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causes of motor noise?

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  • Member since
    July 2009
  • From: lavale, md
  • 4,640 posts
causes of motor noise?
Posted by gregc on Saturday, December 29, 2018 10:29 AM

in the other thread i mentioned that I have a boxcab and Gem Rdg B8 0-6-0 with vertically mounted open frame motors and metal gear and worms.   The boxcab is very quiet while the 0-6-0 growls.

however, i noticed that if I prevents the 0-6-0 from moving, wheels spinning, it is quiet.

i'll guess this loads up the motor mounts preventing them from moving/vibrating.

is the the cause of motor noise vibration between the motor and frame and any slop between the gear/worm?

would a plastic work or gear prevent this?

is there any trick to determine how tight the worm/gear should be?

greg - Philadelphia & Reading / Reading

  • Member since
    January 2009
  • From: Bakersfield, CA 93308
  • 6,526 posts
Posted by RR_Mel on Saturday, December 29, 2018 10:46 AM

I have several older steam locomotives with open frame (Pitman DC-70 and 71) motors and all the motors run very quite.  Some have a lot of rod noise, a paste type lubricant normally reduces the rod noise.  All of my open frame motor locomotives have screws to adjust the worm to gear clearance.  I normally adjust the worm so that it just clears the gear by maybe .008” to .01”.
 
I had one open frame motor that rattled and tightening the magnet screw took care of the rattle.
 
Mel
 
 
My Model Railroad   
 
Bakersfield, California
 
I'm beginning to realize that aging is not for wimps.
 
  • Member since
    December 2004
  • From: Bedford, MA, USA
  • 21,334 posts
Posted by MisterBeasley on Saturday, December 29, 2018 11:05 AM

Old Athearn belt drive engines were very quiet, while their geared engines were known as "grinders" for the noise.  From this I conclude that it's the gear towers making all the noise, even when the gears are plastic.

I tried running an engine with Pearl Drops to quiet it down, but it didn't make much difference.

It takes an iron man to play with a toy iron horse. 

  • Member since
    May 2004
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Posted by 7j43k on Saturday, December 29, 2018 11:11 AM

RR_Mel

All of my open frame motor locomotives have screws to adjust the worm to gear clearance.  I normally adjust the worm so that it just clears the gear by maybe .008” to .01”.
 

 

If'n you don't have adjusting screws, you might try shims.

 

Ed

  • Member since
    March 2002
  • From: Milwaukee WI (Fox Point)
  • 11,427 posts
Posted by dknelson on Saturday, December 29, 2018 11:47 AM

Some cheaper motors of the open frame sort did "chatter" if the commutators were not properly turned on a lathe to be even.  But we are talking really cheap/bad motors here.  And some squeaked a bit if bearings were not lubricated.

The growl on the die cast steam locomotives I had was almost always a result of the motor mount causing the worm to not mesh ideally with the gear on the wheel due to distance or angle.  Removing the motor and letting it run "solo" proved this.  

Sometimes all it took was a sheet of bond paper between the worm and gear, then tightening the motor to the frame, and slowly/carefully removing the paper by hand turning the worm to free up the tight mesh of the gears, but this took tinkering.

Dave Nelson 

  • Member since
    February 2005
  • From: Vancouver Island, BC
  • 23,321 posts
Posted by selector on Saturday, December 29, 2018 12:01 PM

There's a difference between causes of noises and where they are actually emitted.  For example, while a shaft bearing or gear alignment might be off enough to cause chatter and vibrations, it might actually be their tower or mounting, or nearby surfaces, that actually emit the sound we're capable of hearing.  Doesn't really matter, though, in the cure; you have to fix the problem, and the noise will take care of itself.

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