Servicing Ringfield Motors

[Chrisr40]

Hello

 

I have an old Hornby 3 Car DMU ( green ) that uses a ringfield motor - after running it for the first time in ages last night its very jerky and refuses to run unless you give it a big dollop of power, even then its very erratic.

 

I would like to give the motor a service as it was fine before and all I can think is it may have become a bit grotty inside ?

 

Other than the exploding springs which I know they contain has anyone got any tips or tricks for getting them apart successfully and making them run as well as possible ?

 

all contributions gratefully received

 

Thanks

 

Chris

[stewartingram]

Remove the motor bogie, and the pickup bogie too. From the pickup bogie, remove the axles (note which way round) and clean them. Also clean the slots that the axles run in - a good idea is to lightly run a round needle file in the slots until they are bright, not black. On the motor bogie, remove the wheels from the axles, a gentle twist with a flat screwdriver behind the non-geared wheel usually does the trick. This will allow the axles to pull out, clean them as before. Also poke a sliver of rag through the bearing holes using a cocktail stick, surprising what gunk that gets out. Remember that oil is necessary for lubrication between the axle and bearing surface, but that it is also an insulator and these surfaces are used for electrical connections, impossible situation really! Solution I have found is to use a spot of Electrolube for lubrication here and for the pickup bogie too. In effect, this is a 'conducting oil' (chemists will probably disagree, but that is near enough for us). Don't use WD40, that is a bodger's tool and will give longer term problems.

While the axles are out the whole motor can be stripped very easily. Be aware of the brushes and springs which tend to fly off though. If the brush contacts (metal plates on the face of the motor) are bent up, the springs and brushes can come out. Prise off the faceplate, to reveal the armature. Wipe the copper surface, even use a track rubber or fibre brush to shine it up. Clean the slots of carbon from the brushes. There should be no oil present here at all, nor Electrolube (or WD40!) Sometimes arcing occurs across the commutator slots, in extreme circumstances a small hole can be carefully drilled through the offending area to rescue an otherwise useless commutator.

Time to reassemble in reverse order. Usually I bend the brush contacts midway to give a bit of pressure to hold the springs in, also I put a dab of solder on the capacitor too (tv suppressor). A tiny drop of oil on the armature shaft behind the brass gear cures squeal; an even tinier drop at the other end (between the brush plates) is also required but don't get any on the brushes/commutator.

Total time to do the whole job about 10 mins (after you have done the 1st one for practise!).

[Chrisr40]

Many many thanks Stewart for taking the time to give me such a detailed reply - very much appreciated

 

Chris

[Calnefoxile]

Another little tip here, when dismantling the motor, try doing it inside a clear plastic bag, then if the springs do 'ping' they should be captured in side the plastic bag.

 

Here speaks the voice of experience after spending many a unhappy hour scrabbling around on the floor looking for flaming springs after dismantling Lima Mechs.

 

Regards

 

Neal.

[RedgateModels]

Only thing I'd add is that Hornby recommended a dab of "domestic vaseline" on the end of the armature shaft at the brush end. The reaoning is that this tends to stay in place and not run though and contaminate the armature.

 

click here for the Operation and Maintenance sheet for this type of motor bogie

 

 

[Chrisr40]

many thanks all - last response is really good too

 

thanks for the hints and tips

 

Chris