Simon G Posted December 30, 2011 Share Posted December 30, 2011 A friend of mine has given me a Hornby Castle to look at as it is running slowly. It is a Chinese made version with the 3 pole Ringfield type motor in the loco made in approx 2003 as part of a Western Pullman set. I have lightly lubricated all the right points and removed the motor from the chassis. The chassis runs freely. The unconnected motor is still reluctant to run at a decent rate and has poor slow speed control. I have also noticed a smell similar to X04 motors when they get hot. I havent yet dismantled the motor itself. My thoughts on this are that either the armature is faulty in some way (but each pole has a reasonable electrical resistance across it) or that the magnet has lost some of its power. There is some evidence that the loco has had an impact at some time as one of the buffer beams has been bashed and the plastic lug on one of the body fixing screws has broken off. Has anyone any other suggestions which might help diagnose the problem? Simon Link to post Share on other sites More sharing options...
hollywoodfoundry Posted January 3, 2012 Share Posted January 3, 2012 Simon, Unless someone has experienced this problem before, it might be a bit hard to diagnose. If possible, can you run the motor on its own and measure the current consumption? That will tell us quite a bit. Link to post Share on other sites More sharing options...
Simon G Posted January 4, 2012 Author Share Posted January 4, 2012 Hi Geoff, I have run the motor with the wheels suspended off the ground so that it is effectively just the motor turning the driving wheels with no load. With currents of about 0.35 amps and 0.5 amps, the motor doesnt turn. In order to get it to turn the current had to rise to about 0.8 amps. There was then a wisp of smoke from the motor, so I shut it off quickly! Would it help to separate the motor from the rest of the chassis and run it completely without load? Thanks, Simon Link to post Share on other sites More sharing options...
hollywoodfoundry Posted January 4, 2012 Share Posted January 4, 2012 Hi Simon, Yes, it would certainly be best to separate the motor, as there may be aproblem in the drive train that is loading down the motor significantly. It is always best to split the motor away when doing work on the chassis. My guess would be that there is some binding in the drive train from what you have said. Link to post Share on other sites More sharing options...
Simon G Posted January 5, 2012 Author Share Posted January 5, 2012 Hi Geoff, Have separated the motor from drive wheels, so it is just turning a couple of drive cogs. With a current of 0.3 to 0.35 amps, the motor doesnt turn. It needs to be increased to between 0.5 and 0.6 amps before it turns, then the current drops to about 0.35 once it is turning. At this current, there is soon a small of burning/overheating, so I have only run it for a few seconds each time. The chassis seems to run freely and without any obvious resistance, with the motor disconnected. Cheers, Simon Link to post Share on other sites More sharing options...
hollywoodfoundry Posted January 5, 2012 Share Posted January 5, 2012 Hi Simon, That does not sound good for the motor. At this point you have two options, first try to resurract the motor, or two go directly to trying to obtain a new motor. A new motor might be the best option, particularly as the odd bit of smoke may have already damaged the motor. I am sure someone here will know where to get a replacement motor, and will advise shortly. If you want to try and repair the motor, the first thing woyuld be to try rotating the motor by hand to see if the bearings may be dry or siezed. In any event, I would put a tiny drop of oil on the bearing and see if it frees up. Then repeat the current test. Link to post Share on other sites More sharing options...
Simon G Posted January 16, 2012 Author Share Posted January 16, 2012 Hi Geoff, It seems to be sorted now. I finally plucked up the courage to dismantle the motor. The cause of the poor running and smoke was clear when I saw the armature. The face was very black and oily. I did a resistance check across the 3 poles which was about 4 to 5 ohms each, ie the black carbon deposits were conducting and almost shorting out the motor. A gentle wipe down and a clean with a cotton bud and meths cleared away the oil and most of the black colour. A further resistance check showed approx 17 to 20 ohms across each pole, which must be about right. The armature coils look immaculate, with the exception of some odd hard gray/blue deposits. I have left these alone and reassembled the motor and off she ran. Quite smooth and very happy pulling 7 coaches around the club layout track. Not the fastest loco in the world, but at least it was running well and wasnt smoking. I took a picture of the armature and deposits - hasnt come out particularly well, but you can see them. Thanks for the help, Simon Link to post Share on other sites More sharing options...
hollywoodfoundry Posted January 17, 2012 Share Posted January 17, 2012 Well Simon, good on you for having the courage to gut the motor, and it had a positive outcome. I have no idea what the black residue might have been, but obviously with it cleared off the motor was OK. I am wondering if the odd grey/blue material might have been some putty or something similar placed in there to balance the armature? Link to post Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.