Kozo's Pennsy A3

[Inflight]

I'm just getting started on Kozo Hiraoka's live steam locomotive, the Pennsylvania A3 Switcher in 1:16 scale. Today I tackled silver soldering the Bolster Columns from chapter 3.3.



Starting with 5/16" square brass stock, a rabbit is milled on each side of the vertical bars then the thickness is reduced to 1/4" per the drawings. After some accurate hole placement for fixture screws, the parts were ready for silver soldering. I used 45% Ez-Flow silver solder and flux I purchased through ebay and a MAPP gas torch.

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After brazing, the part is bathed in a 10% sulfuric acid bath for about 5 minutes followed by quick scrub with a brass brush under running water.

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http://1.bp.blogspot.com/-hdz4H4FOF...AA4/Q99BbNacs6g/s1600/Column+in+acid+bath.jpg

Here you see a rejected component in the pickling solution.

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Only one joint is solders at a time. So, the components were then disassembled, sanded / filed, then fluxed and soldered again. The final step is to file down the screw heads and excess material. This image shows the components at different stages of completion along with one of the fixtures.

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http://2.bp.blogspot.com/-n8YjIV7zw...TOBS8C9uq1A/s1600/Columns+silver+soldered.jpg

You can just see that solder was drawn up around the head of the screw. This a sign of proper penetration and a good joint.

- Matt

 

[Allan]

Hey, Matt.
I realize this thread is a bit long in the tooth but I'm just wondering how your a progressing with your A3? I am assuming that 1:16 is 1.6" / foot?

I just ordered some material to start on the tender trucks in 1.5". I haven't picked it up yet but I want to get my lathe trued up so it can wait for a bit. Any pitfalls to be aware of? Any inaccuracies in the plans? As they used to say in our aviation safety letters, "Learn from the mistakes of others; you won't live long enough to make them all yourself". All the best.

Al

 

[Inflight]

Howdy Allen,

Well, the little A3 hasn't been worked on in about a year. I decided to stick with the 3.5" gauge 3/4" to the foot scale as described in Kozo's book.

Here is the progress on the tender thus far.

 

[Allan]

Matt , that looks gorgeous.
So what is causing your lack of traction in going further?

 

[Inflight]

I appreciate your kind words. I just haven't had the time or resources to make much progress lately, but I will get back on track at some point.

 

[Allan]

I know what that is like. I bought my lathe 9 months ago but it is only running now but not really dialed in. I still need some tooling of course but can't blow the budget on luxuries (at least that's what my wife thinks they are). I'm a realtor so time is tight for most hobby things. My other problem is that I've got too many interests and not enough time and money. My motto is, "I don't need anymore projects... well maybe just one more".
Yet knowing how way leads on to way,
I doubted if I should ever come back.

Experimental aircraft builders have a saying, "90% finished and 90% left to go". That's where most projects bog down. The initial thrill wears off and it get to slogging and then it grinds to a halt. They also say you should do something everyday- even if it is just cleaning up the shop.
Best regards.

Al

 

[grobertson10765]

Howdy Allen,

Well, the little A3 hasn't been worked on in about a year. I decided to stick with the 3.5" gauge 3/4" to the foot scale as described in Kozo's book.

Here is the progress on the tender thus far.

I am just starting the A3, completed the bogey wheels. Your project looks great - I see that you and many others have your model on rail track stock. I have not been able to find where to buy the track stock. Any tips?

Gordon

 

[Inflight]

I have not been able to find where to buy the track stock. Any tips?

On a visit to my local hobby store I asked about obtaining track in 3.5" gauge. They found some Garden Scale track consisting of brass rails on plastic ties. I then separated the rails from the ties and tossed the plastic in the trash. I made new ties using oak because that's what I had on hand, and spiked the rails to the pre-drilled ties using scale looking spikes from the hobby store.

The key was to use a drill jig to locate all the holes correctly so the track would appear straight as possible.



Matt

 

[Inflight]

The key was to use a drill jig to locate all the holes correctly so the track would appear straight as possible.

Here are a couple of photographs of the simple drilling jig I used to locate the very small railroad spikes correctly. If I recall correctly, I used a drill bit smaller than a #60.




Matt

 

[Allan]

Wow. I just love some of the ideas people come up with to solve problems. That is one of the great values of this site. Keep up the good work. As for me, I haven't even started yet. Too many other projects. I am in the midst of making a milling attachment for my lathe. It is slow going but coming along. I also started another related project ( never learn). I am building a tool grinding jig that Ted Hansen had in HSM a while back. I can grind by hand but it would be nice to have predictable, consistent and repeatable results.

Al