Newer Atlas SD50 Drive Train Noise--Bearing Block Slop

[OldEastRR]

These people who complain about Atlas engines ... 

[busdriver]

I love Atlas cars and engines.  I have dozens of their engines, but for some reason, these SD50s are really hard to get to run smoothly.  Most of their models come out of the box like Swiss watches, but not these.  I bought 3 of them, and they all have the same issues.  However, they do run well when they are run together or with other engines or a train.  I think there is a lot of overall slop in the drivetrain which confuses the BEMF as the motor keeps loading and unloading with the slop when running alone.  That make it jerk around.  When the engine is sitting still on the track, I can move it by hand back and forth at least a mm or 2 before the drive train stops the movement.  That seems like a lot.  I just don't run any of them alone, and they are fine for me now.

Bryce

[peteski]

I love Atlas cars and engines.  I have dozens of their engines, but for some reason, these SD50s are really hard to get to run smoothly.  Most of their models come out of the box like Swiss watches, but not these. 

In my N scale world I reserve the "Swiss watch" comparison to Kato engines

While Atlas engines are decent, they are not close to the smoothness and quietness of Kato engines.  Funny thing is that earlier Atlas engines (in the '80s) were originally made by Kato (like the original RS-3 and RS-11), but then when the companies went their separate ways, Atlas basically cloned Kato low-friction trucks and flywheels design, however while Kato continues to use precision design and manufacturing processes, Atlas Chinese-made models aren't quite up to Kato's standard.  Also to me their "new and improved" redesign of the chassis and electric pickups is not all that improved.  But we all have our own standards.

[busdriver]

I have dozens of Kato engines as well, and I'm not quite sure I'm going to agree that Kato is better than Atlas.  I think I'm finding Atlas's detailing being better lately as well as slow speed operation being better in DCC.  Once I speed match an Atlas loco to my control set, it will behave consistently EVERY time I fire it up.  I have several that I use as DPU/helper engines on 75 car trains going up a 2+% grade with curves and will have no issue with the Atlas helper going the same consistent speed as the lead units.  However, I cannot say the same for my Kato engines.  I can have one running perfectly one day, and then it is a completely different speed the next day or even the next hour.  I would never think of using a Kato engine in DPU/helper service.  It is very strange to me that this happens since I will agree that they are very quiet and well built.  However, their slow speed smoothness and consistency is not the same as what I get out of my Atlas locos. 

Bryce

[peteski]

I agree that when it comes to shell details Kato is not up to par compared to most other brands. But that comes at the cost of using messy glue to tack on all those details (all of Kato shells are snapped together tightly with no glue, which again shows how well engineered they are). Paint finish quality is also superior in Katos, even if their color choices are sometimes questionable.  Atlas shells usually have rather thick layer of paint.  But color accuracy is a problem with all brands of models,

I was alluding specifically to your Swiss watch comment. That applies to the mechanical design.  As for the low-end speed, Atlas motors, while being Kato  clones have their rotors wound using different wire resulting in their low-speed motors, but with good  decoder with well tuned BEMF (or even DC throttle), Kato locos can have excellent low speed.  Not sure why you have problems with changeable running characteristics of your Katos- I have not experienced that.

As I mentioned, we all have different standards.  But when I have disassembled Kato (Japan) and Atlas (China) mechanisms laying side-by-side and I look at the overall quality of both, there is no comparison.  One could argue that I  am drinking the Kato Cool-Aid, but I clearly see the difference with my own eyes.

[busdriver]

Peteski,

I will concede that relative to my "Swiss Watch" comment, Kato wins.  I just wish Katos were more consistent runners for me.  But, I lash them in the middle of an 8 unit SP consist, and they will go along for the ride regardless of what they want to do at the moment.   

Bryce

[Mike C]

   @busdriver , Have you ever tried to put an Atlas motor into one of the Kato locos ?

[busdriver]

Hey Mike,

No, I haven't tried that. I have some spare Atlas motors, but they are reserved for old Atlas SD-9s that have the round-holed flywheels with the universal plastic that cracks, and there aren't any parts available any longer.  When they crack, a new motor goes in with the octagonally shaped drive shaft.

However, you now have me thinking about it........    Those motors aren't cheap these days.

Bryce