21:39

Welcome to Railway Forum!
Welcome!

Thank you for finding your way to Railway Forum, a dedicated community for railway and train enthusiasts. There's a variety of forums, a wonderful gallery, and what's more, we are absolutely FREE. You are very welcome to join, take part in the discussion, and post your pictures!

Click here to go to the forums home page and find out more.
Click here to join.


Go Back   Railway Forum > Railway Modelling > Railway Modelling

Point motors - Bodge of the month, or

Reply
 
Thread Tools
  #1  
Old 19th November 2006, 22:47
Shed Cat's Avatar
Shed Cat Shed Cat is offline
Senior Member
 
Join Date: Nov 2005
Location: Southern UK
Posts: 1,100
Images: 46
Point motors - Bodge of the month, or

"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.....
Attached Images
File Type: jpg P1010008a.jpg (38.9 KB, 11 views)



Last edited by Shed Cat; 19th November 2006 at 22:51.
Reply With Quote
  #2  
Old 19th November 2006, 23:53
swisstrains's Avatar
swisstrains swisstrains is offline  
Senior Member
 
Join Date: Oct 2005
Location: England
Posts: 4,149
Images: 538
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.
__________________
John …….My Railwayforum Gallery
Reply With Quote
  #3  
Old 20th November 2006, 21:02
Shed Cat's Avatar
Shed Cat Shed Cat is offline
Senior Member
 
Join Date: Nov 2005
Location: Southern UK
Posts: 1,100
Images: 46
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".
Reply With Quote
  #4  
Old 20th November 2006, 22:02
swisstrains's Avatar
swisstrains swisstrains is offline  
Senior Member
 
Join Date: Oct 2005
Location: England
Posts: 4,149
Images: 538
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.
__________________
John …….My Railwayforum Gallery
Reply With Quote
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is Off
HTML code is Off

Forum Jump


All times are GMT +1. The time now is 21:39.


Powered by vBulletin® Version 3.8.4
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.