the fire box.

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Re: bambuko loco works 0-6-2 (Fowler)

Posted: Fri Apr 17, 2020 8:20 am
by bambuko
Thank you Dazza!
Any praise coming from you, is particularly nice indeed :thumbright:
It would have been great to have mouldings from Mike in NZ for both pony truck frame and axleboxes.
Maybe next time...
For now it is just rough, coarse representation of swing link truck in the prototype, but it will do (especially from 10ft away :mrgreen: ).
Main thing is, that functionally it promises to work OK.

Re: bambuko loco works 0-6-2 (Fowler)

Posted: Fri Apr 17, 2020 10:05 am
by FWLR
Well I for one think you've done a really superb job. It just looks so professionally done. You should be really happy with how well you have done with what could and can be a real pain to get right.

You have in abundance...

Re: bambuko loco works 0-6-2 (Fowler)

Posted: Fri Apr 17, 2020 10:15 am
by bambuko
:D
It took two attempts to get pony truck frame right ...
and the second time I put (almost) as much time into making a fixture that held everything for silver soldering as I did into making the bits for the frame :thumbup:

but I got it right in the end - if you look closely at the photos you will see even solder lines at 0.15mm :king: all around.

Re: bambuko loco works 0-6-2 (Fowler)

Posted: Thu May 07, 2020 5:26 pm
by bambuko
Next update is about cranks.
First a "test run" to make sure everything works as planned :thumbright:
I have spare axle with wheel from when I was making them, so will use this and one test crank to check some of my ideas.

Each crank starts as a rectangle of steel, with holes drilled and reamed (using DRO means everything should be quite accurate):

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Next the crank start taking shape:

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Balance weight are angled at 20deg, so simple fixture makes sure they will look OK:

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Round face of balance weight is turned on the lathe, using simple mini faceplate:

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It even has little "dog" to push crank round - when I first tried without it, just using centre screw and relying on friction, things went pear shaped :mrgreen:

and.. finally little buttons and bit of filing to round the crank.

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Didn't have silver steel to make them hardened, but regular mild steel was just fine for one off (silver steel on order)

That's it for today. Next... crankpins and loctiting and pinning it all in place.
Which leads me to a question:
In Brian Wilson's book both crankpin and axle are pinned to the crank (page 22).
Axle bit makes perfect sense, but why pin crankpin? - it's not as if it is going to twist itself off (unlike possibly axle/crank joint).

Re: bambuko loco works 0-6-2 (Fowler)

Posted: Thu May 07, 2020 10:23 pm
by Hydrostatic Dazza
For what it is worth, I made the driving crank pin from silver steel (or was it an off cut of a 1/8" HSS drill shank?) as it was pressed on and did not need any threads. The eccentric crank will be cross pinned using 1.00mm HSS drill shanks, this is yet to be done after test steaming. The rest of the pins I made as per BW book and I case hardened the threaded pins with "Cherry Red" , which seems to work well. Not sure how deep the case hardening goes but a file skids over it. I used PB for the rod bushes. I cannot see why you would cross pin the crank pins to the cranks. I could not find where B. W mentions this in the book ??
I made the Quartering jig as like in the book and added lock nuts to the centre screws to enure they did not wobble about and also wooden wedges to ensure positive engagement of the pins to the jig. I felt this was very worth the effort.


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