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Why does my model train keep stopping?

Some of the reasons that your electric model trains keep stopping:
  • Dirty Track - Poor condition dirty track reduces conductivity with your trains wheels
  • Dirty Locomotive wheels and / or pickups  - A very common cause of failures
  • Overheating or tired motors - Usually found in older mainline / lima / triang-hornby locomotives
  • Incorrectly wired points - Crossovers and reverse loops can be tricky and can cause short circuits
  • Poor connections to track - The most reliable connection is a solder joint
  • Overload Conditions - Running more than one loco at once or older locos can draw more current

Here at MPB Model Supplies we have met all these problems in customers locomotives coming through our workshop and been able to resolve all of them for our customers. Mike our owner has had over 45 years experience of railway modelling and oversees the workshop.

Dirty track 

Old Steel track is bad for rusting, once it does start to rust then you have two choices:
  1. fine emery cloth rubbed on the running surface every time it rusts, you will be wearing down the rail
  2. replace it with modern nickel silver
Both steel and modern nickel silver track suffer from is a film of 'dirt' that builds on the running surface. This dirt includes:
  • scorching as the wheels travel over the rails causing small arks
  • dust that settles on the rails
  • Lubrication off locomotives
  • Oxidation
If you take a sheet of kitchen roll and rub the rails it is likely  to have black lines on it unless you keep your track clean.

For stubborn oxidation or scorching we use the PECO Track rubber. This is a soft compound reminiscent of a pencil rubber with fine abrasive particles.  

You can use methylated spirits on a lint free cloth to clean the surface of the rails. A better choice would be a purpose made product, we use a liquid cleaner called Track Magic

If you can reach all the track on your layout then regular cleaning would be advised. We find our layouts need cleaning after 5 days of running.

Dirty Locomotive wheels and / or pickups

Most locomotives that comes in for repair with poor running suffer from this problem. The wheels pick up dirt from the rails and  through oxidation and over lubrication.  

Dirty wheels and corroded pickups account for 90% of the non runners we see in the workshop. To start cleaning the wheels and pickups we use Track Magic which comes with a micro brush.

If that is not enough we remove the body from the locomotive and apply power to the motor. Then we use a glass fibre pencil to clean the wheels as they rotate.

Phosphor bronze strip contacts can weaken and need to be clean, forming a good contact with the wheel. As the axle moves the bronze strip should stay in contact with the wheel. If it does not then the contacts may need replacing.

Plunger  style pickups can cause trouble if they have a weak spring or a strong cable soldered on to the pickup. The plungers  should make good contact at all times.

Overheating or tired motors

Common motor faults found on older "open" style motors:
  • Worn out carbon brushes
  • Heat damaged and cracked brush holders
  • dirty commutators
  • decayed spark suppressors
  • Seized bearings
  • Weak magnets
Replacement parts are sometimes available as 'new old stock'. Otherwise you can use salvaged parts, or, modern reproductions.  Remember that on older locomotives that parts become brittle with age so take it gently. 

Commutators have only a thin coating of copper so we clean them with track magic and a small paint brush

The spark suppressors are capacitors which break down with age and can short out. The good news is that modern televisions and radios do not suffer from spark transmissions like the old cathode ray tubes, so they can be cut off.

If the bearings are seized with old grease then careful cleaning with track magic and re-lubrication normally solves the problem. If the bearing is damaged you will need a replacement motor.

Due to the popularity of older models there are firms producing replacement neodymium magnets for Hornby, Lima, and mainline motors. 

With the more modern can style motors they cannot be repaired and must be replaced.

Incorrectly wired points

Short circuits and isolated sections of track can bring your model locomotive to a full stop. When you are wiring points you should ensure that there is a power feed to the toe of the point. The insulfrog style points will switch power to whichever direction the point is set. Electrofrog points need an extra switched connection to feed the frog of the point.

Crossovers between inner and outer circuits need careful wiring and insulated joiners.

If your layout has a single feeder into a returning loop then the outer and inner polarity will reverse as the loop reconnects to the feeder at the point. If an isolated section of track is not used  with switched polarity then the track will short out as the loco crosses the points.

Poor connections to track

Temporary railway layouts can suffer from poor track connections because rail joiners wear and become loose. When this happens the current required to drive your locomotive cannot travel around the track.

Permanent model layouts can also suffer with poor connections with rail joiners over time as the metal surfaces corrode.

Although many model suppliers have power connectors of various shapes and sizes the only long term reliable connection is a good solder joint.

soldering wires feed wires every 1m is a popular solution to poor rail joiners.

Overload Conditions

overload happens when the amount of power drawn by your locomotive(s) exceeds the amount of power available from the controller. some controllers also have short circuit protection.

A locomotive can short out if a phosphor bronze pickup gets caught up between the wheels and chassis, the motor fails or old insulation fails 

If you would like us to look at your locomotive for you please visit our train repairs page

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If you have found one of our articles helpful or have valued Mike’s advice in the past please consider making a small donation as a gesture of support while He looks to re-establish his business in new premisesDonate