Speaking of Shell Swaps...

[strummer]

...how about this one: will an Atlas China-built RS-1 shell fit a Kato-Atlas chassis?

(Assuming of course the truck-mounted couplers have already been removed from the A/K unit...)

Mark in Oregon

[peteski]

I'm curious as to why?
These Atlas Kato mechanisms were the old style design:  trucks weren't the low-friction design and there was not positive electrical contact between the truck and chassis. Plus IIRC, the worms were mounted directly on the long motor shafts instead of each worm riding in its own pear of bearings.  What I'm saying is that the RS1 mechanism is IMO superior to the older Atlas/Kato one.

[mecgp7]

None of mine (Kato made) have the worm on the shaft. They have the same set up as the latest releases. The worm is between two bearing blocks. The trucks are the weak point as Peteski noted.
That being said, the newer shell will fit the old chassis with one caveat. The side sills don't hang down past the edge of the chassis like the old one does. It is hardly noticeable and I painted the edge of the chassis which hides it well.

[u18b]

...how about this one: will an Atlas China-built RS-1 shell fit a Kato-Atlas chassis?

(Assuming of course the truck-mounted couplers have already been removed from the A/K unit...)

Mark in Oregon

Yes.  I have done it before.

Works perfectly.

[brokemoto]

I would second Peteski.   While I have not done the mechanical and electrical analysis that he has, my experience with both dictates that the China-built power chassis is the better performing of the two.   To be sure, I was never impressed with the performance of any Atlas/Kato until the SD-7/SD-9 appeared.   In fact, I would advance the argument that the Atlas/Kato SD-7/SD-9 is still one of the best operating N scale locomotives out there.  But, I stray.  My experience with the Atlas/Kato RS-1 power chassis has been that it is the least satisfactory of any of them, despite its having flywheels.   In fact, I had an Atlas/Kato RS-1 that performed its usual poorly.   As the particular road number was not on the Chinese-manufactured version, I bought a Chinese manufactured RS-1 and put the Atlas/Kato shell onto the mechanism.   For those who do want to do this, you must use the Chinese-manufactured railing assembly, but the Japanese-manufactured shell will go right onto the Chinese-manufactured railing module.  The whole business will then go onto the power chassis of Chinese manufacture.

[strummer]

Well, the only reason I ask is that I have an A/K unit, and there are so many nice Atlas shells available that I thought it might be fun to have a few on hand to swap out every now and then...

Once again, I find it interesting to hear how little regard there seems to be for the A/K units; I think I have close to a dozen of various types, and with the exception of my U25,(which I will ask about one of these days) all the rest run really well. As well, I think, as my China-built Atlas examples.

Seems I say this a lot on this forum, but "I guess I got lucky".

Mark in Oregon

[peteski]

There is nothing wrong with the Atlas/Kato models. In their day they were the best designed locos available. They also ran better than most other diesel loco models.  But their design was greatly surpassed when Kato modernized their mechanical design with the U30Cs  the low-friction trucks, positive-contact pickup strips and large flywheels made the older design obsolete.

Actually, the GP38-2s and F-units were a nice intermediate design step.  While those still used trucks similar to the older Atlas/Kato trucks, they had large flywheels and were made out of a very dense alloy (which improved the electrical contact. They also introduced large flywheels which allowed them to coast right through intermittent power pickup areas.

[Ron McF]

... the newer shell will fit the old chassis with one caveat. The side sills don't hang down past the edge of the chassis like the old one does. It is hardly noticeable and I painted the edge of the chassis which hides it well.

Yes.  I have done it before.

Works perfectly.

Thanks guys.  Like Mark, I have some of the older A-K units, but they don't get much run time in their current colours. So I've ordered some fancy new duds for them while Atlas has them on sale:
http://shop.atlasrr.com/d-199-n-rs-1-shell-sale.aspx.

Regards,
Ron