Recent Atlas Loco Production - "Old" Wheel Profiles

[C855B]

All in good fun, Frank @amato1969 was bustin' my chops a little bit over my whining about the new-release GP30s chattering on Micro Engineering Code 40 track. Easy enough to replace wheelsets with Kato parts like I've been doing with my older production Atlas (and Kato). However, it occurred to me that I haven't needed to do this to other semi-recent Atlas. For example, the S-2 released two or three years ago is fine on C40 (and a helluva great runner!... but I digress...).

So I checked the recent-release C630s in the fleet. Oops, same problem, chatter on C40, and flangeways on Atlas C55 crossings don't quite clear. Close, but there's interference nonetheless. For discussion's sake, the problem Atlas wheels have 0.027" flanges, while Kato comes in at 0.017" (measurements +/-0.002" or so). That's a significant difference.

Long story short, the newest loco wheelsets don't pass the NMRA gauge. Wheel width is too wide; flanges are too deep and bottom out in the template. Checking against old Atlas wheelsets in the junkbox, whaddayaknow, the newest wheels match those profiles. Did somebody at Atlas have a big "Oops!" and send old wheelsets to the new factory to use as patterns?

[wazzou]

...Checking against old Atlas wheelsets in the junkbox, whaddayaknow, the newest wheels match those profiles. Did somebody at Atlas have a big "Oops!" and send old wheelsets to the new factory to use as patterns?

Quite disappointing if that's the case.

[peteski]

That is a step backwards!
I also suspect that the S2 was made by another factory, since its overall design and even the wheels were so different from the typical Atlas design.

Do the new ones still have that toy-like wheel face?

[C855B]

Yep, sure do. That's why I suspect an "oops":

[narrowminded]

Yep, sure do. That's why I suspect an "oops":

Could it be Atlas just had a "happy accident"?

[dem34]

Could it be Atlas just had a "happy accident"?

wow bob, look at all these spare wheel sets.

[peteski]

Yep, sure do. That's why I suspect an "oops":

Mike, yes, the face profile seems similar, but those are made in a totally different way.  Compare them to the old ones  in my photo.  There seems to be a plastic sleeve around the half-axle!!  Why would they do that, since the half axle needs to be in contact with the wheel (not insulated from it).  What does the center part of the wheelset look like. But these aren't just copies of the old wheelsets - they are different!

[peteski]

wow bob, look at all these spare wheel sets.

Yeah!  All those wheesets were removed from Atlas locos, and replaced with modified Kato wheelsets.  But I don't throw stuff away - they might come in handy for something . . . 

[Tom L]

Yeah!  All those wheesets were removed from Atlas locos, and replaced with modified Kato wheelsets.  But I don't throw stuff away - they might come in handy for something . . . 

You could sell them back to Atlas!

Tom L

[Cajonpassfan]

Frustrating and disappointing. Going backwards.
Somebody always has to reinvent the wheel
Otto L.

[C855B]

...Somebody always has to reinvent the wheel

You, sir, shall suffer mightily for that.   

[Steveruger45]

Yeah!  All those wheesets were removed from Atlas locos, and replaced with modified Kato wheelsets.  But I don't throw stuff away - they might come in handy for something . . . 

Flat car loads, suitably weathered perhaps.

[peteski]

Seriously guys (Mike?), I'm curious about the construction of those new (crappy) wheels. Can anybody shed some light why they have what looks like a plastic  insulating collar between the wheel and the axle?!  The wheel is supposed to be in contact with the axle.  How do these pick up electricity if the wheels are insulated? 

[C855B]

I only have an iPhone for these macro shots, so shadowing in the wheelset shot made the center insert look dark since it was slightly inset. Here's a backside pic:



Definitely metal, but definitely an insert and not a machined collar on the axle. Three pieces. Why?

[peteski]

I only have an iPhone for these macro shots, so shadowing in the wheelset shot made the center insert look dark since it was slightly inset. Here's a backside pic:



Definitely metal, but definitely an insert and not a machined collar on the axle. Three pieces. Why?

That's weird!  Why is this so overcomplicated/overengineered now!?  Who approved this new design?    So what looks like plastic sleeve is actually blackened metal?
It is not a part of the half-axle?  Is the half-axle still made from steel?  Are you sure that the collar and half axle are not a single machined piece?

The older (and much simpler) design just used a a machined wheels with a half-axle made from stainless steel rod pressed into it. What possible advantage can the current design offer over the old design?  It seems to be more complex with not good reason I can see for changing the design.