Point motors - Bodge of the month, or

[Shed Cat]

"This defies the laws of physics". Cue spooky music......

The layout that I made is about 5 years old and has been stored unused in the garage for the last four and a half years. It has 8 motorised points (Gaugemaster "Seep") driven by a capacitor discharge unit. They all worked superbly 5 years ago.

But when I tried it again recently the points were useless, only feebly moving the switch blades over half way at best. I WD40'd the motor pistons, and even replaced the CDU, with no improvement at all. The input voltage from a new controller at 18v was better than the 16v I used before.

However, in the grand engineering tradition of aimlessly prodding things with a screwdriver, I discovered by accident over a couple days messing around that by just lightly touching the blade of the screwdriver on the side of the piston made the motors work perfectly again.

So I have hung split-washers on the middle of the piston(s) and they all work perfectly. Two brand new motors work perfectly without the bodge washer.

Now, I am gald to have avoided the hassle of unsoldering everything to replace all the motors, but I just cannot understand why this worked. The problem is weird, and the solution impossible, even with my doing A-level Physics, and an degree in Engineering, once upon a time.

I know Gremlins really do exist of course.....

[swisstrains]

It looks like the core of the point solenoid has suffered a thermo-magnetic transference. This is most likely due to the capacitor discharge unit being left in a charged state when the layout was last used (5 years ago) and the layout having been stored in a room where the temperature has regularly cycled.
The screwdriver blade and the split-washers are acting as sacrificial balancing components which restore the non-magnetic equilibrium of the solenoid core thus making it operable again.
If it isn't that....I don't know what it is.

[Shed Cat]

Wow ! Thanks! - I just knew it was something like that all along.

Looks like "sacrificial balancing components" is going to be my new Google "search phrase of the week".

[swisstrains]

Joking aside. It's weird, isn't it?
It will be interesting to see if the motors carry on working or if you are able to remove the washers at a later date.