Kato BigBoy pic - large screen cap for detail

[robert3985]

Why isn't everybody clearly seeing 2 motors in that loco's cross section drawing, without any mechanical drive shaft between them?

The motors are blue, and light purple is metal chassis.  Lavender are the engine chassis'.  No connection form the back of the front engine motor to the rear engine's flywheel.  I do agree that the model is way overengineered, but Kato has been doing that to other models too.

As for rigidly mounting the rear engine, my N scale brass Sakatsu Big Boy is made that way.  The front engine's pivot point is also similar to 1:1 - it pivots at the rear of the front engine.  It needs wide curves to run.

Maybe they're color blind....

Cheerio!
Bob Gilmore

[reinhardtjh]

Why isn't everybody clearly seeing 2 motors in that loco's cross section drawing, without any mechanical drive shaft between them?

The motors are blue, and light purple is metal chassis.  Lavender are the engine chassis'.  No connection form the back of the front engine motor to the rear engine's flywheel.  I do agree that the model is way overengineered, but Kato has been doing that to other models too.

As for rigidly mounting the rear engine, my N scale brass Sakatsu Big Boy is made that way.  The front engine's pivot point is also similar to 1:1 - it pivots at the rear of the front engine.  It needs wide curves to run.

Maybe I'm off, mechanically, but to me, if the rear engine is rigidly connected to the boiler, then when going around curves, the front is going to swing out wide.  How does the worm and worm gear from the front motor - which is housed in the boiler - stay connected as the boiler swings back and forth on curves, turnouts, etc?  The curves would have to be extremely wide, wouldn't they?  I suppose a very wide worm gear might work, letting the worm slide back and forth across it.

[Sokramiketes]

So it was a rigged voting machine. 

I'm not sure about rigged, but with two Milwaukee Road models, voting got split allowing the Big Boy to win!

[sundowner]

Maybe I'm off, mechanically, but to me, if the rear engine is rigidly connected to the boiler, then when going around curves, the front is going to swing out wide.  How does the worm and worm gear from the front motor - which is housed in the boiler - stay connected as the boiler swings back and forth on curves, turnouts, etc?  The curves would have to be extremely wide, wouldn't they?  I suppose a very wide worm gear might work, letting the worm slide back and forth across it.

I think they are like the HO P42, the motors are truck mounted. It also looks like they found a way to keep the rear truck from swinging but still do fore to aft motion from the drawing.

[peteski]

Maybe I'm off, mechanically, but to me, if the rear engine is rigidly connected to the boiler, then when going around curves, the front is going to swing out wide.  How does the worm and worm gear from the front motor - which is housed in the boiler - stay connected as the boiler swings back and forth on curves, turnouts, etc?  The curves would have to be extremely wide, wouldn't they?  I suppose a very wide worm gear might work, letting the worm slide back and forth across it.

To  me it looks like the motor/flywheel unit is rigidly attached to each engine. Like a powered truck. The worm located between the motor and flywheels is coupled directly to the worm gear.  The pivot point for the entire powered engine is at the gear tower,  slightly behind the 3rd driver).  Both front and rear engines look identical.  I guess the rear engine might also swing (pivoting at the same location as the front engine, since they look identical).  That would make sense since these will be running on Unitrak curves, but what seems perfectly clear to me is that each engine is a complete powered unit.

Maybe they're color blind....

You might be onto something there Bob.  I guess I'm one of the lucky guys who can see a full color range. 

[ncbqguy]

I stand corrected.  Never having had a need for Challengers or Big Boys in plastic and certainly not in brass, I did not pay attention to the many brass examples shaft-powered to the rear driver of the front engine.   While these were mostly powered by one large motor on a common shaft, it did allow the rear engine to be fixed to the boiler.
This limits the operating radii well beyond most Unitrack curves and could be used with two motors but not for a non-brass production model.
 Charlie Vlk

[GhengisKong]

Official announcement next month according to them on facebook:

https://www.facebook.com/officialkatousainc/posts/pfbid02hu6NWRoFzVVAWXqKr5dEVERzKbV6zUJKAecSihbd9zmehRXj98XFKu3wX3mpgtm6l

[Ed Kapuscinski]

But when will there be an official official official announcement.

I swear, with all of the time they've spent on this they could've done a C30-7, C36-7, U28C, U30C, U33C and U36C...

[wcfn100]

But when will there be an official official official announcement.

I swear, with all of the time they've spent on this they could've done a C30-7, C36-7, U28C, U30C, U33C and U36C...

I was told the tooling time for this was the same as four diesels.

Jason

[sundowner]

https://katousa.com/n-bigboy/

[Scottl]

Wow, if I were ever to buy a steam locomotive, this would be the one I bought.  It looks fantastic.

[peteski]

Dual motors confirmed.
Model looks good.
The handrails look a bit chunky, but they are plastic so it would be difficult to make them thinner.

The write-up is not quite accurate. It states "Thanks to the articulated design just like the real engine, the two sets of driving wheels are able to move independently . . ."  That is not correct In the real 4-8-8-4 only the front engine pivoted (the pivot point was at the rear of the engine.  The rear engine was rigidly attached to the boiler.  But of course to negotiate 11" curves bot engines have to be articulated (just like other brands of Big Boy models).

And the pre-installed sound decoder will be Soundtraxx.  I find that odd, especially after ESU recently produced several decoders specifically for Kato models. But at least they do offer a DC version of the loco.

One thing that bugs me is that the plastic parts of the valve gear on all Kato steam locos use a silver plastic that has a "cool" silver color, which doe not match the "warmer" silver color of the metal parts.

Fleischmann for example also uses plastic parts for those items, but they use different mix of metallic powders in their plastic so the color better matches the rest of the metal parts of the valve gear.  I'm probably one of the few people who even notice this or care. 


EDIT:
I looked at the parts diagram. Very interesting design.  Each engine is a fully self contained unit, including the motor.  Sort of like the powered truck on their H0 P42.  Good to see that the weight of the engine is accurately balanced over the engines and that the traction tires are on the geared driver.

The tender looks like the one used with FEF.

[EspeeGoldenState]

Pardon me if I'm just merely looking at the diagrams too hard, but I dont see where the decoder(s) go in this thing.

Unless I'm missing something, as the tender looks just like the FEF did and empty. I'm assuming the green board on the Big Boy is the same relevance as the DC board for the FEF possibly? But that would make speakers a nightmare to run wires to. Maybe its going to be a hardwire? Seems so backwards.

FEF Diagram:
https://katousa.com/wp-content/uploads/2022/10/N-parts-FEF.pdf

Big Boy Diagram:
https://katousa.com/wp-content/uploads/2022/12/N-parts-BigBoy.pdf

[peteski]

Yes, I also don't see an easy way for a DCC conversion.  The motor leads connect directly to the frame halves of each engine, and I don't see any circuit boards in the tender.  The drawbar only has 2 conductors (for the rail pickup).  It would be strange if Kato didn't make those more DCC friendly.

[Jbub]

Pardon me if I'm just merely looking at the diagrams too hard, but I dont see where the decoder(s) go in this thing.

Unless I'm missing something, as the tender looks just like the FEF did and empty. I'm assuming the green board on the Big Boy is the same relevance as the DC board for the FEF possibly? But that would make speakers a nightmare to run wires to. Maybe its going to be a hardwire? Seems so backwards.

FEF Diagram:
https://katousa.com/wp-content/uploads/2022/10/N-parts-FEF.pdf

Big Boy Diagram:
https://katousa.com/wp-content/uploads/2022/12/N-parts-BigBoy.pdf

The green part is definitely a light board considering that the Big Boy's headlight sits on the pilot deck. As to where a drop in decoder goes, I can't tell from the diagram.