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Finney A3 - Spearmint


Christian

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Hello everyone, thought I'd give you an update.

 

Painfully slow progress, so many things seem to get in the way but winter is coming so hopefully will give me a little more time for my hobbies.

 

You will recall that I have had an issue with the buffers for the tender becouse the ones included in the kit will fould the side frames. The options would appear to be either move the buffers inwards by approximately 1.5mm each or have non-working buffers.

 

Obviously I am not interested in either option, the buffers must be in their correct position and they must work. The only solution would be to make the buffers a self contained unit just like the real thing, no pun intended. A self contained unit would not have the thread and nut sticking out the back of the buffer body so there would be no danger of it fouling the side frames.

 

I have had a few ideas how to go about this and a few of you have made some good suggestions, but all ideas really require the use of a lathe. We have touched on this subject here, the pros and cons of getting a lathe, well I decided that it was time that I made the investment and a little while ago I received a lathe and some basic tooling. So add that to the price of Spearmint, the cost of the lathe? £700.00, the satisfaction of having working self contained buffers? priceless! Why do we get ourselves involved in this hobby?????????????

 

The following pictures show the parts I made and the modifications to both the buffer body and head and should explain how it all works.

Basically the buffer body was turned so that the rear face was flush then drilled with a 3mm hole.

In this hole goes a brass section that I turned to fit this hole, the brass section was drilled all the way through 1.7mm and partly drilled 2.8mm. This alows me to use a 10BA brass chesshead bolt with the head turned down to 2.75mm.

The steel buffer head has had the thread removed and has been drilled and tapped 10BA.

 

post-6851-060756800 1288384748_thumb.jpg

 

Here you can see the completed buffer assemblies, the brass section was soldered to the buffer head using 180 degree solder, this will then allow me to solder the assembly to the chassis using 145 degree solder without any fear the I will undo any of the previous work.

 

post-6851-045026000 1288384893_thumb.jpg

 

Here the buffer are now fitted to the chassis, I have also fited out some of the detail.

 

post-6851-087785000 1288384955_thumb.jpg

 

post-6851-070166800 1288384965_thumb.jpg

 

post-6851-087810800 1288384980_thumb.jpg

 

So that is where I am upto, with all the heavy soldering out of the way, I now need to fit all of the white metal castings and the tender will be finished.

 

For anyone that is interested, Myself, Simon and Dave of Building O Giage Online will be demonstrating at the Warley show thisyear on 20th & 21st November 2010. Stand E27.

I shall be taking Spearmint to the show and she will be on display for the weekend, you are all welcome to come and visit us for a chat during the weekend, I love demonstration shows, so much fun and a good laugh, we will all be happy to answer any questions during the weekend, hope to see some of you there.

 

Hi Christian,

 

Unfortunately I can't make Warley show this year, which will probably be a relief to you as i'd sit there for hours asking, what about this bit and how does that work??:D I'll keep it to a short one though for this. How does the buffer work, I'm probably wrong but when the buffer is compressed does the 10BA bolt which is fixed to the head move within the turned brass section and then once compressed does the spring return the buffer head back to its starting point and no pertrusion at any point from the rear of the housing?? Hope this is as clear as mud.

 

Best regards Mick

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Hi Christian

From what I recall the A3's that would fit your period and current tender are 60046 Diamond Jubilee, 60084 Trigo or the well known Ftying Scotsman. The other one was 60095 but it never received German type smoke deflectors. While you are deciding it is worth mentioning that David Andrews supplies a tender just right for 60100 Spearmint and even DJH may be able to supply one. You mention an option may be to sell the tender on. Hmmm, after all your efforts and superb workmanship I would recomment keeping it to marry up with a Finney A4. I finished one last year, it really is a super kit.

 

I only mention the above because your A3 is a model of such high quality and workmanship it deserves to be just right

Regards

Bob

 

Hi

 

Not entirely coincidental that mine is Diamond Jubilee :D

 

There were 5 of those tenders attached to A3s IIRC from the research when I was determining which to do. I would never build FS on principle (just like I would never build Evening Star), so I had 4 to choose from, and DJ got my vote.

 

I quite agree you must get it right, and what better excuse to get an A4 :D .

 

Richard

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Unfortunately I can't make Warley show this year, which will probably be a relief to you as i'd sit there for hours asking, what about this bit and how does that work??:D I'll keep it to a short one though for this. How does the buffer work, I'm probably wrong but when the buffer is compressed does the 10BA bolt which is fixed to the head move within the turned brass section and then once compressed does the spring return the buffer head back to its starting point and no pertrusion at any point from the rear of the housing?? Hope this is as clear as mud.

 

 

 

As already mentioned there are a couple of drawings on my website, the last one shows how the buffer works in the compressed position - http://www.cherryclan.com/scale7/workbench/sprungbuffers.html You can click on the drawing to enlarge it, or download the drawings if required.

 

Does this help?

 

 

 

 

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As already mentioned there are a couple of drawings on my website, the last one shows how the buffer works in the compressed position - http://www.cherrycla...ungbuffers.html You can click on the drawing to enlarge it, or download the drawings if required.

 

Does this help?

 

 

 

 

 

 

Adrian,

 

That helps no end thanks very much for that. I shall attempt to replicate on my current build project,

 

Best regards Mick

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  • 3 weeks later...

Hi Christian,

 

Doing pre-build research for my Finney A3 I could not miss the outstanding quality of your soldering work. Sheer perfection!

Out goes my trusted diluted phosphoric acid, because water based flux from O Gauge Online is on its way (and so is a microflame).

 

Of course, the leaf spring discussion caught my attention as well and I came across information that might be of interest.

On page 35 of RTCS Locomotives of the LNER part 2A are given the sizes of the leaf springs: 5 in. wide and 5/8 in. thick at 3ft. 6in. centres.

Your phosphor bronze strip, Christian, is spot on and, to be fair, so are the laminated springs in the Finney kit after a healthy dose of TLC.

The two attached pictures are sections from Doncaster drawings. Although they represent front and trailing drivers of an A1 there is no reason to believe that A3's differ.

 

Looking forward to see more of your work!

 

Cheers, Jan

Netherlands

post-8188-091997300 1290711033_thumb.jpg

post-8188-045982500 1290711050_thumb.jpg

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Hi Christian,

 

Doing pre-build research for my Finney A3 I could not miss the outstanding quality of your soldering work. Sheer perfection!

Out goes my trusted diluted phosphoric acid, because water based flux from O Gauge Online is on its way (and so is a microflame).

 

 

Cheers, Jan

Netherlands

 

Jan,

 

Like you, I have been most impressed by the "crispness" of CHristian's soldering.

 

As phosphric acid flux is water based, I was intrigued to see what this magic flux contains. The spec. sheet quotes 12% citric acid, 14% salt-sour zinc (I can't find this from an internet search), 7% glycerine, water, wetting agents, etc.

 

The 12% water based phosphoric acid that some of us use has less active ingredients in it.

 

Cleaning the model after every building session is good practise and readily removes residues of water based flux such as 12% phosphoric acid. I have only had problems with Powerflow and Carrs Green, which seem to require fairly rigorous cleaning.

 

Jol

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Of course, the leaf spring discussion caught my attention as well and I came across information that might be of interest.

On page 35 of RTCS Locomotives of the LNER part 2A are given the sizes of the leaf springs: 5 in. wide and 5/8 in. thick at 3ft. 6in. centres.

 

The two attached pictures are sections from Doncaster drawings. Although they represent front and trailing drivers of an A1 there is no reason to believe that A3's differ.

 

Cheers, Jan

Netherlands

 

Humm, nothing is quite so easy when staring at the A4 general arrangement drawing. Here are extracts for the leading, driving and trailing coupled axles and the details show that A4s had the same spring for each wheel.

 

post-4085-090688300 1290717776_thumb.jpg

Leading coupled axle

 

post-4085-028875800 1290717836_thumb.jpg

Driving coupled axle

 

post-4085-021445900 1290717990_thumb.jpg

Trailing coupled axle

 

What is surprising is that the A4 has longer springs, with the same number of thinner plates (no indication if of same steel specification), than those of the A1 drawing. The differences suggest that the A4 was given softer springing... was that not the cause for excessive rolling of the A4 and the introduction of "checks" between the bogie frame and the mainframe?

 

 

Interesting that the "leading" extract gives the centres of the spring hangers as part of the spring description whilst the "driving" extract gives the distance between the centres of the head of the spring hanger bolts.... and the "trailing" gives only the dimension between some location on the spring hanger bracket.

 

Christian, can we have an off-forum discussion about the different versions of spring castings along with the dimensions of the relevasnt centres?

 

regards, Graham

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Jol,

 

I suppose "salt-sour zinc" is Zinc Chloride and a wetting agent could, for example, well be Isopropyl Alcohol.

Nothing magic really, but it obviously works (can work I should say) like magic in combination with consistent after the job cleaning.

 

I came to use diluted phosphoric acid by reading Etched Loco Construction by Iain Rice long ago.

Nothing wrong with PA, but if there is a better solution :rolleyes: one should give it a try. We have seen proof of that.

 

Jan

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Jol,

 

I suppose "salt-sour zinc" is Zinc Chloride and a wetting agent could, for example, well be Isopropyl Alcohol.

Nothing magic really, but it obviously works (can work I should say) like magic in combination with consistent after the job cleaning.

 

I came to use diluted phosphoric acid by reading Etched Loco Construction by Iain Rice long ago.

Nothing wrong with PA, but if there is a better solution :rolleyes: one should give it a try. We have seen proof of that.

 

Jan

 

Jan,

 

I wonder if the solution is really in Christian's skill and the effort he puts into cleaning up afterwards.

 

IIRC zinc chloride was one of the main constituents of Bakers Fluid, which some modellers still prefer.

 

Jol

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Jan,

 

I wonder if the solution is really in Christian's skill and the effort he puts into cleaning up afterwards.

 

IIRC zinc chloride was one of the main constituents of Bakers Fluid, which some modellers still prefer.

 

Jol

 

 

I fully agree.

Sitting in a Ferrari alone doesn't make one a champion.

But it helps...

 

Jan

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  • 2 weeks later...

Evening All,

 

Was nice to meet a few of you at the Warley Exhibition last month, we all had a great time. Spearmint had her first public outing and although not finished, you comments and praise were most apprieciated.

 

One of the main topics asked me during the weekend was the driving wheel springs, I have been asked to post some more photos of the springs so while I had the chassis totally stripped down last weekend, I took some.

 

As you may have read in an earlier post, the springs and custm made using the hangers from the Ragstone Models castings, I cut the spring part away and made up my own springs phospher bronze strip. You can go back to an earlier posting to see exactly how I made the springs up.

 

Here are the close up photos of the spring and hanger units fitted to the chassis.

 

post-6851-046149100 1291756009_thumb.jpg

 

post-6851-061166000 1291756020_thumb.jpg

 

post-6851-005483600 1291756032_thumb.jpg

 

I have also included the picture of the four options for the spring units.

 

post-6851-028233500 1291756134_thumb.jpg

 

For reference, top left is supplied by Hobbyhorse, top right is supplied by Sanspareil, bottom left supplied by Ragstone Models, and bottom right etches included in the kit.

 

The chassis had bee stripped down so that I can fit the sanding gear pipes to both the front and middle wheels. I have also changed the three axles, the wheels are now set at the correct 120 degrees.

Another modification is to the return crank. I have never been happy with the fit, the crank is a loose fit over the thread of the crank pin and difficult to position correctly.

So on the centre crank pins, I have drilled out the bushes and tapped them to 10BA. A 10BA Brass bolt is now used to hold the crankpin bushes in place and the end of the bolt squared off so that the return crank has something to align with. The fact that the bushes have been tapped means that the crank pin can be set and secured correctly to the wheel.

The return crank is now a force fit over the squared crank pin and it aligns perfectly.

 

Here is a picture of the wheel with the new crank pin and bushes.

 

post-6851-036952400 1291756866_thumb.jpg

 

I shall take some more photos of the chassis once it is cleaned up and re-assembled.

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  • 2 weeks later...

what position will you be having the smokebox number?

 

I always thought they looked better with the number on top of the top smokebox strap like this... http://kettlesgalore.../p66648342.html

 

when placed above I think they didnt look as good http://kettlesgalore.../p64171941.html

 

also, spearmint with yellow cabside stripe, how about this? brave man to do it I think, http://dwb.railsteam.../p22465317.html

 

Mike

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what position will you be having the smokebox number?

 

I always thought they looked better with the number on top of the top smokebox strap like this... http://kettlesgalore.../p66648342.html

 

 

Hello Mike,

Yeah pretty much like in this photo, great photos by the way, thank you. I am always on the hunt for any pictures of Spearmint especially in her later years.

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Brian, that looks fantastic, I dont mind the yellow stripe, its one thing my dad hates and always bores me about it when he see's one

I think it was you who said it adds a splash of colour and I agree, although for some reason I dont know if I could bring myself to do it if it where my own.

 

Christan, good choice :) I dont really know a lot about eastern region locos, but always thought they looked odd above the door strap, the smokebox door is its "face" if you like.

 

I dont like when they have the straps polished up either. unless in apple green,

 

Ive been in a heated debate on another forum about how scotsman should be preserved, I think it should be BR green if its got deflectors etc, but lets just say not a lot of people agree :)

 

Mike

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