The Magic of Kato Wheels

[Angus Shops]

To my eye, the superiority is obvious.  The Kato wheels have a more rounded-over flange edge, and the flanges themselves slope out gently to the wheel tread.  The Atlas flanges are more like a "pizza cutter blade", which would make them more susceptible to picking points and frogs.
Thanks for the photos.

Oh, this explains a lot. For a while (until I did a bunch of adjustments to my Fastracks jig built switches) I had an issue with my Atlas GP 7/9’s getting jammed up in said switches when every other brand of loco in my fleet (mostly Kato and Intermountain F units) slid through the switches without complaint. The solution was to adjust the point rails to give a smidge more space between the open point rail and the stock rail. The problem seems pretty clear in the close-up comparison image of the two brands of wheel sets. This was frustrating until I’d modified the offending switches, but I also agree that Atlas wheel sets are more prone to picking up ‘rail crud’ than Kato wheelsets.

[Ed Kapuscinski]

Did you do the 0.01" (or something similar, I don't remember) modification to them before swapping?  Or did you do a straight swap?

I have a set of those that I've been wanting "one of these days" to put in an Atlas SD50 because the wheels brass'ed out.  What's stopping me is the extra work of axle length modification that Peteski documented fully in another thread.

Since you didn't mention any axle adjustments I was just wondering...

Nope, direct swap.

Keep in mind, on the Atlas truck design, the axle length really doesn't matter much. As long as you get good contact with the contacts, you're good to go.

[peteski]

Nope, direct swap.

Keep in mind, on the Atlas truck design, the axle length really doesn't matter much. As long as you get good contact with the contacts, you're good to go.

Well, not quite.  Kato wheelsets have axle length longer than Atlas. That results in a excessively tight fit inside the bearing cups.  While you might think that will result in even better electrical connectivity (that is probably true), it will result in increased friction and early wear of the bearing cups.

I like things to be just right (not kludged) and I highly recommend modifying Kato axle length.  It's really not difficult. While I have an arbor press, there are examples of simpler tools that can do the job. Once you fabricate a simple fixture (piece of certain thickness material with a hole to limit the movement of the ram pressing the axle) to make the procedure repeatable, the process is super simple and quick.

Come on @MK , you have more than ample skills to do that.    You were actively involved in the thread I pointed to in my earlier post. Get off your a$$ and just do it right!
https://www.therailwire.net/forum/index.php?topic=33107.msg596617#msg596617
https://www.therailwire.net/forum/index.php?topic=33107.msg625244#msg625244
https://www.therailwire.net/forum/index.php?topic=33107.msg625256#msg625256

[MK]

Come on @MK , you have more than ample skills to do that.    You were actively involved in the thread I pointed to in my earlier post. Get off your a$$ and just do it right!
https://www.therailwire.net/forum/index.php?topic=33107.msg596617#msg596617
https://www.therailwire.net/forum/index.php?topic=33107.msg625244#msg625244
https://www.therailwire.net/forum/index.php?topic=33107.msg625256#msg625256

    I was indeed!  Too much traveling and too little project work!     Then again I ride all these nice beautiful trains in Japan and then go to the hobby stores to pick up an N-Scale set of the same.  Easy Peasey!   

I don't have an easily accessible arbor press.  But I do have a bench drill press that I can substitute for that.  Have to figure out where to get thin materials for spacers.  I'll have to starting mic'ing old credit cards and the like.