I think its mainly the gaps in the motor commutator causing the edge of the brushes to slap into them. People have filled the gaps with epoxy and have reported a large reduction in growl.
- Douglas
I remember having BB units and finding that vibration of the drive train was amplified into noise by the contact of the metal frame and the plastic body. Applying a sound deadening material to the inside of the body and where it made contact on the frame made one heck of a difference in noise reduction. It's been 30 years since my last BB left the roster but if I recall correctly the frame received a brush-on rubber type insulation any place it touched the body, while a rubber tape was used to line the inside of the shell.
I've had mixed results quieting down Athearn BBs. I will shim the idler gear with KD washers and I use thrust washers to take up slack on the worm gear and the motor armature. I don't worry about removing the armature to add thrust washers...the shimmed up motor seems to be as good as new. I think thesintered ceramic magnets don't lose much, if anything, when the armature is removed.
Those old sintered metal wheels can be substantially improved by chucking each 1/2 axle and wheel into a bench top drill press and using mag wheel polish on them with a soft sponge. There is a You Tube video on this procedure but I have used it on BB wheels and the shiny smooth result cuts noise and improves electrical contact. Not to mention the wheels stay cleaner and so does the track. A jar of Mothers or similar polish and a regular cellulose sponge goes a long way at a low cost if you don't want to spend on replacing the sintered iron wheels!
Cedarwoodron
Much of the noise from Blue Box locomotives comes from tiny bits of flash or other crud in the gear drives. As each bit of crud goes thru the gears it makes noise. I quieted a pair of F units down by merely taking the gear towers apart, cleaning all the grease out of them and then wiping each tooth of every gear with a pipe cleaner. Each time the pipe cleaner would come up with a few tiny bits of black flash, almost invisible against the black plastic of the gear towers. Re assembly with just a touch of grease (I use white molly grease from the auto parts store) and the A-A pair of F units ran a good deal quieter.
David Starr www.newsnorthwoods.blogspot.com
I read somewhere that vaseline is helpful for lubing athearn BB's...
I'm beginning to realize that Windows 10 and sound decoders have a lot in common. There are so many things you have to change in order to get them to work the way you want.
How much do the bodies have to do with the noise? When I have taken them off of any of the ones I have, the engine is fairly quiet, put the body on and they are noisy. Can anything be done with the bodies or are they not a big player in this?
RR_Mel Unless I’ve just been very lucky the only thing I’ve ever had to do an Athearn BB was fill the ball joints with Lubriplate. That has always taken care of the noise. I have dozens of BB locomotives all run perfect with very little noise. Mel My Model Railroad http://melvineperry.blogspot.com/ Bakersfield, California I'm beginning to realize that aging is not for wimps.
You must be lucky - I've never witnessed (without reworking) a quiet BB engine. My experiment netted a perfectly quiet engine. Even with my ear right up to it, there was absolutely no noise of any kind - perfectly silent as it glided along. I am adamant about this with my own engines, even the slightest noise annoys me and it's off to the bench for a re-build.
Mark.
¡ uʍop ǝpısdn sı ǝɹnʇɐuƃıs ʎɯ 'dlǝɥ
Mark gives a great analysis and good advice.
.
Of all the steps, all I do is replace the wheels. I used the newer Athearn wheel/axle/busing/gear assemblies on my PA-1s, and it made a great difference, and so much easier than installing NWSL wheels.
If they get too loud, I simply turn up the music.
-Kevin
Living the dream.
My experience with them revealed a number of items that contributed to the noise ....
1. - Brushes rubbing on the large commutator create a singing sound. I've filled the slots in the commutor with expoxy and turned the commutor smooth after it hardened - noise gone.
2. - The armature shaft isn't 100% true. Any slight wobbly in the shaft will cause a vibration noise within the bronze bushings at either end of the motor case. Start with a perfectly true armature shaft for a perfect re-build. My experience has been more than half out of a lot are NOT true.
3. - Multiple drive shaft connectors. All those balls / cups / sliding shafts all have a slightly loose tolerance each on there own. Altogether, they add up to quite a bit of drive-line chatter. My answer here is to tighten the tolerance without deletig the flexibility. I accomplish that by disassembling every component and make sure it is clean of any lubricants. I then brush on a thin coating of silicone to the ends of every part and re-assemble. Align the trucks so they are straight and let cure over night. Once set, the silicone has taken up any tolerance, yet is still flixible enough to turn and rock. - noise gone.
4. - The brass worm gear is also a noise source. Replace it with a delrin worm gear from a newer Athearn engine. - noise gone.
5. - Truck gear slop. I use the thin Kadee truck washers on each individual gear to take up and side-to-side gear slop. You want them snug, not tight. I also pack the gear case with a heavy gear case grease. It must be a good quality grease that won't break down over time and leach out of the case. - noise gone.
6. - Wheels. Those old Athearn sintered iron wheels not only get dirty easy and loose contact, the are also noisy on the rail. Replace them with a set of nickel silver wheels. Smoother and quieter, they also provide better contact. - noise gone.
After all these processes done to an old Athearn BB of my own, I did a comparison test to an Atlas U23B. The rebuilt BB was quieter that the Atlas engine and actually drew less current across the board under different loads.
Was all this effort worth it ? .... probably not. I just wanted to take it upon myself to prove that an old Athean BB was capable of more than it was .... and ultimately, it was.
Hi,
I've had a lot of these "back when" and they were a great buy at that time. The noise is a combination of gears (esp. in the trucks) and the motor itself. They have a brush/commutator motor which by its nature will make some noise. All said however, with some lubing and a bit of tuning like cleaning up any debris in the gears or frayed cogs, etc. I would also take the motor apart (not sure if you can do it to all) and clean up as well.
Mr. Irv Athearn's "Blue Box" locos and rolling stock started many of us off on a life long hobby, and it is notable that many of his creations are still on a lot of layouts. ENJOY !!!
ENJOY !
Mobilman44
Living in southeast Texas, formerly modeling the "postwar" Santa Fe and Illinois Central
Picked up a used Blue box the other day for a real good price. I know they are noisy by todays standards but lubed it and that did tone it down. Would someone refresh my memory, what makes them noisy? Is it the gears, body or both. Seems I remember many years ago guys used to put pearl drops on the gears and it would quiet it down. This loco is going to be used for slow switching so the noise is not a problem but was just wondering where it came from, I couldn't remember.
Bruce