Hornby Class 25 Running Problems

[drgj]

I am still having problems with this loco. I completely stripped the motor, cleaned and lubricated it, etc, but it still won't start smoothly. I turn the controller up and it suddenly starts off but will then run slowly if I turn the controller down. What causes this? Maybe it is just too worn out. Maybe I will try a CD conversion on it.

 

Back in the 70s I bought a brand new one and it was dead smooth at all speeds and made a just a light rustling sound as it ran.

Edited April 15, 2020 by drgj

[34theletterbetweenB&D]

Almost certainly wear throughout the mechanism. The much superior centre motor all wheel drive is the alternative I would suggest, you wouldn't be trying fit new parts to a Morris Marina would you?

[drgj]

There are plenty of people still fitting new parts to Morris Marinas!  In the case of my class 25 I think you are correct.  

[DCB]

There are only about 350 Morris Marinas left on the road and almost all are pampered and enthusiast owned so its a bad analogy.   It's difficult to get half decent starting out of these old high geared ring field power bogies and the old controllers used various devious tricks to combat it like starting as half wave and changing to full wave as speed increased on the "Westminster" controllers, arguably the worst controller ever made, to full voltage "Boost Buttons on some H&M controllers.  Just flick the button momentarily and off it went. 

They seem to like PWM for starting but then sound absolutely horrible.

 I did some fiddling with an entirely impractical AC/DC controller Where it started as AC but then one half of the wave reduced as speed rose until it became first full power half wave and then full wave. Luckily I never tried it on a Coreless motor but starting and low speed was impressive.

 

[drgj]

Thanks, David.

 

[roythebus]

Wheels clean? Commutator clean? We ran loads of these motors on the MRC's New Annington layout in the 1980s and never had problems with them.

[34theletterbetweenB&D]

4 hours ago, roythebus said:

... We ran loads of these motors on the MRC's New Annington layout in the 1980s and never had problems with them.

But if you still had those same locos now and they had been run regularly over the 30+ intervening years, how do you suppose they would run? Mechanisms wear out, simple: the point about the Marina - and any other mass production car of that generation - is that practically none of us are using them as everyday 10,000 MPA+ hacks, and much the same applies to our little locos. Time to move on...

[drgj]

Roy- I cleaned everything carefully.

 

34- this loco is well used!

[drgj]

No. I have done everything possible as regards maintenance. One thing I notice is that it is as if the magnet is too strong as I turn the motor armature by hand.  

 

Dave

 

 

[34theletterbetweenB&D]

Just hunt around for a s/h Bach 24 or 25 mechanism at a good price, hollow out and stuff the Hornby body with it. Instant running upgrade. Unlike stuffing mushrooms this is worthwhile.