Model Railroading > Blue Box DCC Dilema

I have a number of Athearn blue boxed GP40s that I want to install sound decoders into.

When I built these models 25+ years ago, I chopped the ends of the frames off and body mounted the couplers.

Most installations I have seen utilize the old headlight brackets as part of the installation process, but my models no longer have this bracket, or even the frame mounting point for the bracket.

The dilema is, how do I get power from the frame? I have tried to solder wires directly to the truck, but then I have interference issues. I also do not think you can solder to the Athearn frame.

Anybody have any suggestions?


KM

Posted from iPhone

Hello KM

What if you drill and tap the frame, insert a screw, and solder to that?  

Larry

I've heard people do what Larry has suggested. Drill and tap a screw into the frame. 

Mike ONeill
Parker, CO

I have done this many times on my Blue Box old Athearns--use a 2-56 drill and thread cutter set--every hobby shop sells them.  Pick a spot on the frame where the screw head will not interfere with the shell when you put the shell back on.  I put the 2-56 drill in my power drill--go slowly and you can drill a hole through the soft metal on an Athearn frame in about 60 seconds.  Cut the threads carefully, using beeswax or oil on the thread cutter, going in and backing out repeatedly, so the metal you have just cut doesn't clog up the thread cutter.  To get a good electrical connection, use a small screw driver to scrap the black paint away from the area around your screw hole--scrape it down to bare better for good electrical contact.  I like to take those worthless old Athearn metal strips that are supposed to conduct electricity to the top of the motor, but over time work rather poorly, cut a small amount off of one of them to make a metal tab,  drill a hole through that, and use your screw to attach that small metal tab to the frame.  Then solder your electrical connection to the metal tab.  You will have a very reliable electrical connection that should be trouble free for years.

Best of luck.

UP9116

Larry020 Wrote:
-------------------------------------------------------
> Hello KM
>
> What if you drill and tap the frame, insert a
> screw, and solder to that?  
>
> Larry

That is the way to go.

SantaFeRuss

Posted from Android

When dcc first one.out you had to hard wire.,all the directs said for athearns to drill.and tap. Usually next the motor.some place. Often by the part of the motor where commutator is. Tape the frame there and solder right to the screw.use a brass screw. Only newer dcc instructions say use the light bracket only because it is easier and eliminates the tapping step.

Honestly I just solder wires directly to the metal plates on the trucks. It's easier and more reliable than trying to drill and tap a screw into the frame. The trick is to "tin" the plates with solder before you attach the wires.

Ted Curphey
Ontario, OR



Edited 1 time(s). Last edit at 02/16/17 08:13 by funnelfan.

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After you drill scrape the paint off around the hole to make a good contact. Speaking from experience, ensure your place the screw in a spot where it won't interfere with the shell. Have fun!
Matt

The threads of the screw inside the metal frame is the contact. There is no need to scrape any paint if you are going to solder a wire to the screw itself. If you are going to use the screw head to clamp a wire to the frame then yes, remove some paint.