The Home Machinist!

Hello James,

Having traveled the road you are contemplating here are a couple of my thoughts.

The erection drawings leave out a lot of details, especially piping and appliances. You will find that locomotives built for other railroads, and/or different classes on the same railroad, used the same or similar parts. To help with my project, a 1930 built Baldwin 4-8-4 built for the Southern Pacific Railroad, I used Lima erection, frame, piping and several detail part drawings for the GS-2 and later classes, drawings from classes ranging from 4-6-2's through the articulated locomotives and not limited to the Southern Pacific. The William Kratville drawing book of the UP FEF class 4-8-4's, drawings from the California State Railroad Museum for the Timkin 4 aces, PRR drawings for the tender buffer, the Union Pacific Historical set of drawings for their 0-6-0 through Big Boys and on and on. I purchased as many photographs as possible especially views other than the standard 3/4 view. As with the drawings you may find photographs of similar locomotives helpful. I have also traveled to several museums with similar locomotives on display and took as many detailed photographs as I could. Some examples are here on my Flickr page.
https://www.flickr.com/photos/dyungling/albums

Along with the lathe and mill, were you to want to fabricate assemblies like trailing trucks, rods and valve gear, a CNC mill along with a heliarc welder have proven quite useful. The mill does not need to be a machining center as a Bridgeport size has proven quite adequate for all of the projects myself and my dad have built. Some examples are in this thread.
http://www.chaski.org/homemachinist/vie ... 4&start=12

The mill being used is from the early 1970's built by Wells Index. It has been upgraded through the years with most of the original electronics replaced with a PC and driver cards. Without this machine fabricating my tender and trailing trucks would have taken years longer if machined on a conventional mill. This mill has also proven to be quite valuable in the construction of lost wax molds sunk into aluminum cavities.

Be sure to follow all of the build threads on this board there is a lot of good info being shared.

Fabricating parts will in many cases take considerably more time than machining a casting. Fabrication, or making your own patterns will give you a more accurate model. I also had the advantage of my father's vast knowledge in designing and building steam locomotives. Without his experience my locomotive would have never been attempted. My 4-8-4 is the second locomotive I have built and many parts for others were made before I started my project. That experience is what helped me get started with my own project.

Mike is making some very good points about using commercially available parts and designs.

Good luck with your project and keep us posted with your progress.

Donald

not to open Pandora's box, but please do not believe for a minute that a CNC anything is required to build a steam locomotive.

Nice to have - absolutely...but required?

Nah....

MANY a locomotive has been built with a lathe, drill press, milling attachment for lathe (small loco) and / or a manual mill.

Bill Shields wrote:not to open Pandora's box, but please do not believe for a minute that a CNC anything is required to build a steam locomotive.

Nice to have - absolutely...but required?

Nah....

MANY a locomotive has been built with a lathe, drill press, milling attachment for lathe (small loco) and / or a manual mill.

I do not believe I said a CNC mill was required. What I am saying is that for parts like the sides for my training truck and Tender trucks to be fabricated, the CNC saved me more hours than I would like to think about, and allowed profiles that matched the drawings. The same goes for some of the geometry on rods and valve gear. For example, the rear of my main rod is elliptical in shape and that was a detail I wanted to incorporate when machining the rods. The CNC made that profile easy to machine. The post to Ward's SF 2900 article shows the methods we use in place of patterns and castings.

When I decided to build the GS-1 there were no commercial parts that would have lent themselves to an accurate model. We made, or had made, some patterns, including drivers, domes and tender backhead. Almost everything else was fabricated. Could I have built my locomotive without the use of the CNC, sure, it just wouldn't have been built to the standard I am trying to achieve. Am I a professional machinist, no, but I have been around those who were and their skills I try to emulate every time I try to make a part.

I also know of machinists who used Troyke tables on manual mills and made amazing parts including lost wax molds. Unlike a numerically controlled machine where the entire part is usually profiled in one setup, the manual mill requires careful positioning for each curve. In the world of machines there is usually more than one way to achieve the desired results.

The original poser asked for thoughts and I shared mine, right or wrong, it doesn't matter. It is how my particular locomotive was built.

Donald

I just don't want to frighten the guy off by having him think such is a necessity.

He is going to have a tall enough mountain to climb as it is without thinking that things cannot be made with files, grinders, belt sanders and the occasional sabre saw to cut sheet metal.

Dear Fly

As I understand it there was at least one person that got copies of the blueprints, before they were given or exchanged to the PRPA. Blue prints are for the engine but it was also hoped that CD/DVD would be made and then sold for the up keep of the locomotive. I could try and get the gentleman name who got copies since this was done before PRPA received the prints. The big difference in the little ALCOs is in the boiler size and the jugs, hers are more in line with C&O such as 614. Trailing truck is different than most. Steam dome over boiler checks, firebox is the longest for a northern, except for challengers and big boys. Most of the specs are on line. By the way if the 700 had not gone to the Spokane Portland and Seattle she would have been the NP2668 A-3.

Clint

Highiron wrote:...Why yes it is Bill...thats Paulies 2D MAD (Manuel Aided Design)...LOL

Don't laugh...I've got one just like it!

Here's a blast from the past, in answer to another question:

http://www.chaski.org/homemachinist/dow ... &mode=view

Built from "Baldwin Erection Cards"

John

actually ....I do also...buried under a pile of old computer stuff....

Hi Everyone,

Thank you for all the informative replies. I have a set of prints coming from Little Engines. I will use this as my starting point to see what elements relate to the locomotive I would like to build. I am also still working on sourcing the drawings for the Northern Pacific 4-8-4 or SP&S 4-8-4, thanks to a few extremely helpful members on this board, it looks like that may be a possibility.

Thanks again for all the help

James

Hi James,

One item to look at early on is does the NP A3 have a one piece cast engine bed vs. the older girder style frame. I had looked at building a CB&Q O5, a 4-8-4. Since I had never built a live steam locomotive before, I bought a set of Mike V's old Northern prints. The O5 has a one piece cast engine bed with integral cylinders. There were a lot of other differences.

I started design work but then decided to move in a different direction. I did not want the design work to take longer than building the locomotive. And I had way too many questions. I am now doing a Mikado. This process is giving me a lot of practical experience.

But there is a lot to be said for building what you really want.

Good Luck.

Dale

Hi Dale,

The O5a is a beautiful engine, I considered it when picking between 4-8-4's. I completely agree in that I do not want to spend more time re-engineering a locomotive than building one. The Northern Pacific A3 does indeed have a one piece cast engine bed with integral cylinders. One thing that sets this locomotive apart from others that I have seen is that it not only has integral cast cylinders, but integral cast air tanks as well which are between the frame. I have a picture in my locomotive cyclopedia of a engine bed with integral cast air tanks. I'm not sure which locomotive or road that frame belongs to but it sure is interesting. Did you have much machining experience before you took on your Mikado project?

Thanks

James

NP A-2 #2650 3/4 view
http://digitalcollections.smu.edu/cdm/s ... 182/rec/24

NP A-3 #2667 side view
http://digitalcollections.smu.edu/cdm/f ... tem/rec/25

Donald