# AF 312 help



## hjstr6 (Jul 12, 2019)

Hope everyone is safe and well.

I recently began refurbishing an American flyer 312 locomotive that I purchased in a lot a while ago. I believe this 312 is from 1949. The fourth digit on the stamp inside the boiler is smudged so I'm not positive the exact date. The numbering on the cab appears to be a silver stamp 312. I am not sure.












It may be a dry transfer but I am not sure. Wondering whether a dry transfer is available.


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## AmFlyer (Mar 16, 2012)

Based on the brass coupler weight it is a 1948.


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## mopac (Feb 24, 2011)

Tom is probably correct ( as usual) on your 312 being a 1948 production. The brass coupler weight was only
used in 1948 as far as I know. Yes there are Silver dry transfers. Give Doug a call at PortLines. The Train Tender
does not carry the dry transfers. I have a 312 and it has Silver numbers. Yours looks like it has been renumbered.
Something just does not look right with your cab numbers.


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## flyernut (Oct 31, 2010)

My silver lettered 312 also has a weird stamping on it.


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## hjstr6 (Jul 12, 2019)

I spent the entire day yesterday rebuilding this old 312. I cleaned and polished the reverse unit. Check all electrical connections and wires. The reverse unit cycles perfectly. I resurfaced the commutator I replaced brushes and springs with new ones. The local runs okay but is twice as fast in reverse then in forward. I rechecked all fingers and wire connections. On a track stand test the same thing happens, faster in reverse. I flip the train sideways so I watch the armature move. In forward the armature bounces back and forth. In reverse the armature holds steady. Upon disassembly I noted there was just one washer on the armature near the worm gear and made sure to replace it upon assembly. Any thoughts as to why I'm getting this differentiation in speed between forward and reverse. Is it normal for the armature to bounce back and forth while it is in forward?


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## hjstr6 (Jul 12, 2019)

I noticed that some armatures have this on the commutator side. When I dismantled this 312 the armature did not have this. I am not sure whether it should have one or not.l


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## skeeterbuck (Sep 29, 2015)

I try and add as many armature washers (usually 2) to get the commutator nearer to the brush tubes without actually contacting them.You need to install the brush bracket and tighten it down securely to test the clearance before installing the brushes. Then I add a washer to the rear of the armature shaft to minimize the shaft's play. When the armature is bouncing around that what causes the engine to run slower in forward that it does in reverse. When the engine is travelling forward the thrust on the armature shaft is trying to push the armature backwards towards the rear brush bearing. This is why you get the bouncing armature and slower speed going forward. The washer on the armature shaft next to the brush bracket bearing prevents this from occurring.Just be sure that went you assemble everything back together that there's no binding and the armature rotates freely. Also check that when the armature is pushed backwards that the commutator doesn't rub on the brush tubes. Good luck!

P.S. Sometimes you'll find where a previous repair was done that two brush springs are used (woven) together in each brush tube to apply more pressure on the brushes to prevent the armature bouncing. This is not good and a poor repair technique as it ultimately causes the brushes to wear down prematurely, extra friction on the rotation of the armature and grooving of the commutator's copper plates.


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## mopac (Feb 24, 2011)

I make sure there is at least 1 shim on each end of armature. Too many and motor may not run. I have had that happen. Not
binding just plates not lined up correctly with field.


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## flyernut (Oct 31, 2010)

Faster in reverse than forward is a common problem with flyers. Usually once you re-surface the armature the problem will/should go away. And I would add another shim to the armature shaft. They come in different thicknesses so keep playing with them.How do you re-surface the armature face??


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## skeeterbuck (Sep 29, 2015)

mopac said:


> I make sure there is at least 1 shim on each end of armature. Too many and motor may not run. I have had that happen. Not
> binding just plates not lined up correctly with field.


That's interesting. Do you remember how many washers was in there? I would think that by the time you added too many washers that the armature would bind up first.


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## AmFlyer (Mar 16, 2012)

Lets hold on a moment here! The arrow in the picture appears to me to be pointing at the oil slinger. These were added with the third version of the steamer armature beginning with 10/1949 production. Older engines will not have this and there is a different brush holder cap required for oil slinger equipped armatures.


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## skeeterbuck (Sep 29, 2015)

AmFlyer said:


> Lets hold on a moment here! The arrow in the picture appears to me to be pointing at the oil slinger. These were added with the third version of the steamer armature beginning with 10/1949 production. Older engines will not have this and there is a different brush holder cap required for oil slinger equipped armatures.


My thinking is that it most likely was changed out at some point and is not the original armature/brush bracket. After Gilbert made the change and once any old stock was used up, if you needed a replacement armature, this is what you would receive with the appropriate brush bracket.


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## hjstr6 (Jul 12, 2019)

flyernut said:


> Faster in reverse than forward is a common problem with flyers. Usually once you re-surface the armature the problem will/should go away. And I would add another shim to the armature shaft. They come in different thicknesses so keep playing with them.How do you re-surface the armature face??


On a drill press.


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## hjstr6 (Jul 12, 2019)

skeeterbuck said:


> That's interesting. Do you remember how many washers was in there? I would think that by the time you added too many washers that the armature would bind up first.


It was only one spacer on the front of the armature


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## skeeterbuck (Sep 29, 2015)

hjstr6 said:


> It was only one spacer on the front of the armature


I was responding to mopac's response in post #8.


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## hjstr6 (Jul 12, 2019)

AmFlyer said:


> Lets hold on a moment here! The arrow in the picture appears to me to be pointing at the oil slinger. These were added with the third version of the steamer armature beginning with 10/1949 production. Older engines will not have this and there is a different brush holder cap required for oil slinger equipped armatures.


That is not the armature I took out of my 312. The one I removed did not have an oil slinger.


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## AmFlyer (Mar 16, 2012)

That is what I thought hjstr6, a 1948 312 would not have the oil slinger. I just wanted to make sure you knew what it was and if that armature were put in the 312 you are rebuilding the brush bracket would also have to be swapped. The oil slinger armatures are 1/16" longer then the older style.


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## hjstr6 (Jul 12, 2019)

I have spent the entire afternoon experimenting with different size spacers. I have 0.020, 0.010, and 0.005 spacers. I have experimented using all different sizes with no luck. I was able to eliminate the armature wobble using a 0.020 on both front and back of the armature but I still have the same problem faster in reverse. I wish I had hair to pull out. Any suggestions.


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## flyernut (Oct 31, 2010)

Try a different armature and brush bracket assembly.


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## mopac (Feb 24, 2011)

Recheck your wires into the male plug. Those are stranded wires and if a few of the strands are broken, you just do not get the same amount of juice. Check your ohms readings from ends of harness to the male plugs.
I have a 336 that runs fine forwards but very slow in reverse. I am 95% sure I have a wire with poor connection.


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## hjstr6 (Jul 12, 2019)

Why does seem to be all firmly in place. However I didn't not replace any of the finger units. I probably could just resolder existing units. That would be the easiest thing to do right now.having difficulty getting parts from port line hobbies. They seem to be way behind.


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## flyernut (Oct 31, 2010)

Then don't use PortLines, use Jeff Kane at the Train Tender.


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## cramden (Oct 13, 2015)

hjstr6 said:


> I have spent the entire afternoon experimenting with different size spacers. I have 0.020, 0.010, and 0.005 spacers. I have experimented using all different sizes with no luck. I was able to eliminate the armature wobble using a 0.020 on both front and back of the armature but I still have the same problem faster in reverse. I wish I had hair to pull out. Any suggestions.


I don't know if you have read the repair clinic on Portlines site about this problem, but the last paragraph might be of interest. It's worth a try to see if this solves your problem. I haven't had to do this to any engines,(the routine fixes have always solved the faster in reverse issue,) but there is always a first time for everything.


faster in rvs


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