Atlas Gold SD-9 shell interchangeability

[signalmaintainer]

Are the body shells for Atlas Gold SD-9s interchangeable with the earlier versions? I'd like to acquire one but use an older, detailed shell.

[packers#1]

I’ve got an older painted GP38-2 shell and a sound GP38 and I believe everything is interchangeable; the only issue I ran into is the shell has the much older style light piping for the bulbs they used to use, so if I were to go to it permanently I’d need to swap the light pipes for the older shell to sit on the light board properly

[nickelplate759]

Not sure about recent production Atlas/China SD9s, but the original Atlas/Kato SD9 used a different body and had truck-mounted couplers.  That body doesn't fit well on the newer chassis, and the newer body doesn't fit at ALL on the Atlas/Kato chassis.

[jagged ben]

Pretty sure that if you're detailed shell is Atlas China (2004+) it will be just fine.

[signalmaintainer]

Pretty sure that if you're detailed shell is Atlas China (2004+) it will be just fine.

Thanks for the insight. I think you're right. I'm just visualizing the Gold Alco S-2 frame, which was so very different from anything else Atlas had done.

[spookshow]

The new chassis is completely redesigned (no longer split-frame, for starters).



The good news is that the shells are basically same as on the previous Chinese version. The only difference I can detect is that the arm on the piece of light-conducting plastic for the number boards and headlight is a little bit longer on the new version than it was on the previous version. Consequently, it won't work with the previous chassis (it gets hung up on the headlight bulb). So, if you want to swap shells, leave that particular piece with the model that it came from.

-Mark

[peteski]

Too bad Atlas chose to reinvent the chassis.  I still think the wire-free Kato-style split-frame with pickup strips in the chassis is the best overall chassis design, and easiest to service (for people like me who often take models apart)

[Sokramiketes]

Too bad Atlas chose to reinvent the chassis.  I still think the wire-free Kato-style split-frame with pickup strips in the chassis is the best overall chassis design, and easiest to service (for people like me who often take models apart)

I get it, but it's a bit more complicated than that.  Its the current factories that are no longer comfortably making the old designs. 

[peteski]

I get it, but it's a bit more complicated than that.  Its the current factories that are no longer comfortably making the old designs.

Comfortably?  What exactly does that mean?  What makes the old style chassis "uncomfortable"  (you know what I mean). 
Both designs require similar tooling, injection molding and stamping/machining.

Kato has no problems still  producing new models using the "old"design mechanisms, and they are even modifying them slightly  (like the screw-less design, which IMO makes things a bit more complicated, but at least it still follows the same design principles).

[Sokramiketes]

Comfortably?  What exactly does that mean?  What makes the old style chassis "uncomfortable"  (you know what I mean). 
Both designs require similar tooling, injection molding and stamping/machining.

Kato has no problems still  producing new models using the "old"design mechanisms, and they are even modifying them slightly  (like the screw-less design, which IMO makes things a bit more complicated, but at least it still follows the same design principles).

Similar processes yes, but not similar need for precision/tolerances.  Japan still gets it done. 

[peteski]

Similar processes yes, but not similar need for precision/tolerances.  Japan still gets it done.

Yup,  that's the problem with today's N scale models *NOT* made in Japan.  I rest my case.

But the curiosity in me also wants to ask "which tolerances" and why the new design is more forgiving to looser tolerances?
Bachmann has been making (and selling) mediocre split-frame models (in Hong Kong I believe even before before Kato made theirs.

Ever since the Chines knockoffs of Kato's design started to be manufactured in China (for Atlas and others) I have noticed that the parts used in those models were not as good quality or finish as Kato's version, but they still worked well.  There are likely hundreds of thousands of those knockoff mechanisms out there (Atlas, Life-like and others) made over last few decades and they all seem to be functioning satisfactorily, even with their inferior quality.

Are you saying that those Chinese factories are getting sloppier and sloppier (instead of going in the opposite direction)? Not sure if I buy that either.

Anyway, our discussion has gotten off-topic, and none of this is really related to the original questions. 

[signalmaintainer]

The new chassis is completely redesigned (no longer split-frame, for starters).



The good news is that the shells are basically same as on the previous Chinese version. The only difference I can detect is that the arm on the piece of light-conducting plastic for the number boards and headlight is a little bit longer on the new version than it was on the previous version. Consequently, it won't work with the previous chassis (it gets hung up on the headlight bulb). So, if you want to swap shells, leave that particular piece with the model that it came from.

-Mark

Thanks, Mark. You always have the good info.

[Peachymike]

Yup,  that's the problem with today's N scale models *NOT* made in Japan.  I rest my case.

But the curiosity in me also wants to ask "which tolerances" and why the new design is more forgiving to looser tolerances?
Bachmann has been making (and selling) mediocre split-frame models (in Hong Kong I believe even before before Kato made theirs.

Ever since the Chines knockoffs of Kato's design started to be manufactured in China (for Atlas and others) I have noticed that the parts used in those models were not as good quality or finish as Kato's version, but they still worked well.  There are likely hundreds of thousands of those knockoff mechanisms out there (Atlas, Life-like and others) made over last few decades and they all seem to be functioning satisfactorily, even with their inferior quality.

Are you saying that those Chinese factories are getting sloppier and sloppier (instead of going in the opposite direction)? Not sure if I buy that either.

Anyway, our discussion has gotten off-topic, and none of this is really related to the original questions. 

A bit off topic but good information. Change for improvement is not always successful. The Kato design is well thought out, well engineered using quality materials and process. There are very few if any that can equal all those traits. Unfortunately the modellers and our dollars end up being the proving grounds for these design changes.

[AllTrac]

I am a new N scale modeler and also would like to swap shells on a couple SD's. I have a new SP DCC and sound and a older UP with factory DCC. I was able to remove the shells and fuel tank but hit a roadblock with the trucks. The older UP trucks pop in and out but the new SP trucks seem to be "hard-wired". The UP trucks are silver and the SP's are a grey. Can I swap just the truck side frames and if so what is a safe way to do so?

Thanks in advance.

-Dave

[Wolf N Works]

Side frames should just swap