Help with Kumata Trainmaster Reconstruction

[ChristianJDavis1]

Just the other day, I managed to buy a Kumata PRR Trainmaster from a friend for only $25.00. Here is what I have of it:

Unfortunately for me, though, it is missing quite a few parts. From what I can see, it is missing one gear from the gearbox (see pictures), various-sizes of screws to hold its components together (see pictures), wiring, the metal rod that holds the truck on (see pictures), a piece of the driveshaft (see pictures), and maybe even other things I cannot see.

If anybody knows anything about these Kumata Trainmasters or brass in general, and have any advice for finding parts or how to rebuild this engine, and information would be appreciated.

The following are some pictures of the various parts, where it is obvious that things are missing:

[Bob Horn]

Ron Beardon, u18b is the man!! Bob.

[spookshow]

Ron just recently tuned his Kumata Trainmaster to the point that it runs at least as good as an Atlas Trainmaster. If anyone can help you, he'd be the one.

Good luck!
-Mark

[u18b]

I'm on my phone right now and scrolling with photos is difficult.  I'll be back at my dedktop later on.

[u18b]

Christian.

Screws can be re-tapped for a different size.
U-joints can be replaced with more modern ones.

But the part that is pretty much irreplaceable is the screw that holds the main drive gear.  It is NOT a knockout pin.  It is a headless screw.  Without that, it becomes more challenging.

To be honest, without that screw, I don't know that the loco is easily repairable.

You could sell it for parts.  You should easily get 35.  Two broken SD40-2s by Kumata recently sold for about 50 bucks in the last week.   Your shell is painted and nice.

Your other option would be to hunt for another broken Kumata.   Your best bet (one's that seem to be broken more often) are the SD40-2, ALCOs, and the Trainmaster.

If you can get another screw/pin,  I can show you how to get it running well.

Sorry.
Ron

[johnh35]

Christian.

 But the part that is pretty much irreplaceable is the screw that holds the main drive gear.  It is NOT a knockout pin.  It is a headless screw.  Without that, it becomes more challenging.

 

Ron, is it threaded on the end but machined down to a shaft as it passes through the gear? Is it an internal wrenchinh hex or a slot on the end? If you or Christian can post a picture and it is what I think it is, we use similar screws on some of the aircraft controls that we work on.

[mmagliaro]

As for that threaded screw/pin that is missing, yes, if Ron or somebody can post a photo of what that looks like,
and measure the diameter of the pin where it passes through the gear (with a caliper), I have ideas on how that can
be fabricated without to much fuss.

A headless screw is not too hard to make.  Start with a regular screw, cut off the head with a Dremel disk, and then
carefully cut a slot into the end to make a new screw slot.  You need to use a jewelers saw, like a Zona, to do this.
A Dremel disk is far too thick.  If it's smooth in the center where it goes though the gear, that might be trickier.

[u18b]

I have photographed it.

I've made a coreldraw drawing of it.

I'm now about to make measurements as soon as I search for my calliper.

[ChristianJDavis1]

Thank you to everyone who responded. I was almost certain the headless screw would be hardest to replace, but as a temporary fix (so it can at least be a nice-looking dummy), there is a standard knockout pin in its place, which, although it is loose, is fine for now. What I really need is the screws that hold the shell to the frame, which appear to be two different sizes from the bottom of the gearbox and the frame mounts. If anyone has spare screws or anything, I would be willing to buy them (if I buy another parts unit, I will be too tempted to rebuild it like this one...). Also, what shape should the missing part of the drivetrain be? It looks like it is supposed to a rectangular prism of sorts...

[u18b]

No NO No No!   

It is NOT a standard knock out pin.  You will ruin the truck if you treat it as such.

It is a SCREW

[spookshow]

Here's a complete one if it's any help -



Cheers,
-Mark

[u18b]

I'm not very good at this, but here are my measurements.





Sorry, I forgot to measure the length of the threads.  They are about  .102"

[spookshow]

What the heck was your buddy up to anyway? Aborted re-motor project? 

-Mark

[u18b]

Max and John.

If y’all can make that thing.... I'd like to pay you for about 6.

[spookshow]

Maybe NWSL could build the threaded non-knockout pin? Pry expensive, though.

If you can't find the proper driveshaft connector, NWSL does sell various driveshaft cups and dog-bone connectors.

-Mark