I want to install a decoder in my Athearn P59PHI. I’d like to do it tonight but I’m not sure how to solder to the motor brush contacts. I posted this in the dcc forum but there is 36 people viewing over in N scale and only one in DCC. Since I’m in a hurry could some one tell me if this is where I’m supposed to solder to. It just dosent look to easy to solder to without damaging it.
Not sure Johnny. Just remember when soldering to brush caps...make it quick...in and out in a hurry...JMO .
Most motor cups have a U shaped tab that goes under the cup to allow for contact to the pick ups. That would be the best place to solder to so you don't have to solder directly to the motor contacts.
There is two long brass tabs one on each side that slide down the side making contact with the motor brush contacts, the pickup tabs, and the light board. The instructions from the Digitrax site have you pulling them out, but I’m thinking of taping the ends and putting them back in so that I have something to solder to.
Not a good idea going to the caps while it is in the motor. Pop it out and catch the spring and the brush. The heat transfer will more than likely melt the casing. Mark
Oh I didn’t know they came out. I did pull the motor out looking for the place to solder to and it was real hard to put back, but I can take it out again. I don’t have a drawing of how it all goes back together, so we'll see.
I’m using the instructions found at the Digitrax DZ125 Athearn P59PHI decoder install page. , but I don’t exactly like how they are doing it. I think I’m going to make some changes especially for the lighting. I’m going to keep the light bar and move the decoder to the back so that the light bar can be put back and modify the PC board so that that there are two light circuits instead of one. I also want to think about soldering to those tabs that were taken out for the motor contacts.
I didn't bother soldering to the motor caps on my install. I stripped the ends of the wires and covered the ends with solder. I then put a kink in the soldered part of the wire so that it would fit snug in the hole in the brush cap. So far it has worked fine without any problems: I modified the original lightboard and use it for lighting:
I thought I would mention that instead of sodlering the red and black wires to the tabs you have marked, I sodlered them at the bottom of the loco so I didn't have to worry about damaging the plastic cradle: I ran the wires down either side of one of the driveshsfts to the bottom:
Alright I like that idea better! Thanks :thumbs_up: biggrin: And I see that you did the same thing as I did for the light bar, except I soldered underneath.
Johnny B, It looks like you were writing a post at the same time I added another about how I attached the red and black wires. I thought I would point that out in case you missed it.
Yes, I did just see that and I’ve decided that is what I'm going to do as well. Thanks I knew if I asked here in N-scale someone would have done this. Your idea of stuffing the motor wire in the hole like that reminded me of an electrical repair job I did years ago and I was searching for something like it. There was connection similar to what you have done, but we used some sort of conductive paste that was put in the hole and then the wire stuffed inside. The paste setup hard but was still removable from the hole buy pulling on it, only to replace it the wire end had to be cut off and striped back for each new connection. I don’t know what the stuff was only that it came in a tube. I think I’m going to ask around at work to see if anybody knows where I can get it.
That makes me nervous when regarding motor brushes. I'm unfamiliar with such a paste, but I can imagine the worst case scenario of the paste migrating to the armature, bridging the motor pole gaps and turning into magical blue smoke.
The paste setup hard but was still removable from the hole buy pulling on it, only to replace it the wire end had to be cut off and striped back for each new connection. I am interested if Johhny can find out what the stuff is. Set the motor on it's side...apply paste and wire...wait for it to harden...repeat other side. Innovation...I like it. :thumbs_up: .
Well you do have a point there. I can’t say that it will not do that because it is possible. I didn’t stick around to know how long it took to dry. I only know that it took some pressure to pop it out after it was dry and it was hard like dried caulking. I’m just looking at this hole and it’s not very deep. I think I need tape or something to keep the wire tight in the hole.
Indeed innovative, but another thing I would worry about is if it sets hard, and is applied too deep, it might affect the spring tension for the brushes. I'd also be curious how heat given off by the motor might affect the paste. If the heat softens the paste, that's the danger zone for eventual migration to the armature, especially on vertical brushes. But yes, if heat does not affect the hardening, and it is applied with care not to go too deep and affect the springs, this might be a great solution to certain decoder installs. I'd recommend further testing with a cheap, disposable motor before diving right in on that prized unit.
Oh wow, I was searching Google for a conductive adhesive paste and got malware attacked when I clicked on a site that looked like what I was looking for and had to shut everything down quick. There were flashing red widows popping up over my screen. I think I’m going to wait until I go to work.baffled:
I found out that stuff was a two part silver epoxy. My coworker said he remembers that it came with the part we were replacing. I didn’t remember it being two parts, but I guess it was in a package with two separate sides. When you cut it open, both sides mix together as you squeeze it out. He also remembered applying a thin coat of antioxidant inside the polished aluminum hole which might explain why we could pop out the original connection. My memory isn't so good either I didn't even remember that it was aluminum only that it was shiny like stainless steel. Oh wellsmile: Anyway I looked it up and I found a MG Silver Conductive Epoxy at $26 for 14grams at a computer place. I don’t know it will seep into the motor or not. My eyes aren’t that good and I can’t see inside that hole and I don’t know what its purpose is.
OK Done, and another one hit the Tracks I decided that I should post a conclusion to this installation. I was a little worried about the connection coming loose and causing spikes in the decoder so I decided to try something different. I decided to make a plug that would fit inside the hole and soldier to it. I experimented with different sizes of wires to find one that would fit tight. I first tried a #14 solid copper and it was too big then I tried a #18 which was too small. I did not have a #16 wire, but I think it would be perfect. So I tinned the #26 decoder wire and the #18 solid copper and first placed the #26 decoder wire in the hole and then I put in the #18. It is a tight fit and took a couple of tries because the solder adds to the wire diameter. Once I got it in place I used heavy pliers as a heat sink and quickly hit the #18 wire with the solder which immediately stuck to the #26. I then cut off the excess # 18 wire so that it was flush with the outside of the frame. It fairly tight and I was able to pull it out with a little pressure, but it’s not soldered to the cup. After I was all done I put it on the track it was running beautifully. Oh I did end up hooking up the track wires exactly like CSX Robert did only I cut a piece of plastic to fit inside the frame to hold the wire tight up against the frame. I’m not sure but I think Robert did something similar because he has something under the decoder just as I do. This is a photo of the Motor connection
