Noisy Atlas RS1

[cholmes]

I have a perplexing problem with an Atlas RS1 that I just purchased.  The engine with its original body shell runs smoothly and very quietly.  I recently tried replacing the original body shell with another pre-painted RS1 shell from Atlas.  The engine now has a very noticeable buzz when it runs although it still runs very smoothly.  Has anyone come across a problem like this and found a solution?

[mecgp7]

It can be a few things. When swapping the shell, you may have squeezed the frame halves tighter together which can affect the motor noise. Another possibility is the second shell may not be tightly connected to the sidesill which allows it to vibrate and make noise. I've had success with a rubber type cement between shell connections to prevent vibration.
Of all the Atlas locos, the newer release RS1s and 3s have been most problematic for me in terms of noise. I've removed the inner bearing block on most if not all ( the Beardon procedure).

[u18b]

You didn't mention if the trucks say made in Japan (Kato) or made in China.

China is better.

If you have not removed the inner bearing blocks, you should take a look at my tutorial.

http://u18b.com/tutorials/

It really works.

[DKS]

Try swapping the shells back again. If the noise continues, it's likely that something was inadvertently done to the mechanism during the swap. If it's not noisy any more, then it's something unique about the new shell.

[mmagliaro]

I agree with DKS, put the old shell back and see if the noise goes away.  Run it without the shell as well.

I had this very problem with an RS1.  I bought it from somebody else who had swapped the shell, and it
ran with lots of noise, but quite smoothly.  One of the two motor "doughnut" mounts
had come off the motor, so the engine ran seemingly
fine, but sounded like a coffee grinder.  I was surprised that it even held together and ran as well as it did
with a dislodged motor mount.

[cholmes]

I want to thank everyone who suggested ideas for reducing the noise from my RS1.  I glued the walkway and  handrail sets together but that made little difference except to make removing the shell easier.  I ran the mechanism alone and it ran quietly and smoothly.  I swapped shells and didn’t notice any change so I narrowed the problem down to the shell.  I took Bob Horn’s suggestion and glued small pieces of 0.005 styrene above and below each of the flywheels on both sides.  I used cyanopoxy because I’ve found it to be stronger than regular super glue.  I then lightly sanded the inside of shell opposite the motor and flywheels.  The noise has been drastically reduced.  It is still not as silent as my LifeLike FA1 but the noise now is barely noticeable. 

[mecgp7]

Thanks for the update. Sounds like you got some great advice. Now it is your turn! I don't quite understand what you did. Any chance you could post some pics or spell it out a little better for me? Sorry, I can be a little slow

[central.vermont]

You know I just did a decoder install in an RS1 today. I put the TCS CN decoder in it. I had test ran it for several minutes on the layout before installing the decoder just to see how it ran before doing the install. It ran very nice and quite. Did the install and put it all back together and thought I was very careful not to get the motor doughnuts miss aligned. Ran just fine until I put the shell on and WOW!!! What a noise!!!! So I took it apart and looked at the doughnuts and sure enough one of them was reversed. Now the question was which one was right. Well as you would know I reversed the wrong one around and the noise was just as bad. So I changed them around to face the other way and it ran just as quiet as before.
So you ask what was the right way. I'll do my best to describe this. If you look at the doughnut you will notice that one side has little fingers on it that are springy and the other side is solid. I found that if you install all the drive parts and motor in the frame half that the bearing blocks sit in that half should have the SOLID side of the doughnuts facing it. Now the other frame half has the little brass springy fingers on it will have the springy fingers of the doughnut facing it.

Hope this makes sense and helps out others out there but the timing was just right for this to happen to me with this discussion going on.

Jon

[Bob Horn]

Jon, you are on the wrong end of the problem. The donuts are on the ends of the motor, the brass parts are at the worm bearing locaters. Bob.

[central.vermont]

Bob,
I think you missed the point. Yes the brass parts are worm locators but the doughnuts have plastic locators. You need to make sure all these locators are pressing the drive line parts in the same direction. The plastic doughnuts are motor locators and if anyone of them are facing the wrong direction it will twist the motor and cause  the flywheels to touch the shell on the inside causing the noise.

Jon

[peteski]

John, as long as both motor mount springy tabs face the same direction, I don't think that it matters whether those springy tabs face the left or right side.  The parts diagram on the Atlas website does not show enough detail to see which way they are assembled at the factory.

[cholmes]

I would gladly share a photo of the mechanism but the "inseert image" command doesn't seem to work.  I have posted a photo on two other forums.