N scale 4-8-4 driver sizes - measured

[kiwi_al]

Hi,
I can't find my Bachmann 4-8-4 Northern at the moment and was wondering if someone would mind measuring both the Bachmann 4-8-4 Northern drivers and  Kato GS4 or FEF 3 drivers to see if they are 80 inches like the real steam manufacturer or if they are smaller?

Thanks

Al

[PiperguyUMD]

If I remember correctly, the Bachmann 4-8-4 has 72" drivers measured over the tires. I can check for sure later today. They are definitely substantially smaller than 80". I used the Bachmann drive for my WM 4-8-4, which had 69" drivers.

[Jim Starbuck]

I don’t have a Kato GS4 but the FEF driver diameter is .4885 which scales to 78”.

Jim

[thomasjmdavis]

While folks are measuring.... I also have a 4-8-4 project on my to-do list.... could you measure the distance between the driver centers and/or center of first to center of 4th driver center?

My project is to do rough approximations of GTW 4-8-4s that had relatively short wheelbases.

[kiwi_al]

Cool, that's kinda what I was hoping for - really great information!!
I'll probably use the GS4 / FEF Kato driver set, i need close to 74 inches and no it's not for a 4-8-4 it's for a 2-10-4 

Thanks for the information, it's been really helpful.

[Cajonpassfan]

Cool, that's kinda what I was hoping for - really great information!!
I'll probably use the GS4 / FEF Kato driver set, i need close to 74 inches and no it's not for a 4-8-4 it's for a 2-10-4 

Thanks for the information, it's been really helpful.

Hmmm, that sounds like quite a project!
There was only one Texas type with 74” drivers, the AT&SF 5001/5011 class...is that it? That loco was a monster, and it had driver wheelbase of 26’-2”  and a total wheelbase of 50’-2”. IMHO, building a five-coupled locomotive using the Kato drivers will give you something much much bigger. Between the oversized drivers and the need for oversized flanges, it would be a SuperTexas with a wheelbase too long for anything but super wide  curves and long turnouts....YMMV.
Otto K.

[ncbqguy]

Don’t overlook the Micro-Ace JNR Pacific’s.   Since you need disc divers vs. spoked one of them might have drivers that are close to what you need.  You’ll need more than one to get the five sets of drivers but same is true for the Northerns.
Charlie Vlk

[kiwi_al]

Hi Otto,
Yes I'm looking at building the AT&SF 5001/5011 class 2-10-4. Yes it is big but it's not the biggest ATSF Steamer I'm building  .
The Kato drivers are 78" which is 4 inches over in diameter working out to 0.635 mm too big, so over 5 axles the increased length will be about 3mm which isn't a lot. If I go with the Bachmann 4-8-4 drivers they'll be 0.3mm too small in total about 1.5mm too small in driver wheelbase but nearer the prototypical measurements.
So from an ATSF modeller view I'm picking it would be better to use the Bachmann drivers instead of the Kato drivers?
I will need Super wide and super elevated curves for the project following this one 

@Charlie,
Yeah I had looked at the Micro Ace JNR Pacifics but I have more information on American Steam than Japanese prototypes, but I'll certainly have another look at them to see if I can get closer.

[Skeebo]

So, you gonna tackle the 2-10-10-2 then?

    Jim S

[kiwi_al]

  already started a long time ago but the mechanism kept tripping me up. I think I have that sorted now thanks to Maxs threads on his Steamers.

[Cajonpassfan]

Well, a 3000 class, that I want to see!
Two Bachmann 2-10-2’s?
Otto K.

[kiwi_al]

Well, a 3000 class, that I want to see!
Two Bachmann 2-10-2’s?
Otto K.

Yes a 3000 class and it'll be scratch built not using 2 Bachmann 2-10-2's because I want it to be reasonably accurate   I'll use a turtle back tender from ATSFnscalemodels - saves some work!!