Topic: Pennsy A3a 0-4-0T first bits

[GregE]

The handles are soldered per Kozo's instructions:

Turn the handle from bar including the recessed center section, then drill it to fit the spindle.
then the spokes are fret-sawn out and spindle soldered in.
I liked the technique of drilling it before the sawing so you get perfect curved ends of the spokes to fit the spindle.

[Ferd]

Hi Greg
Thanks - nice little tip or trick. Did you solder the inside of the handwheel into place or was it milled from solid bar.
cheers Ferd

[GregE]

I got a few more parts done this week- axle pump bypass valve and blower valve.

To mill the little recesses around the handwheel edges I tried a technique I read of somewhere. I tapped a piece of hex brass for a fixture to index it (as I don't have a rotary table) You can do the first 6 points from the same spindle location, just turn it in the vise for each point- I used the vise jaw edge to align. Then move the work so the spindle is positioned 90 degrees to the previous spot and mill the other 6 spots.

Obviously this isn't a precision technique But for a mostly aesthetic feature it worked pretty slick, and much cleaner than I could have done by eye.

[Ferd]

Hi Greg
I had thought of doing the same thing on the Sweat Pea and Marie Estelle (converted back to a saddle tank porter). Although injectors are nice they and great for using up excess steam they seem to be easily replaced with an axle pump under motion and hand pump when stationary. Having pre heated water may make the engine more efficient in its operation.
cheers Ferd

[GregE]

Thanks Ferd- but this won't have injectors- all pumped.
So- I think no temp differential to worry about.
My thought was that it would help to have the feedwater a little warmer heading into the boiler.

[Ferd]

The down side to saddle tanks is when using feed injectors they loose a lot of effectiveness as the water heats up in the saddle tank. I would insulate it as well as possible - I have insulating material that I have access to that is supposed to be highly effective. Used under boiler cladding you should be able to keep your hands on the boiler under full steam. The material is used in industry and military applications. The downside is it only compresses down to 3/16" in thickness. Perfect for under saddle tank, and great on boilers of larger size.
cheers Ferd

[GregE]

Thanks-
I'm actually planning to make the tank operable- just feed right down to the axle pump and with a hand pump located in the little coal bunker above the rear coupler. I figure it would have more weight than the original- I'll build the tank kind of chunky -plus the water weight. It has a flip open fill lid on top that would be easy to top up from my riding car if needed.

[bambuko]

great project, I shall follow it with interest   
Possible added benefit of you choice and an idea you could consider, is to make the saddle tank non-functional out of solid metal (preferably tungsten) to improve adhesion of this tiny loco? (I am assuming that water supply will come from the trolley you will be driving on)
Chris

[Ferd]

Hi Greg
I will be eagerly watching your project develop. Have the Kozo series of books and the Switcher is a great looking loco. I like the modifications you have made. Should make a nice locomotive.
cheers Ferd

[GregE]

Well- I've been thinking about starting a larger engine for a couple years, have read through Kozo Hiraoka's Pennsy A3 book several times, and now I've started.

I did decide to build a slightly different engine though. I'm fond of the chubby compactness of saddletankers so I'm planning to build it as such rather than as the tender loco in the book. There were a few that the PRR converted from their tender locos around 1900-1902:
http://www.northeast.railfan.net/images/prr5076.jpg
http://prr.railfan.net/diagrams/PRRdiagrams.html?diag=A3a-.gif&sel=ste&sz=sm&fr=
I found drawings also in an old Kalmbach Cyclopedia at the library and was able to overlay them on scans from the Kozo book to help scale my modifications.

I've been slowly working my way through the book compiling a material list, and until I get to purchasing stock for the larger parts- frame and cylinders to start- I'm enjoying some of the small bits I have material for. These are the boiler check valves for the axle pump and hand pump. The vent spigot on the side changes orientation 90 degrees from the photo to fit under the saddle tank.