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3 Responses to Middle Rail Rollers
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Are the rollers grooved all the way around the circumference? if so that is normal wear so would not be making good contact. Or are the roller(s) grooved in only one place? If so then the roller is not rotation and is stuck. These problems are quite normal in older Lionel locos.
Your problem could be caused by a variety of faults, for instance when did you last clean and oil the motor bearings. it could be a carbon buildup shorting in the commutator grooves, use a wooden cocktail stick to clean out the grooves or it could be the the brush’s worn right down and not making contact with commutator properly giving intermittent power to the armature. check all soldered joints (you did not say what manufacture the loco’s were made by so I am guessing Lionel for starters) having checked that the motor runs OK when power is supplied to the wires leading to the brushes if the motor runs continuously when power is supplied you need to look at the track and it’s connections if you have a test meter check each length of track to make sure that there is a continuous current supply, a rusty rail joiners, loose pin, broken wire or damaged soldered connection could be the problem.
Now check the height of the centre third rail and see if it has worn down, to do this turn off all electricity to the rails or you could end up with a short circuit, if you have a steel rule place it across the two running rails and see if there is a gap between the rule and centre third rail, if there is you will probably need to adjust the bar holding the rollers by slightly bending it down, hold the end of the bar nearest to the pivot pin and apply pressure at the roller end, this way you will not damage the pivot pin.
If the groove in the roller is very deep you may need to get a replacement set of rollers or you could make them yourself out of brass rod, obtain a piece as large a diameter as the rollers then find the centre of the rod and drill a hole the same size as the roller pin, if the roller is larger in diameter in the middle then the brass bar needs to be shaped in a lathe or in the chuck of a drill using a fine file being finished with fin emery paper, sometimes you can find spares on eBay but they can be quite expensive, I look for models that are being sold as spares or repairs making sure that all the parts are there that I want. Have you checked the controller, some controllers have a continuous winding round an insulated strip of mica or paxolene and contact is made when the arm fixed to the controller comes into contact with it and over time both items can become loose or worn down by continuous friction. I hope that you will find this list of tips helpful but it is by no means complete and perhaps someone else could take over where I have left off.
Kindest regards john.
I forgot to mention another method of rectifying the grooves in the rollers and it can also be used on Hornby third rail pick up spades and a variety of other worn parts that rub on another material without lubrication.
For this you will need some low melting point silver solder (not ordinary solder which is soft) some flux (I use Borax if I can’t get easy flow) a gas torch and two very dry house bricks to use as a hearth (If you use them wet they will explode with the heat) detach all the rollers and wash them in petrol lighter fuel to get every vestige of grease and dirt of them a toothbrush is very good at getting into the nooks and crannies and finish of with a fine wire brush (In all types of soldering cleanliness is next Godliness) .
The procedure is this, mount one house brick into the jaws of a metal vice if you have got one and about one inch from the long edge chisel out a shallow groove that matches the diameter of the roller (If you have not got a large enough vice then you will need a heat resistant soldering mat which you can buy from B&Q to put between the brick and work bench, and I stress that this procedure should only be undertaken in a very well ventilated environment as the fumes are toxic if inhaled) next cut or break the 2nd brick in half and place on the 1st brick in a V shape to act as a baffle to direct the heat to the far side of the roller approximately one inch away from roller so that when you apply the flame all the heat is directed at the work piece, mix some flux with a drop of water to make a thick past and spread it into the groove that needs filling with silver solder and I would stress that what you use to apply the flux with is perfectly clean and grease free, next place the roller in the groove in the brick and heat work piece until the flux looks as if it has turned to glass, dip end of silver solder into flux, heat and melt solder into groove, allow to cool naturally to avoid distortion, you can pick the roller up with clean pliers as soon as the solder has hardened and put behind the brick baffle so that you can work on the next one and so on.
The silver solder is harder than brass so you will need to take care with filing to shape that you don’t take any of the brass away with the file, if you have a lathe you can profile to shape more easily.