Athearn's Quiting

[sledgehammer]

I posted this question on the wrong frorum its been a long day.

I have a Athearns switcher that quits going down the track. It does quit at anytime or at any givin spot. I've cleaned all the wheel and contacts i seen. This is not DCC unit. The best part is the light will still work. The more you turned up the throttle the brighter the light gets. Any sugestions

[mcouvillion]

Sledgehammer,

I bet the contact on the bottom of the motor is no longer making contact with the frame. If it is not, your motor won't run. Carefully pu***he motor down into the frame and see if that helps. If not, carefully pull the motor out of the frame, bend the little tangs on the bottom of the motor out a little, and replace the motor. The tangs must contact the bare part of the frame under the motor. You're getting power to the engine because the light is bright, but it is essentially a separate circuit from the motor.

Let us know if this helps. If not, there may be a problem with the contact bar on top or the motor brushes, but this is the most likely problem.

Mark C.

[sledgehammer]

Mark
I looked at the loco and did what you said . I found two things. the motor does not want to stay all the way down. im thinking its jaring loose going around the track. Is there a way I can fix this. and the armature was dirty .

[cacole]

The biggest problem with Athearn locomotives seems to be related to the metal strap that runs across the top of the motor not making good contact with the metal brackets on the trucks.

A motor working loose is rare, unless it has been repeatedly removed for some reason. The motor is held in place by a nylon cinch on each side of the motor. Each cinch has two pins that push down into the frame. If the motor has been removed several times these pins may be worn.

One cure is to put a small amount of silicon sealant on the pins and on the bottom of the cinches as they are inserted into the frame and let it set for a couple of days before you run the engine so the silicon has a chance to set up. This will hold the motor down more firmly if that is your problem.

If you know how to solder, replace that metal strap with some very flexible wire so the motor gets better electrical contact with the trucks.

[mcouvillion]

Sledgehammer,

The white plastic holders on the bottom of the engine must be fully engaged to keep the motor down. If they are old and brittle, there is no way you can keep the motor down until you replace them. A good hobby shop should have them in stock and they are not expensive.

You can clean the armature if you carefully remove the motor brushes and brush springs. If you have never done this before, get a large plastic storage bag and perform this task inside the bag. The brush springs will get lost if you don't keep a close watch on them. Remove the brass clip from the top of the motor and underneath there is a small spring and then the motor brush. Do the same for the clip on the bottom of the motor. Place the brushes and springs aside. If you have a piece of sand paper with a grit number of 400 or higher, cut a strip about 4 inches long by the width of the armature, and then wrap the armature with the sandpaper to form a horseshoe with the sandpaper around the armature. Poli***he armature until it is bright and shiny. Take a sharp pin or the end of a hobby knife and clean the grooves between the five poles of the armature. Try not to scratch the polished surface. Next, move the armature back and forth along its axis in the motor frame. If there is too much play (more than 0.010"), you need to shim it. Take a Kadee shim (red - 0.015", gray - 0.010", don't use the plastic ones) and cut a Vee groove in one side. Slip the shim on the armature to take out the slack. The armature must still move freely. I lubricate the armature at the busings with transmission fluid at this point, and rotate the armature to make sure it is very free. Replace the brushes and springs, connect directly to a transformer with alligator clips, and run it in for a while. Vary the speed and direction until it sounds the same in both directions and you can turn the speed down and count the rotations. Re-install in the chassis. Have fun.

Mark C.

[sledgehammer]

Thanks mark will try this

[cwclark]

i had the same problem with a GP-35 and found that the small armature brushes (the cylindrical thing in the hole under the spring and the copper clips of the motor) was not making contact with the armature..i had to replace it with a new one (well actually an old one form another old athearn locomotive that didn't run anymore) and off it went...I had to break it in so that it would work by removing the drive shafts from the truck and with a very fine grit piece of sandpaper i let it drag on the armature while the motor was running ..i then used a pencil eraser to polish it , put it back together and it ran for a long time...now i'm going to have to go back into the engine again when i get a chance and check it out again..it's doing the same thing and it's the brush again i know it...chuck

[cwclark]

oh yeah!..also I had to rebuild the motor mounts that had rotted over the years..you can do this with two small pieces of sheet rubber mounted under the motor and against the frame to insulate it from the frame and then you will notice 4 small holes in the bottom of the motor...tap then out with a 2-56 tap and then run 2-56 screws into the motor from the bottom to hold the motor in place..you'll also have to install spacers so the screws won't move around..I used a very small piece of 3/8" styrene tubing placed over the 2-56 screws before running them home into the motor to hold them snuggly in place..the things we have to do to keep Athearn locomotives running!...oh brother!.....Chuck

[bbrant]

First off, I would adjust your timetables so the model crew inside the engine didn't hit the 12 hour limit. Sorry...baaaaaaad joke.

Seriously, and this was already mentioned, I would make sure that the metal bar going over the motor were still making the contacts at the end. Try running the unit with the shell off and see if you notice they lose contact when it stops.

Brian[:D][:D][:D][:D][:D]

[mcouvillion]

Sledgehammer,

One other thing, replace the metal clip across the top with wire. Scratch the surface of the top of the clip connector on each truck and then put some solder there. Use a heat sink (alligator clip) on the connector to keep the heat from transferring all the way to the plastic of the truck. Cut two small pieces of wire, one long enough to connect the two connectors with a little extra length for "play", and one from one connector to the top of the motor, the end near the brushes. Tin the ends of the wire and then heat them into the puddles of solder on the connector. The tinned end of the short wire will fit under the round end of the clip on the top of the motor if you carefully lift the clip ever so slightly. You don't have to solder to the motor clip. You will get much better electrical conductivity with this arrangement than with the metal clip. Use stranded wire of 18 - 20 AWG. It must be flexible. It could be a little smaller if necessary.

Polish your engine's wheels for better contact with the track. I usually chuck them in a drill press and use fine sandpaper strips to get them nice and shiny. Beats running them for years to get them to "wear in".

Good Luck.

Mark C.

[sledgehammer]

Thanks again fellow modelers. This is a very good site for information and you fellas amd ladies make it so. hopefuly someday I'll be able to answer your question.

[Anonymous]

hey bub, had same prob with 2 1975 D12's, its the top clip (the long metal bracket) touching the brass arms coming off the drive trucks need to be lightly cleaned with a ink eraser and the clip may need to be refitted to contacts. Let me know how it goes.

[Anonymous]

My geep was going to an old spring untill I replaced it, it was athrean.