I am moving into DCC for my next N Scale model RR. Looking at my old loco stock I have number of split frame locos to which I want add decoders. I read in lots of places on the web that the frame needs modification but none are very specific. The question I have is what is the frame modification for?
Usually, modifying the frame is to create space for the decoder. However, in a few model-specific instructions, I have seen steps that create room for wires (especially to the motor).
Two vendors for DCC-ready frames for N-scale locomotives are Aztec (http://www.aztectrains.com/pages/OnlineCatalog.html) and Southern Digital (http://www.sodigi.com/prod02.htm). I have not used either, but I will probably wind up with a few Southern Digital Digiframes. Theirs are made of a different alloy than the original frame, which makes them equal to or heavier than the original despite the fact that there is an opening for a decoder. Aztec’s, as I understand it, are modified original frames, so some weight is lost.
If the N scale split-frame non-DCC ready locomotives are anything like the HO scale ones, such as Bachmann’s, you must separate the frame halves in order to get to the motor and connect the decoder’s wires to it. There are bronze wipers attached to the motor brushes that press on each frame half for electrical pickup. The decoder’s wires connect to these wipers, and then the wipers MUST be totally insulated so they no longer touch the frame, or the decoder will be destroyed.
I still run DC in HO. My daughter has N, and her Bachmann split frame developed electrical pick up problems. I finally modified the pick up system by soldering wires from the loco’s wipers directly to the motor and lights, bypassing the frame. The little loco (F7) now pulls with out the stops and stalls.
I’ve used Aztec’s frames and they are very good. I have three SD frames sitting on my bench waiting to be installed, and they also look very good.
Sir I have come up against this issue myself i have 7 Bachmann dash 8’s that are of the older split frame with no provision for direct plug in of decoders, i could see a few points for you to consider.
1, the 2 halves of the frame are isolated from each other this is good.
2, you will have to remove part of the frame to have space for the decoder
3, i would completely rewire the loco to the decoder avoiding any kind of brass strip contacts.
4, the gap between the frames would come in handy to conseal the wiring.
Any way as we say down under thats my 2 bobs worth