brianH Posted July 26, 2012 Share Posted July 26, 2012 Has anybody successfully converted the older type of ringfield that has a brass plate held on by three screws and the brushes retained by small brass clip on caps, not with a plastic brushholder plate and "silver" strips to hold the brushes in place. The left hand brushholder is insulated, but the right hand one is grounded to the plate. The three mounting screws can be replaced with plastic and the plate insulated from the motor body, but the armature shaft still provides a connection. Thanks Brian Link to comment Share on other sites More sharing options...
Fishmanoz Posted July 26, 2012 Share Posted July 26, 2012 Hi Brian, SonofTriangMan is one who I think knows this one. I even think you might find a very full description on how to do it from him (I think) a couple of months back in this thread if you do a search. Link to comment Share on other sites More sharing options...
Blackbird Posted July 30, 2012 Share Posted July 30, 2012 brianH said: Has anybody successfully converted the older type of ringfield that has a brass plate held on by three screws and the brushes retained by small brass clip on caps, not with a plastic brushholder plate and "silver" strips to hold the brushes in place. The left hand brushholder is insulated, but the right hand one is grounded to the plate. The three mounting screws can be replaced with plastic and the plate insulated from the motor body, but the armature shaft still provides a connection. Thanks Brian Hi Brian, Your basic concept on insulation is correct, but the armature shaft has no electrical connection to the armature wiring. Link to comment Share on other sites More sharing options...
The son of Triangman Posted August 2, 2012 Share Posted August 2, 2012 The early ringfield is pretty easy to convert. The armature shaft is insulated by the plastic bearing holder in the faceplate and by a washer underneath the face plate. The washer may be worn on your loco giving a connection, I still keep spares for this early motor in stock if that's of any help? Insulating the faceplate from the chassis block is easy with nylon bolts and washers. Link to comment Share on other sites More sharing options...
The son of Triangman Posted August 2, 2012 Share Posted August 2, 2012 Made quite a few early ringfields DCC and they run lovely if in good fettle before conversion. Link to comment Share on other sites More sharing options...
brianH Posted August 4, 2012 Author Share Posted August 4, 2012 The shaft runs in a brass bearing in the faceplate, hence the problems I was having. What I ended up doing was modifying the faceplate so that both brush holders were insulated from it. Just testing it under DC before going further and converting it. Link to comment Share on other sites More sharing options...
Bampy Posted August 4, 2012 Share Posted August 4, 2012 I have not a clue but Im trying to digitise an old hornby western courier and Im Struggling Link to comment Share on other sites More sharing options...
poliss Posted August 4, 2012 Share Posted August 4, 2012 Have you looked at the conversions on Brian Lambert's page? http://www.brian-lambert.co.uk/DCC.htm#Decoder Installation. Link to comment Share on other sites More sharing options...
Fishmanoz Posted August 5, 2012 Share Posted August 5, 2012 Bampy, the Brian Lambert site is certainly a good one. In principle, a DCC conversion is simple - you connect the decoder's red and black wires to the loco pickups and the decoder's orange and grey wires to the motor. The only problem is that if you get a short between either of the red and black wires and either of the orange and grey, the decoder self-destructs. Unfortunately, some of the older locos are made with a common connection between one pickup, the chassis and the motor (it makes the wiring simpler) and if you install a decoder with this arrangement, it destructs. You must first break that pickup/chassis/motor connection. A case in point is some of the old ringfield arrangements and the posts above tell you how to break the connection by using nylon screws etc. Link to comment Share on other sites More sharing options...
Blackbird Posted August 7, 2012 Share Posted August 7, 2012 The armature shaft has no electrical connection to the winding once the brush connection is isolated. The only reason that the armature shaft is electrically connected, (although not part of the conductive path) is that it is electricaly (mechanically) in contact with the chassis. The chassis has to be isolated for DCC operation. The armature windings and slipring are electrically isolated from the shaft. Link to comment Share on other sites More sharing options...
Fishmanoz Posted August 7, 2012 Share Posted August 7, 2012 See poliss's post and links on Class 47 conversion next to this thread in DCC for a full explanation. Link to comment Share on other sites More sharing options...
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