ATHEARN MOTOR TO DECODER CONNECTIONS

[WestIslandRon]

I have a number of Athearn F-7 engines that I'm converting to DCC.  I know to insulate the bottom brass motor clip from the frame.  I plan on soldering the gray / orange wires to the brass motor clips.  My question is this - which wire (gray or orange) goes to the bottom clip and which one goes to the top clip so that the motor / headlights match the direction of movement?  I know I can take a 50/50 chance and solder one up, but I'd like to complete the project for all the engines before I head down to the club's DCC layout and programming track.  I know there's a CV value that will reverse the motor connection polarity through the decoder, but does that affect the headlight direction of travel orientation?

Thanks

[rrinker]

 Under DC, the loco is supposed to move forward when the right rail (engineer's side) is positive. I pretty much all Athearn BB locos, the clips coming up fromt he trucks are on the right side - those go to the top of the moter with the long clip that connects the motor to the two truck towers. The frame, which is where the bottom motor clip touches, the one you need to clip the tabs off and put a layer of tape under, goes to the left rail.

 So the top of the motor should get the orange wire, the grey goes to the bottom.

 I just saw another set of install pictures where they put a small piece of styrene in the bottom where the contact was. Interesting. Kapton tape is usually good (it's very resistant to being rubbed through, and not gooey like black electrical tape).

http://www.girr.org/girr/lamrs/lamrs_blue_box.html

                                --Randy

 

[mbinsewi]

Randy, that link is a nice and simple tutorial on a BB conversion.   I've seen many others.

The DH163AT is long gone.

Mike.

[rrinker]

 Yeah but a decoder's a decoder. I trry to explain that when posting links to the TCS install pictures - the install will be exactly the same no matter what brand of decoder you use. 

                           --Randy

  

[Overmod]

rrinker

the install will be exactly the same no matter what brand of decoder you use. 

With the very, very important caveat that it be a NMRA-standard-compliant decoder.  

We have discussed a number of 'things' that have decidedly nonstandard, and occasionally counterintuitive, connections.

[RR_Mel]

I don’t cut off the contacts on the bottom of the brass strip, I use my long nose pliers close to the joint to compress the contacts back into the brass strip.  Someone might want to redeploy the original Athearn configuration in the future.

I used the thin Styrene for years until I bought some Kapton tape.
 

Mel



 
My Model Railroad   
http://melvineperry.blogspot.com/
 
Bakersfield, California
 
I'm beginning to realize that aging is not for wimps.

[rrinker]

 If you look at the link I posted, that's what they did as well - bent the contacts back. But the don;t always stay, so he had to solder them to keep them flat.

The simple trick to not changing any of the original parts is to swap the contacts - the top one doesn't have the tabs. But you have to be careful because the tabs are also the brush covers, don't let the brushes and springs fall out, and they also hold the motor together. Having one spare of either type helps - that way you only have to remove one at a time. 

                        --Randy

 

[WestIslandRon]

Randy,

Thanks for the quick reply.  This is exactly what I needed.

I don't bother to bend the brass 'fingers' back, but the idea of swapping the clips top to bottom sounds even better.   I also am a belt and suspenders guy.  I lightly GOO'd a thin piece of styrene to the slot in the frame and then covered it with electrical tape.