Clockwork mechanism not working - help needed

[CoalYard]

Hi all, I’ve recently bought an old Hornby number 45 Tank clockwork locomotive set. It looks like it has sat in the attic or the garage for a very long time. I managed to get the wind up mechanism going and loco goes around the track on its own no problem. But when I attach the three or two wagons that came with it it stops and seized up. The spring stops. I haven’t taken the mechanism out or anything yet but would be grateful for any advice on how to proceed to identify the problem and then hopefully fix it! 

[What About The Bee]

Hello CoalYard

Welcome aboard! 

First, understand what is happening.  With only self weight load, the locomotive can move forward.  When we add the load of the waggons, forward motion stops.  

So the tractive effort of your locomotive is insufficient to pull the load.   

So we can fix thIs by adjusting two factors

The insufficiency may come from too much friction in the load, for example the axle bearings may be loaded with crud, or the wheels may not have a smooth surface.  Solution, make sure your rolling stock provides the minimum retarding force.  Clean it as spotlessly as you can.

The insufficiency may come from the clockwork mechanism.  In other words, the force it provides is too low.  Yes, clean this up as well.  Be very aware that taking a mechanism apart is far easier than putting it back together, particularly so because of the spring.  But you should clean this as best you can without taking it apart.  

Lubrication.  You should lightly lubricate all sliding members and axles.  You must lubricate the clockwork. 

Over lubrication may be helpful during cleanup and free up of the mech, but remember to clean that out when done.  Use a lighter petroleum distillate to remove a heavier distillate.

Further, the spring force (the K of the spring) may be reduced from the initial value, due to fatigue or over winding.  The only real solution to this is to replace the spring.  Not for the faint of heart.

Bee

[Rana Temporia]

There are videos online for changing Hornby springs but they have a lot of power. I would recommend appropriate eye protection as a minimum. I wear it for changing OO springs. If yours has been stored in a wound state it will have lost a lot of its strength. The best lubricant I have found for clockwork mechanisms is sewing machine oil and careful application can bring a seized mechanism back from the dead.

As Bee says, check the rolling stock is rolling freely and if not clean it up and lubricate where necessary. Above all enjoy!

Edited July 24 by Rana Temporia

[threelink]

Yes, thorough cleaning and proper lubrication will work wonders even if the spring is fatigued. I shall probably provoke howls of outrage by saying this, but WD40 is an excellent solvent and penetrating lubricant  to free off sticking clockwork mechanisms. However it is definitely not a suitable longer term lubricant. It is good only to free off binding mechs. As suggested by RT a light machine oil should be used when everything has been cleaned and freed off. Many wind up gramophone clockwork mechs have a speed restrictor. It is worth checking to see whether such is fitted to your loco mech and, if so, that it is properly set and not binding. Best of luck in getting your loco to perform better.

[CoalYard]

Hi everyone, thank you to Bee, Rana Temporia and threelink for the the speedy advice - I really appreciate it. I now recall that the mechanism was stored wound up because when I opened it and tried to wind it was wound up to the full. WD40 helped to get it moving and I think the next stage is to clean it up. I've got some good quality clippers oil which I can used for afterwards. I will post some pictures and videos on here to show the process and if you have any comments and thoughts that would be very welcome.