Atlas MP15 (2016 release) Digitrax decoder install

[peteski]

There has been some grumbling about the fact that Atlas changed the design of this loco. Instead of using (what many modelers found unreliable) metal contact strips between the motor and decoder, the decided to use wires soldered to the circuit board.  In my opinion this was a good move and it will make this model more reliable in the long run.  The only difference in the decoder installation method is that 2 solder joints have to be made: something that majority of model railroaders can deal with.  Last night I went over my friend's house and performed the install.  Here is the procedure.

Decoder used: Digitrax DN163A4.

For most part we are following the steps outlined in the decoder instruction sheet.

Remove the shell and fuel tank and loosen the screws holding the chassis halves together.

Carefully unseat the lighting circuit board from the chassis and remove the metal contact clips from the 4 pads which provide positive electrical contact with the metal chassis. Make sure not to distort or lose them - they are vital for good electrical contact.

Carefully unsolder the black and red motor leads (wires).

Examine the top side of the decoder and locate the solder pads for the motor leads.  At this point I apply some flux and I tin those pads (to make locating them later easier, and to make the soldering the wires to them later easier.

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Install the metal clips onto the decoder's 4 power pickup pads.

Press the decoder board into one of the frame halves (I prefer to use the half which contains the motor and worms).   Make sure that the motor leads are routed out from the frame under the decoder as shown in the photos.

Make sure the plastic frame spacers are still in the frame and then reassemble the chassis, install the trucks and snap the fuel tank back in.  This is how the chassis will look at this point.

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There is plenty of wire length to comfortable solder the wires to the motor pads on the top of the decoder.  After soldering make sure the wires are routed through the natural notches in the side of the frame and then neatly tuck them between the frames in as shown in this photo.

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That's it - the installation is completer. The only extra step involved is soldering the 2 wires to the decoder.  No more intermittent motor contact to deal with.  Do a test-run to make sure everything works, reinstall the shell and add the model to your loco roster.

[rrjim1]

Red wire on the right and black wire on the right? 

[peteski]

The way the wires are attached in my instructions results in the loco running in the forward/reverse direction agreeing with the DCC throttle indication and in sync with the headlights on the decoder.     If someone's loco runs backwards (and opposite of the headlights) then simply reverse the motor wires soldered to the decoder.

[rrjim1]

You show that in the picture but that's not what this says!  Red wire on the right and black wire on the right? Could be worded better so its not confusing.

[peteski]

You show that in the picture but that's not what this says!  Red wire on the right and black wire on the right? Could be worded better so its not confusing.

Fixed - that's why it is nice to have a proofreader. Thanks!

[John]

is that a cold solder joint on the red wire 

[peteski]

is that a cold solder joint on the red wire 

Not at all - just the lighting. 
The photo is a bit out of focus too. It was not my workbench and not my photo setup. I was using friend's smart phone to take the photo.

[craigolio1]

Thanks Peteski. I will be soldering all motor leads in Atlas locos from now on. I have a True-Line Trains RS18 (Atlas RS11 mech). I installed a DZ### and trimmed the factory light board so I could use it for electrical pick up and motor contact there for making the hard wired decoder "removable".

This loco has a fully decked out lighting package. 10 LEDs. A while back I put it on the track to show a friend. Full light function both directions but no movement at all. I think I know exactly what's going on and now I need to open Pandora's box to fix the motor contact, which will be soldered this time. Ugh.

Great tutorial.

Craig

[NSGeorge]

Thank you for the tutorial.  I have extremely limited confidence in my soldering skills, especially on circuit boards.  You gave me the confidence to try, and I succeeded.

Thanks again!

[peteski]

Thank you for the tutorial.  I have extremely limited confidence in my soldering skills, especially on circuit boards.  You gave me the confidence to try, and I succeeded.

Thanks again!

I'm glad to see you tackle this task George, and that you were successful!

Maybe that inspired you to get more confident when soldering. After all, model railroading is a multi-faceted hobby and soldering is one of the important skills one can develop in our hobby. As with everything, practice makes you better  . Once you get more used to soldering and gain confidence you should be able to tackle more DCC projects where there are no plug-n-play options available.

For practicing general electronic soldering I recommend purchasing some soldering practice kits. If you Google  you will find lots of options.  I often deal with Electronic Goldmine (a surplus electronic vendor) and they have a range of this type of a kit available here . FOr gettign better handle on precision soldering and miniature components (like what we have on DCC decoders), they offer a kit just for that here

But don't limit yourself just to Electronic Goldmine. If you Google "SMD soldering practice kit" you'll find lots of options and a wide price range.