Atlas/Kato RSD 12

[u18b]

Not sure what all is going on with yours.....

But here is mine.  A 31 year old RS-3.

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Not as quiet as a new Atlas CW40-8 or a Kato E8, but still pretty good by my standards.

[wm3798]

Isn't the RSD a 6 axle?  Seems to me the problem is in the fact that all three axles in each truck are geared, and the gears were either fragile or prone to binding.

I think in the later version made for Atlas in China, only two of the axles are geared and the third is an idler.  Spookshow could verify this for us.

Lee

[brokemoto]

Lee would be correct.  The A/K RSD-4 has all six axles geared.  The one that I had ran better than the GP-7s, GP-9s, RS-3s and RS-11s that I had.

The Chinese version has only two of the axles geared.  I forget if it is the inners or outers.  I would have to go upstairs and look.  The Chinese version is not the best puller.  In fact, the Chinese RS-3 is a better puller.  Another funny thing about the Chinese RSD-4 is that if you put a pair at the head of a train, two will pull better than double the number of cars that one will pull.

Funny thing, the Kato RSC-2, unlike the prototype, has all six axles geared.  It is a pretty good puller.

[rschaffter]

Since you have it apart, burnishing the frame bottom where the trucks contact it, and the trucks where they contact the frame with a steel rod or the flat of a smooth screwdriver will improve electrical pickup...

[peteski]

Since you have it apart, burnishing the frame bottom where the trucks contact it, and the trucks where they contact the frame with a steel rod or the flat of a smooth screwdriver will improve electrical pickup...

I go one step further. I use a multi-grit finger nail polishing board to get it almost polished, then finish the polishing process with a felt wheel in a Dremel and some polishing compound.  The pads end up mirror-smooth.  The polishing compound also inhibits oxidation.

[Power Stroke]

The center axle of the RSD is geared to mesh with the worm, it also has a molded second gear which drives the other 2 axles. The axles are split so that wheel flange width can be adjusted. As I explained to Ron in a PM a few days ago, the front truck was the source of all the racket and binding.
The gears are in perfect order with absolutely no damage, and the gear can not be installed backwards, as it would not mesh with or drive the remaining axles. What fixed the issue was adjusting the wheel flanges on only that axle to the narrow end of the spectrum.
In other words, the flanges are sitting at the top of the notches on the NMRA gauge. All other axles are adjusted to the center of the notches.
It now is quiet, both trucks operate, and it pulls at least 12 cars around my layout which is anything but flat.
Don't ask me why but there it is.
Thanks for the input.

[peteski]

So, re-gauging wheels of the center axle fixed the noise problem?

Do you have any idea what exactly was generating the extra noise when the gauge was out of spec?  Is it possible that you taking the truck apart and reassembling it fixed some other problem too?  I assume that is what you did.

[Power Stroke]

So, re-gauging wheels of the center axle fixed the noise problem?

Do you have any idea what exactly was generating the extra noise when the gauge was out of spec?  Is it possible that you taking the truck apart and reassembling it fixed some other problem too?  I assume that is what you did.

Pete.
The noise and binding were happening when the center axle wheel flanges were in spec. They are now set slightly narrow.
Yes, I had everything apart, and no issues were found. I only tried narrowing the wheels as a last ditch effort to shut it up, and it worked. If I adjust back
to spec, the noise and bind comes right back. I have absolutely no idea why.
Like I said, wheel flanges on all other axles are set to NMRA spec.

[rodsup9000]

I have absolutely no idea why.

 When you slide one of the wheels out to get it spaced right, the gear isn't alined right. Why don't you see which wheel half is moving out when you put it in gauge. Try running it and if the noise is back, move the that wheel half back in and try moving the other wheel half out of the gear.  I,m lost if that doesn't work.

Rodney

[peteski]

When you slide one of the wheels out to get it spaced right, the gear isn't alined right. Why don't you see which wheel half is moving out when you put it in gauge. Try running it and if the noise is back, move the that wheel half back in and try moving the other wheel half out of the gear.  I,m lost if that doesn't work.

Rodney

Very good idea Rodney.