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Soldering the black/ground wire to the frame on Athearn Blue Box DCC upgrade

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  • Member since
    December 2005
  • From: Franklin, OH
  • 153 posts
Soldering the black/ground wire to the frame on Athearn Blue Box DCC upgrade
Posted by rrlcommish on Sunday, March 25, 2018 4:12 PM

Hi all,

I am upgrading my old Blue Box Athearn loco to DCC and sound using a Sountraxx Tsunami2 PNP.  So I have watched many YouTube videos on this and every time the videoer either solders the black wire directly to the frame or to the old light mounting bracket.  Unfortunately my old light bracket broke off many year ago, so I was just trying to solder to the frame.  For the life of me I cannot get solder to stick to the frame.  I even tried grinding the frame down to bare metal using a Dremel but still no luck.  Obviously I am not a metallurgy expert, so what am I doing wrong and/or how can I get that ground wire attached to the frame (i.e. left rail pickup)?  Thanks!

  • Member since
    February 2002
  • From: Reading, PA
  • 30,002 posts
Posted by rrinker on Sunday, March 25, 2018 4:45 PM

 You don't. Drill and tap a hole and install a brass screw. Solder to that - it will actually take solder.

                                --Randy

 


Modeling the Reading Railroad in the 1950's

 

Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.

  • Member since
    December 2015
  • From: Shenandoah Valley
  • 9,094 posts
Posted by BigDaddy on Sunday, March 25, 2018 5:20 PM

Different loco, same problem.  I had no brass screws of that size. 

I had blackened screws and scavenged a piece of brass from a 9mm shell casing with a razor saw.  Drilled a hole in it and soldered to it and used the screw I had.  Not all shell casings are brass, but you can tell just by looking.

 

Henry

COB Potomac & Northern

Shenandoah Valley

  • Member since
    April 2004
  • From: Ontario Canada
  • 3,574 posts
Posted by Mark R. on Sunday, March 25, 2018 7:18 PM

I solder both my truck wires directly to both metal plates of the trucks themselves. I don't like relying on mechanical contact points to conduct electricity like the truck to frame contact in the old blue box Athearn.

Mark.

¡ uʍop ǝpısdn sı ǝɹnʇɐuƃıs ʎɯ 'dlǝɥ

  • Member since
    December 2005
  • From: Franklin, OH
  • 153 posts
Posted by rrlcommish on Sunday, March 25, 2018 7:25 PM

Well, Randy you were half right.  I drilled and tapped a 2-56 brass screw.  However, for whatever reason, the screw would not take solder either.  Same problem, it just slid right off.  I have been soldering for years, I cannot imagine what I am doing wrong.  Yes, I am using flux too.  Anyway, what I did was tap the hole further all the way through the frame and just screwed the wires right to the frame old fashioned style.  Works perfectly.  I appreciate the tip though, it worked out just fine!  I appreciate everyone else's comments as well.

  • Member since
    March 2011
  • 1,950 posts
Posted by NVSRR on Sunday, March 25, 2018 7:57 PM

I just solder right to the bracket mounted to the frame for the old light. Never had a problem.  No drill and tap needed.   

Wolfie

A pessimist sees a dark tunnel

An optimist sees the light at the end of the tunnel

A realist sees a frieght train

An engineer sees three idiots standing on the tracks stairing blankly in space

  • Member since
    April 2007
  • From: Stevens Point, Wisconsin
  • 112 posts
Posted by arbe1948 on Sunday, March 25, 2018 8:04 PM

While tapping a brass screw into the frame and soldering to that works, i just solder black wires to one side of the trucks and red to the other, and then to the black and red wires of the decoder.  The motor I isolate with Kapton tape.

Bob Bochenek
  • Member since
    December 2005
  • From: Franklin, OH
  • 153 posts
Posted by rrlcommish on Sunday, March 25, 2018 8:08 PM

arbe1948
While tapping a brass screw into the frame and soldering to that works, i just solder black wires to one side of the trucks and red to the other, and then to the black and red wires of the decoder.  The motor I isolate with Kapton tape.

Bob,

Where on the truck do you solder to?  Aren't you worried the constant pivoting of the truck would eventually work your joint loose?  Or fatigue the wire to the point it breaks?

  • Member since
    April 2007
  • From: Stevens Point, Wisconsin
  • 112 posts
Posted by arbe1948 on Sunday, March 25, 2018 8:29 PM

Just to the side between the wheels, making sure to keep clear the sideframe mounting hole.  Since that is near the center of the truck there doesn't seem to be a terrible amout of flexing.  Anyway, I haven't had any break from the ones I have done.

 
arbe1948
While tapping a brass screw into the frame and soldering to that works, i just solder black wires to one side of the trucks and red to the other, and then to the black and red wires of the decoder.  The motor I isolate with Kapton tape.

 

Bob,

Where on the truck do you solder to?  Aren't you worried the constant pivoting of the truck would eventually work your joint loose?  Or fatigue the wire to the point it breaks?

 

[/quote]

Bob Bochenek
  • Member since
    May 2010
  • From: SE. WI.
  • 8,253 posts
Posted by mbinsewi on Sunday, March 25, 2018 8:55 PM

I do a combo of what Randy and Henry do, and those that tap a 2-56 hole in the frame, I make a little "L" shaped bracket from brass stock, drill a hole in it for a 2-56 screw, solder the black wire to the other half, and use a typical non-brass 2-56 screw, and screw the bracket to the frame, after I have cleaned the brass bracket, and the paint coating off the frame.

I always wanted to try what Bob and Stix do, solder to the metal side plate of the gear box.  I'll give that a try next.

The light bracket on the front does work, along as the bracket is still tight, and doesn't move, but I usually take that off.

Digitrax used to make a decoder harness just for Athearn BB locos, but have long since discontinued it.  The first decoder install I did, uses one of these early harnesses.

Mike.

  • Member since
    February 2002
  • From: Reading, PA
  • 30,002 posts
Posted by rrinker on Monday, March 26, 2018 6:34 AM

 Except those harnesses clipped to the shakey headlight bracket for the frame side.

What's funny is the only time I've EVER had a problem with the contact point being through the bolster is with a relatively new RTR RS3. Soldering wires to the trucks didn't even fix that one. Every other similar design loco - original BB ones, and the early P2K locos before they went with wires directly to the trucks, have never had any contact issues.

As for soldering to the brass screw - are you only using something like a 15 watt iron? If the solder isn;t sticking then there's not enough heat getting to the metal. The chassis is going to act like a giant heat sink so you need decent power, about 40 watts, AND a VERY clean and shiny tip so the heat transfers quickly. That will allow the heat to transfer faster than it all bleeds away. A dull, worn tip will transfer heat so slowly, you'll end up just warming the entire chassis, not hot enough to melt solder.

                                    --Randy

 


Modeling the Reading Railroad in the 1950's

 

Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.

  • Member since
    May 2002
  • From: Massachusetts
  • 2,899 posts
Posted by Paul3 on Monday, March 26, 2018 10:17 AM

One might also try putting solder on the brass screw (tinning it) when it is not screwed into the chassis.  I'd use a "3rd Hand" type holder for the screw and make sure not to fill in the slot or Phillips head socket with solder.  The solder should go right on.  After you screw it into the chassis, you should be able to take a tinned wire and solder it to the tinned screw with far less trouble.

Personally, I prefer the brass washer w/tab method and a mechanical connection by tightening the screw down.  But what I've done in a pinch, when I don't have a brass washer w/tab, is to strip a longer piece of insulation off the wire than normal.  Then I form it into a loop around the screw and wrap it around itself.  I remove the screw, and now I have a loop of wire.  Next I tin the wire to itself and tin the loop.  After the solder sets, I re-insert the screw and screw it into the chassis.  Tightening the screw will mash the softer solder down, forming a good connection while the solder will keep the wire from fraying apart.

  • Member since
    November 2006
  • From: NW Pa Snow-belt.
  • 2,216 posts
Posted by ricktrains4824 on Wednesday, March 28, 2018 10:00 PM

Drill and tap the frame. 

Make sure the tap is good.

Solder the wire to a brass washer, then screw the washer, with a brass (or metal) screw, to the frame.

Frame connection now complete.

Ricky W.

HO scale Proto-freelancer.

My Railroad rules:

1: It's my railroad, my rules.

2: It's for having fun and enjoyment.

3: Any objections, consult above rules.

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