Hi all. I just picked up an older atlas rs1 from their April 2003 production run. The locomotive is great. However, when running forward, the locomotive makes a loud humming noise. Like, really loud! However, in reverse, the noise is not there. It runs like a dream going backwards! Just normal motor and drivetrain noise.
The loco is DC, and I am using an MRC Tech two with the loco motion. I am not using the momentum switch.
I am planning on converting to dcc, so maybe the decoder will eliminate the noise? I have seen decoders with BEMF and silent running stuff virtually eliminate motor hum, but this is a bit of an extreme case.
Again, the noise is very loud, and only in one direction. The loco has zero run time. Lubrication is OK. So, the big question is, will the decoder eliminate the noise? Thoughts?
JJF
Prototypically modeling the Great Northern in Minnesota with just a hint of freelancing.
Yesterday is History.
Tomorrow is a Mystery.
But today is a Gift, that is why it is called the Present.
P.S. I will be installing an ESU loksound 5. Not Negotiable!
JDawg,
No, a decoder will not eliminate the noise. I would remove and clean out the old lubrication from the gears and lightly lubricate it with fresh Labelle 106. Given that the locomotive is nearly 20 years old, it could be a goop of dried lube in the gear cover.
The other thing you can do is remove the shell and see if 1) that eliminates the humming noise and/or 2) if you can locate the noise or find anything binding - e.g. wiring rubbing against the motor or flywheel.
Tom
https://tstage9.wixsite.com/nyc-modeling
Time...It marches on...without ever turning around to see if anyone is even keeping in step.
tstage JDawg, No, a decoder will not eliminate the noise. I would remove and clean out the old lubrication from the gears and lightly lubricate it with fresh Labelle 106. Given that the locomotive is nearly 20 years old, it could be a goop of dried lube in the gear cover. The other thing you can do is remove the shell and see if 1) that eliminates the humming noise and/or 2) if you can locate the noise or find anything binding - e.g. wiring rubbing against the motor or flywheel. Tom
When the drive goes the other way the 'other' thrust faces are fine.
Look also to see if anything pushes the motor shaft endwise at direction change.
My thoughts as well. The directionality suggests a slight misalignment or just poorer engineering/assembly that leaves the drive sloppy when the gears are meshing in one direction of revolution and not in the other.
With shell removed, and you impart the first speed step to the decoder (if it were DCC already), you'd probably notice a slight rearward or forward shift of the driveshaft couplings, if not even in the gear faces themselves, under good light. Or, it would happen with one or two quick revolutions of the gears as the locomotive accelerates from zero. In DC, you may have to abut the engine on the correct end to prevent it from moving, maybe hold it down a bit to increase traction X4+, and watch what happens as you increase voltage. Nothing long or hard so you don't break anything, just enough to see if you can pick up that slack or shift. Then you'll know where to apply the shim/spacer/washer, whatever makes sense AND THAT you'e prepared to trial AND undo...if needs must.
And wut Tom sez as well....those lubes gotta go.
Thanks guys. What I meant by the lubrication is ok is that I already did that. I may have missed something so I will double check the grease points.
Humbly, I think that the motor is likely the sole culprit. With the shell off, the noise is centered over the motor. If I had to replace it, where could I get one that's a good fit?
Okay, this may sound silly....
Nothing fouling or touching the motor brushes, right?
I had a unit that was flat out noisy, found there was something contacting the one motor brush, making the brush "off-center" by the tiniest bit. When corrected, she suddenly became very quiet.
It also still could be a "thrust" issue. That might create just enough force on one side of the motor to push it out of alignment by just a bit...
Flywheels clear? Even under power? I've seen drive-train play push a flywheel into the frame, creating a very definite rubbing noise, and only when under power in one direction. The other direction it did not push off enough for that flywhhel/frame contact.
If you think it's only the motor, and nothing else at all, an easy test would be to remove the drive shafts, and test only the motor itself.
If it still is noisy, it's purely the motor. If the noise disappears however, you must then look at the drive train.
While every manufacturer has a dud or two every now and again, a defective motor is not usually one of the issues from that new of a time period...
Ricky W.
HO scale Proto-freelancer.
My Railroad rules:
1: It's my railroad, my rules.
2: It's for having fun and enjoyment.
3: Any objections, consult above rules.
JDawgHumbly, I think that the motor is likely the sole culprit. With the shell off, the noise is centered over the motor. If I had to replace it, where could I get one that's a good fit?
Replacement motors are actually pretty easy to find on eBay.
I can't say for certain on your model, but motors from Genesis and Kato might be easy to fit.
Right now there are no Atlas motors listed that say they are specifically for an RS1, but there are lots of motors out there.
-Kevin
Living the dream.
Have you tried just doing a 'break in' run? Run the engine about 3/4 full speed for maybe 10-15 minutes going one direction, then 10-15 minutes the opposite. Surprising how much of a difference that can make on a new engine, let alone one that's been sitting for a couple of decades.
wjstixHave you tried just doing a 'break in' run? Run the engine about 3/4 full speed for maybe 10-15 minutes going one direction, then 10-15 minutes the opposite. Surprising how much of a difference that can make on a new engine, let alone one that's been sitting for a couple of decades.
Great advice!
I did not notice in the OPs post that this was a new (to him) locomotive.
A cleaning and break-in is certainly called for.
I'm still with the group saying that, while the motor might appear to be where the noise comes from, it's not the actual issue.
I base this on personal experiences and the fact the OP states that it occurs in only one direction.
If the motor was really the issue, one would think (logically) that it would occur no matter which direction the shaft is rotating.
Something is pushing something else out of alignment somewhere just slightly enough that it makes noise only when that is occurring, hense the only one direction issue.
Thanks for all the tips. I'll be trying them tonight.
Hello All,
Just in case...
Atlas HO RS-1 Motor/Flywheel Assembly; Item #885110
This might also help quiet motor noise, at a much lower price...
Hope this helps.
"Uhh...I didn’t know it was 'impossible' I just made it work...sorry"
It occurs to me that an el cheapo fix might be just reversing the motor block in the chassis and reconnecting slightly longer motor leads 'crossed'...
With the motor in the frame and shell off, use a feeler gauge between both flywheels and the motor frame in 'forward' and 'reverse'.
Check the brush fit by rotating the motor 'light' in both directions, then applying light pressure with a fingertip on each end of the rotating assembly. Does the motor make a similar 'hum' if you brake one of the flywheels lightly with a fingertip?
Recap for me what the amp draw is while all this is going on?
I would pull the wires off the DC CB if they are attached with those black slip on clips. (EDIT: But now that I think about it, is your DC board the gray one with the pickup wires stuck under stright wires?) Anyhow, then pop off the worm gear covers and switch the trucks around and see what happens with the hum noise. Is the noise still there going forward or is the noise there now going backwards?
Hi all. Welcome to story time with JDawg.
There once was a gorgeous RS1. It was so nice. The paint was wonderful, the headlights were bright, but the poor little loco had one flaw. It sounded like a freaking coffee grinder! I swear to...
Anyway. Jdawg wanted to help the little loco with its problem. But the loco did not want help. "I'm fine, I'm fine" it cried as it rolled backwards without a sound. But Jdawg knew better.
So he ripped apart the little loco to access its innards. But to Jdawg's surprise, the locos drive really was fine. Yet, he cleaned, lubed and helped little loco all he could. And the thing still sounded like a dog-on coffee grinder. As Jdawg prepared to punt the little loco out the window, he noticed a loose screw. He tightened the screw and the noise vanished.
Basicaly the motor was rocking against the frame which was causing the noise. The motor could only rock in one direction, meaning that it sounded like crap going forwards but fine in reverse.
I hope you enjoyed story time. Tune in next week for the case of the mysterious smoking loco!
so glad you got it fixed and shared the results!
JDawg I hope you enjoyed story time. Tune in next week for the case of the mysterious smoking loco!
I did. Ah, the belly screws.
For starters, I hope the mysterious ''Smoking'' loco has a smoke unit in it.
PC101 JDawg I hope you enjoyed story time. Tune in next week for the case of the mysterious smoking loco! I did. Ah, the belly screws. For starters, I hope the mysterious ''Smoking'' loco has a smoke unit in it.
Well, that's what makes it so fun. The smoke was a free extra!
JDawgAs Jdawg prepared to punt the little loco out the window, he noticed a loose screw. He tightened the screw and the noise vanished.
Rest assured you're not the only person on this forum to have a screw loose....
Oh, I love a happy ending!
However, "The Little Engine That Smoked" typically doesn't have a happy ending.
Thanks for the update.
In an ESU forum on another site someone was having motor buzzing issue (DCC already installed) Turned out to be the traction motor which could be eliminated in the funciton mapping and the buzz went away.
Henry
COB Potomac & Northern
Shenandoah Valley