very rare brass Key 4-10-2 Southern Pacific

[u18b]

I recently had the wonderful opportunity to examine a very rare brass locomotive.  These hardly ever appear on ebay and they are pretty expensive when they do.  It belongs to Mark Spookshow Peterson.  He picked it up for review to add to his great encyclopedia.
http://www.spookshow.net/locos.html

It had a slight bind in the drive train and he sent it to me to look at.  One of the bearing suspension springs had gotten out of place.

Since this was such a rare loco, I thought I would share with you.  It is a very impressive model.
It is the most detailed loco I've been privileged to examine.
It is really impressive.

I'm guessing after Mark is finished reviewing it, he'll probably be selling.  If you might be interested, contact him and see if he wants to part with it.

[JMaurer1]

All I know is that if he sent it to me, it would have gotten lost in the mail. That would be my story and I'm sticking to it.

[peteski]

That is a gorgeous model, with a level of detail I would expect in H0 scale.

[mmagliaro]

I love the detail.  The piping and smaller details are very delicate and in scale.  (a lot of older N Scale brass, while prototypically accurate, has kind-a "chunky" detailing).

Those drivers look magnificent with nice fine flanges.  Is there any way you could measure the driver size with/without flanges and the overall wheelbase?  There is another thread on here about doing x-10-x and x-12-x locos and the how to mash all those drivers close enough together with flanges to make it workable, so I'm curious as to how close these are and how big the flanges actually are.

[woodone]

You are saying that the driver axles had springs? WOW, they must be really small.

[Mike Madonna]

Very impressive! IRCC, Samhongsa built brass steam is equipped with "sprung" drivers. The Sam built MT, GS, AC and C class SP steam has this feature. I find it interesting that the box states "5047 Late Version", yet the loco itself looks to be an "as delivered" version with road number 5000 (the first SP-1), "Southern Pacific Lines" (Pre-1946), Spoke pilot and number boards in the original position on the boiler. Oh, did I say that it's absolutely gorgeous?!?!?! 

[peteski]

You are saying that the driver axles had springs? WOW, they must be really small.

Yes, many brass steam locos have sprung driver axles, but in my experience those springs are way too stiff to actually result in a workable suspension. Springs are slightly large diameter than the MTL coupler springs, but they are wound out of much thicker steel wire (much, much stiffer than the coupler springs).



Here is a photo of a loco I worked on. The frame is shown upside down and the springs (little silver things) are still in the bearing slots. 

[Mike Madonna]

Peteski,
WOW, that is really stripped down!
May I ask what needed to be done?
I concur on the springs being a bit "stiff"....

[peteski]

Peteski,
WOW, that is really stripped down!
May I ask what needed to be done?
I concur on the springs being a bit "stiff"....

That was a fun project!  My favorite part of this hobby is taking models apart (and reassembling them, preferably adding more parts then they originally had).
See https://www.therailwire.net/forum/index.php?topic=36396.0

[u18b]

I love the detail.  The piping and smaller details are very delicate and in scale.  (a lot of older N Scale brass, while prototypically accurate, has kind-a "chunky" detailing).

Those drivers look magnificent with nice fine flanges.  Is there any way you could measure the driver size with/without flanges and the overall wheelbase?  There is another thread on here about doing x-10-x and x-12-x locos and the how to mash all those drivers close enough together with flanges to make it workable, so I'm curious as to how close these are and how big the flanges actually are.

Max, I have not had a chance to mail it back yet, so I'll measure tonight.

[Point353]

What would be the minimum radius for this model?

[u18b]

My experience was as you would expect. 
19” runs fine.

At 17” the pilot truck would periodically derail.

Funny thing is that in spite of the very long driver wheel base, the loco can actually run fairly well on 15”.
So it’s the pilot truck that’s the problem.

So who knows, someone who is good at steamer tinkering might be able to improve pilot truck.

[u18b]

I love the detail.  The piping and smaller details are very delicate and in scale.  (a lot of older N Scale brass, while prototypically accurate, has kind-a "chunky" detailing).

Those drivers look magnificent with nice fine flanges.  Is there any way you could measure the driver size with/without flanges and the overall wheelbase?  There is another thread on here about doing x-10-x and x-12-x locos and the how to mash all those drivers close enough together with flanges to make it workable, so I'm curious as to how close these are and how big the flanges actually are.

Max, my apologies.  I didn't want to disassemble it one more time to make measurements, so I made them with the shell on and thus have a bit of estimation.

But with my caliper, here is what I came up with.  All are rough measurements.

Driver dia = 9.41 mm
driver + flange = 10.58 mm
flange measure by itself, depth = .62 mm
axle dis between 2 axles = 10.89 mm
axle dis from first to last driver = 44.48 mm

Hope that is somewhat useful.



 

[u18b]

All I know is that if he sent it to me, it would have gotten lost in the mail. That would be my story and I'm sticking to it.

Now that you posted this suggestion.... I don't think I could get away with it.   

[woodone]

Peteski- Yes I know that a lot of brass steamers have strung drivers, but I had not see any N scale steamers that had them.
I have two HO brass steamers apart (painting projects) right now. Each one has springs on the drivers. Like you, I think the springs are way too stiff. It takes a lot of pressure pressing down on the locomotive to make the springs compress. They might just as well mounted the drivers solid.  IMO. I might try some NWSL springs to correct.