Atlas classic TCS CN-GP DCC install

[ATSF_Ron]

Well, I'm supposed to be finishing up my GP60 install, but the soldering iron took a dump.  So until new parts arrive, I want to start on my GP30 fleet.  First up is a UP version from 2003, according to the Atlas web site.  Here are a couple pics from TCS documentation.  Problem is, I'm not sure how much to take off, even with the pics.  They zoomed WAY in.





Obviously the first pic is the unmodified frame.  The second is after Dremel grinding/Filing.  I'm really not sure exactly how much to take off.  The next two pics are of the first "tab" I'm supposed to remove, where the screwdriver is touching.  One is a side view and the other from above.
 





And the last two pics are the second tab that needs filing/grinding.  Again, from the side and top.






I have much clearer documentation on my GP60 with before/after pics from a non TCS website that clearly shows how much to remove.  Lacking that, I'm hesitant to start removing metal.  Obviously the Classic series Atlas locos are no longer made.  This one is a very sweet runner, so it goes without saying I don't want to ruin the frame.  Has anyone out there done this mod?  If so, can you point me in the direction of a thread or post pics of yours?

Thank you!

ATSF_Ron

[Sumner]

Might want to look at Brad's GP35's install (same I believe)...

https://n-scale-dcc.blogspot.com/search/label/Loco%3A%20Atlas%20Classic%20GP35

If you haven't bought the decoder yet and since you are going to have to modify the frame some have you considered another decoder vs. the TCN? 


https://1fatgmc.com/RailRoad/Decoder-1/page-28.html

The ESU above is a better decoder and at around $30-$31 might be as cheap as the TCN or cheaper?  More functions and better motor control and very small.  The Zimo there is even smaller and not too much more.  Either one would reduce frame milling.  I really like the LokPilot myself.

Sumner

[ATSF_Ron]

Thanks Sumner, those are good options to consider.  I only have 2 of the TCS, and one is in my GP60.  I may go with one of your suggestions, or I may bite the bullet and try the one I have with some slight milling/grinding.  Someone sent me a PM with some good suggestions.  I think I paid $30 each for my TCS decoders, so the other ones are comparable in cost.

[peteski]

After having some issues (and considering their prices vs. features and bugs), I'm not a fan of TCS decoders since much better ones are readily available (for wired-in installs).

[ATSF_Ron]

Thanks to @Bendtracker1 I'm moving forward with my GP30 DCC install.  Since I bought two of the CN-GP decoders, I'm using my 2nd one on the UP Atlas classic GP30.  The GP60 went well, but I need to tweak the low end running. Anyhow, as I disassembled things, I saw some powdery black gunk on the inside of each frame half directly opposite the motor location.  I'm not sure what this is or if I should be concerned with it.  Zoom in on the pic below...



So I took Bendtracker1's advice and gently pushed in each half of the decoder into the frame after the motor and drive shafts were removed.  There are some obvious places where the frame needs to be filed down/ground with a Dremel to create clearance for each part of the decoder.  The pics below show these locations marked in black sharpie.  The screwdriver points to a spot I think may also need a slight filing/grinding.  My best guess is no more than 2mm in the black sharpie locations.  I'll be going slow 'n low.  Just like smokin' meat!










I thought I'd post these pics in case anyone else needs to grind a frame and is using this decoder.  I wasn't able to locate any clear (to me anyway) before/after pics.  I will post more progress after Christmas, as family is coming tomorrow.  Wishing all of you Railwire folks a Merry Christmas and safe travels if you are out and about during the holidays.

ATSF_Ron

[nickelplate759]

That black powdery gunk is very likely carbon (mostly) from sparking motor brushes. Normal wear and tear unless this is a newish model.

[peteski]

That black powdery gunk is very likely carbon (mostly) from sparking motor brushes. Normal wear and tear unless this is a newish model.

That's exactly what that is.  This is the same dust that can accuumulate in the commutator's gaps (if commutator is contaminated with oil) and greatly increase the current consumption of the motor and  make it run poorly.

But like George mentioned, it is normal to see the powdered brush material in well-used motors.

[ATSF_Ron]

Thanks guys.  It's a 2003 release with apparently little run time on it.  It's only been run an hour at most since I bought it earlier this year.  Great runner, quiet with excellent slow speed DC control.  DCC should make it even better!

[ATSF_Ron]

This first pic shows a small notch in the frame which needs to be filed/ground to prevent motor wires from being pinched.  Not shown is a groove I cut in the plastic motor saddle for the same reason.  That step is clearly shown in TCS instructions.


And doing some test running before final trimming of wires and replacing the shell.  Another successful and relatively easy DCC install.

I'm quite happy with this decoder so far.  With my GP60 I found that 28 speed steps had accidentally been selected instead of 128.  When in 128 speed step mode, the slow speed operation is amazing.  These two locos will crawl along at 1 smph or less.  I have a few of the older Kato drive Atlas SD7/9 locos to convert, so I'll stick with these decoders for the time being as the install procedure is very similar, and minimal frame mods are needed.  Since I only need direction and forward/reverse lighting, these decoders are a good fit for me.