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Discussion Starter #1 (Edited)
All,

A member on another forum asked for help to wire a 21165. I discovered the documentation for this engine is lacking..so..I decided to produce two photos and a sketch showing how it’s wired. I tried to keep it simple with no verbiage, letting the pictures explain everything.

Rich





 

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Neat ... nice job with the labeling.

So it looks like your "hot" lead wire goes into the armature (via in/out brushes), and from there, to the E-Unit which routes the direction (clockwise or counterclockwise) of current flow through the field coil ... inducing forward or reverse direction.

Thanks,

TJ
 

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Very nice job, Rich! Thanks for your contribution! TJ, if you look closely at this one, you'll see two horizontal metal tabs on the left side. One's at the top, right of the word "left"; the other at left bottom, along the line leading from "Top Reverse Unit Connection". This is what makes the pre-bankruptcy steamers from American Flyer a pain to work on: tab and slot assembly. Those metal tabs have to be worked out of slots in the plastic shells to get access to the innards, and it's difficult without damaging the shell each time. The prewar and postwar production years were made to be owner-maintained and run forever: this final gasp of production cut quality to cut costs. They run well, but they lack a reversing unit and reflect the company's struggle at the end.
 

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Discussion Starter #4 (Edited)
TJ: That’s a good way of putting it. In my case it’s a.c. so even though the current flow isn’t in one direction or the other, it’s a very good way of visualizing how the reverse unit switches the connections, and useful when you’re troubleshooting it.

Len: You’re right about working on these steamers. I have a nice spreading tool I bought. It makes it a little easier to get the motor out without damaging the plastic shell. I got the tool to spread the aluminum passenger cars but it’s been handy for trucks, and for the “Casey Jones” type engines. I like their motors and usually can buy an engine for parts, for almost nothing. This 21165 happens to run so well that I decided not to cannibalize it and plan to put a coupler on the front and make it into a switcher. Glad to hear you enjoyed vacation!
 

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Rich ... yeah, I realize AC ... same as my Lionel stuff. Sine-wave current, so no real "direction". But I like to visualize the "direction" of the circuit, anyway, when mapping out a wiring diagram ... especially one with an e-unit. That said ...

I'm no ee-guy, and even though the AC current is oscillating in a sine-wave manner, I do think that the near-instantaneous directional flow of current (i.e., up the sine wave crest, or down the trough) acts the same was as DC when one considers what magnetic field is generated within the field coil, and how this creates a magnetic "push" to the electromagnet in the armature. So, in this sense, if you consider how the field and armature work together, and consider what's happening in a very short time interval (say 1/4 of a second ... a tiny fraction of 60Hz singe sine wave), then even an AC motor like this has "direction" in it's current flow. Accordingly, an e-unit can be used to reroute each small-duration pulse of power to either forward or reverse loco direction. My understanding of it all, anyway!

Reck ... thanks for the explanation. I had no idea that this generation of AF loco were built such that one could NOT so easily "get under the hood". Makes me feel a bit less peeved about my old Lionels where I can't remove the armature from the motor cheeks.

Great info, guys ... thanks for sharing!

TJ
 

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Discussion Starter #6
TJ,

It's been so long that I've forgot a lot of a.c. theory. If fact I was in school a little after Franklin did the thing with his kite and key so the technology has advanced a little since then.

Rich
 

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Thank you, Rich---we had a great time. I found the perfect spreading tool for those aluminum cars---or thought I did, anyway---when I was refurbishing some. I was trying to get the frame out of the shell and was having trouble: looked down at the table and there were a couple of rechargeable AA batteries that looked promising. They were the perfect size, spread the aluminum shell just enough to where I was only working against the accumulated corrosion in the slot...intil I realized the batteries were heating up and swelling! What a dummy!

I ended up getting a 1/4" hex-head bolt, using the head against one inner edge and wound the nut down to just the right length that, when I twisted the bolt, it gently spread the shell open.
 

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Rich, thank you! That looks like it would do it and you're right, the price is decent. Now, if I can ever catch Doug Peck with his shop open!
 
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