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AHM Motor Problems??

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  • Member since
    February 2009
  • From: The banks of the St. Lawrence
  • 208 posts
AHM Motor Problems??
Posted by RailfanS on Tuesday, March 3, 2009 5:33 PM
Hello, I have had 2 AHM locomotives that belong to my friends in my possession for the last month and now they want them back. The only problem is that I had the locomotives because they needed repair but I still can't get the locomotives to work. One of the locomotives quit while I was cleaning the wheels, automatically causing the blame to be placed on me...Sign - Oops(Sorry). The other was brought to me with the motor completely bound up. I thought they would be simple fixes (just oil one and resoder a wire on the other). The one that was bound up is still bound up after trying everything I could think of, and the other just won't run. When I apply power both units spark for a few seconds around the brushes and then are unresponsive. Is this common in AHM motors? Is there a way to fix this? What could be causing the one motor to be binding so hard (I have a hard time turning it by hand)? Answers to any of these questions would be helpful. I have included a picture so you can see what type of motor I am talking about. The locomotive in the picture is the one with the bound motor, the other is an SD40 with dual flywheels. If it was up to me these engines wouldn't be worth the effort but it's not.(I took a picture with my digital camara but can't figure out how to insert it?) Please Help!!! 

Cape Vincent Southern Railroad

HO scale Horseshoe Curve in 5’x10’

My YouTube

  • Member since
    June 2005
  • 4,368 posts
Posted by Darth Santa Fe on Tuesday, March 3, 2009 6:19 PM

To post photos, you have to upload them to a photo hosting site (like Photobucket), and then copy and paste the photo link between [ img][ /img] brackets (remove spaces).

I know the SD40 motor looks like this:

Is that also what the other motor looks like?

I got an AHM FP45 a few years ago with the same motor as the SD40, and found that the brush springs had flattened and weren't putting any tension on the brushes. Stretching them out fixed the problem.

As for the binding motor, is the armature clearing the magnets? Are there too many washers on the ends of the armature? Is the motor case assembled straight?

Do the motors still draw current after stopping?

_________________________________________________________________

  • Member since
    March 2007
  • 2,751 posts
Posted by Allegheny2-6-6-6 on Tuesday, March 3, 2009 8:42 PM

I have a shelf full of those old clunkers, for the most part they are a simple as a brick, The first thing I would try is after removing the body shell clean where the brushes contact with a pencil eraser. Keep turning the flywheels by hand gently and rub briskly with the eraser. You'll see the armature get as shiny as a new penny. Thats because it was oxidized like old copper gets.. If that doesn't yield you immediate results check the contact of the brushes themselves. They very well may be burnt out.

I have to ask how did you clean the wheels and what with? One of the most common mistakes people make is over oiling the snot out of everything. By doing so you actually build a layer of insulation up between the wheel and the rails. The best thing I have found lately is electric contact cleaner, you can pick it up in Radio Shack for a few bucks.

As far as the bound up motor locomotive is concerned it needs to be dismantled step by step and examine everything as it comes apart to see weather the "binding" is something mechanical or just a case of a burnt out motor. I have seen pleanty of broken gears etc. so just about anything can happen. The weirdest things was a friend brought me one of his childhood AHM's that him and his dad used to run on their layout. I am not a model train mechanic or repairperson by any stretch of the imagination but he was literally begging me to see if I could fix the thing. After a couple of night I got around to taking a look at it and found melted right around the motor, it was fused into one solid rock. I called my friend and asked him what he tried clean it with, he replied Carburetor cleaner why? After I hung up I threw it right in the garbage after swapping the shell out with one of my old clunkers sitting on the shelf.

So be REALLY careful what you clean them with. Also do you have an exploded diagram of it? If not here is a link to where you can get one for it and any other vintage loco. Hope this helps


http://www.hoseeker.org/lit.html

Just my 2 cents worth, I spent the rest on trains. If you choked a Smurf what color would he turn?
  • Member since
    February 2009
  • From: The banks of the St. Lawrence
  • 208 posts
Posted by RailfanS on Wednesday, March 4, 2009 3:06 PM

Thanks for the tips, I haven't tryed anything else yet but when I do I'll let you know. When the SD40 died I was cleaning it with 91% Isopropyl Alcohol on a paper towel. I did this by placing one truck on the paper towel and putting power to the track. The locomotive ran fine for about 30 seconds before it appeared to "stall" like many engines do when you are cleaning them using this method (at least if your me). After I couldn't get it started I used the alcohol on a Q-tip to clean the wheels untill they shined. In both the locomotives the problem is not picking up the power. I did not oil the locomotive on the day I cleaned it ether.    

Cape Vincent Southern Railroad

HO scale Horseshoe Curve in 5’x10’

My YouTube

  • Member since
    March 2022
  • 1 posts
Posted by Bobby the Train Hunter on Friday, August 25, 2023 2:05 PM

Hello - This is  Bobby  from Bobby's Hobbies from the Train Hunter on Youtube -  I had the identical problem with a Lifelike/AHM C415 diesel in Rock Island  Colors.  The problem is this -  1) make sure there are 2 washers on top - tiny copper on top, plastic washer below and 2) Make sure that the curved metal magnet shields "snap" into the top fully - we are talking like 1/10,000 of an inch not fully snapped in, and the axle will BIND.  It should spin EASILY -  Figured it out today ! bothered me since 1970's !!!!!

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