dnb Posted May 4, 2013 Share Posted May 4, 2013 Your advice & suggestions please. It's a Fleischmann BR360 shunter with a pancake motor, looks about new. I'd just lubricated the motor and gearwheel bearings and was testing by applying power to the brush caps. It was running nice and smoothly until one probe slipped!Therafter, the motor just doesn't turn. I've removed the motor, it turns freely by finger, with discernable "cogging". When power is applied, it turns just a fraction and stops. Current drain is high but not a dead short, though I can't immediately measure it. My meter shows about 12-15 ohms between each commutator segment.What have I broken?Helpful suggestions please.Thanks in advance,Nigel Link to comment Share on other sites More sharing options...
Wacol Posted May 4, 2013 Share Posted May 4, 2013 If you shorted the power has that damaged your power supply in some way. Have you tested another loco with it? Have you got oil onto the commutator, may have to open the motor up and clean the commutator and brushes. Keith Link to comment Share on other sites More sharing options...
dnb Posted May 5, 2013 Author Share Posted May 5, 2013 Thanks, Keith. The PSU's OK and the commutator's nice & clean with no build up of carbon between the segments. Nigel. Link to comment Share on other sites More sharing options...
Wacol Posted May 6, 2013 Share Posted May 6, 2013 Nigel, not much to go wrong with a motor, especially from just having a probe slip. Have you checked the brushes and springs, sufficient tension on the springs and length of brushes, caps firmly in place? Keith Link to comment Share on other sites More sharing options...
dnb Posted May 6, 2013 Author Share Posted May 6, 2013 Hello Keith, I'd say there was good, solid contact, as indicated by the heavy current drain. I've checked components with a meter. with the motor fully removed. As I'd expect with pure dc, the choke is as good as a short circuit, the suppression capacitor is open circuit. Brushes are like new, springs give a firm push. That all said, it's got to be something pretty basic - there isn't anythig complicated in sight! Thanks, Nigel Link to comment Share on other sites More sharing options...
Il Grifone Posted May 9, 2013 Share Posted May 9, 2013 It could be shorted turns on one of the poles. The resistance test would not show this (the resistance seems about right.) Close inspection will hopefully reveal bright copper and it may be possible to separate the wires and re-insulate with a spot of paint. A heavy current drain (anything above 300/400mA off load) indicates something badly amiss. It should be possible to prod the armature into rotation with a faulty pole. It will then run slowly and get hot. Link to comment Share on other sites More sharing options...
dnb Posted August 8, 2013 Author Share Posted August 8, 2013 Just to complete the tale, a new armature was bought for ~€40 - it worked first time ! I compared the new and old armatures - no measurable difference but the old one still doesn't work :-(Thanks for your contributions,Nigel Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.