The Home Machinist!

Hi Chris According to James L Ehernberger's book "Challenger Portraits": 3950 was built at Alco-Schenectady, May 1942, constructor's number 69760. 3976 was built at Alco-Schenectady, June 1943, constructor's number 70159. From William W Kratville's book "Big Boy": 4012 was built ...

Hi Chris
According to James L Ehernberger's book "Challenger Portraits", 3976 was built at Alco-Schenectady, June 1943, constructor's number 70159.
David

Hi Berne, These will be what is known as Model Engineer (ME) threads. They are Whitworth form 55 degrees, BSCy threads are 60 degrees. The larger ME threads are also common with British Standard Brass (BSB) threads. I believe they are available in the US, taps and dies are certainly available in the...

Hi Anthony, Many thanks for the update. I must say I was very impressed with your video on the small injectors, that was what made me finally decide to place an order! That's really useful information about the pipe sizes, very relevant as my engine is a mixture of 3/16" and 1/4". David Or...

Hi Mark, You might also find interesting the Wikipedia page for Gresley conjugated valve gear and Holcroft conjugated valve gear: https://en.wikipedia.org/wiki/Gresley_conjugated_valve_gear https://en.wikipedia.org/wiki/Holcroft_valve_gear#:~:text=The%20Holcroft%20valve%20gear%20was,%26%20Chatham%20...

Hi Adam, I went through the same process a while ago. Agreed that Amphenol mil-spec connectors seem overkill. What I found and ended up using was the Souriau UTS series of connectors. These are a plastic-body version of a mil-spec connector and are available from 2 to 32 contacts. Much cheaper than ...

Hi Chris, Many thanks for the explanation and the pictures, really interesting and very informative. That's a really impressive building stand, you certainly need some heavy duty equipment to tackle a project like this. That makes sense about using the stand to rotate the chassis. Excellent idea to ...

Hi Chris, Can I ask about the loco stand please? Is the stand now just for raising the engine to work underneath it? I can't imagine being able to rotate the complete engine, unless you have a magic way of stopping it articulating! I can see the additional support you have, just behind the rear cyli...

Amazing work Chris, just love all the detail. Mere words are not enough! :D For interest, I have a little more information on the original 3976: In the Union Pacific Historical Society book: Prototype Locomotive Photos Volume 37, there are 3 pictures of the 3976. The first picture, dated ca. 1948, s...

It's definitely 3/4" = 12" scale, or to put it another way, 1/16 scale.

Interesting that in the UK, locomotives etc. are much more usually referred to by their gauge, rather than scale. In this case, the loco is 3 1/2" gauge.

David

As you say, an exhaust deflector. It helps prevent a warm, wet, oily shower for the driver, passengers and onlookers! Many club visitors don't like going home after a day out with their clothes spotted with oil...

David