Hornby Steam Locomotive Speedo Drives

[H2Eric]

Recently I discovered that the speedo drive on my Lord Nelson (R3603TTS) was detached from the body and as soon as I touched the speedo snapped in half. Hornby provided a replacement free of charge, but it was defective, i.e. bent the wrong way. I returned the model to Hornby along with the defective speedo drive for repair. When it came back it was obvious that the defective speedo drive had been fitted along with a note that it was 'tested OK'. Really! The reason the speedo snapped in the first place is obvious as the end of the return crank is not over the center of the driving wheel axel which results in the 'cable' being bent back and forth with each revolution until it gives up and snaps. The model was returned to Hornby again for repair. Its better now, but not perfect, so how long it will last is anyone's guess. My layout is an engine shed scene so locos do not get a great deal of use, so I would image the answer is not very long. 

This scenario made me look at other Hornby steam locos in  my collection that are fitted with speedo drives. The speedo cable on Duke of Gloucester (R3236) has also snapped. That on Princess Arthur of Connaught (R2447) is significantly bent and looks to be on the point of breaking. 

Other models I’ve found where the end of the return crank is not centered over the axel include Flying Scotsman (R3202) and Coronation class (R3241, R3509TTS, R3856), which results in the cable bending, some more than others. Some of these speedo drives may survive being constantly bent back and forth others may not.

There is obviously a theme here (design fault) which certainly needs to be rectified by Hornby for all future models, which I hope they will act upon.

Meanwhile has anyone else had the same problems. Time to go and check perhaps.

 

[G-BOAF]

I have a few brand new speedo cables in stock and they are normally straight, therefore no right or wrong way. When you attach the crank it is a case of ensuring the cable is bending the right way before applying the tension to it by fitting the crank.

 

[geoffers]

Found speedo drives could cause "limping locomotives" so I snip them off these days. Not too noticeable from 18 inches away.

[atom3624]

One thing I observe is the pivot point should be directly over the axle, not 90' out, or some distance to one side.

It should permit rotation, but appear static / move very slightly only.

It's got a sort-of rectangular shape, which fits over the pin which should locate it correctly - Lord Nelson's is miles out.

This will avoid the speedo being tugged to one side or another.

 

As correctly stated, you can normally 'tell it' which way to hang - up or down, once all is nipped up.

State the obvious, don't over-tighten - you will snap the head off - I've 1 t-shirt on that one!

 

Al.

Edited July 12, 2021 by atom3624

[Steamport Southport]

If you want something a bit more resilient. There you go.

 

https://www.wizardmodels.ltd/shop/locomotive/ls64/

 

 

 

Jason

[MikeParkin65]

I find the only RTR speedo more delicate than the Hornby version is the Bachmann version! For either of them you've only got to look at them 'the wrong way' and they will break! Options are the Comet or Brassmaster versions or the George Dent method using guitar string. As far as I can tell from observing the prototype they actually move very little if at all so when I do get around to fixing my many broken or missing ones I will be locating close to but not actually touching the crank that drives it.

[Michael Hodgson]

The axle end of the real thing would have to move vertically relative to loco as the driving axle bounces up and down in  hornblocks, so some flexibility is required.

[Right Away]

Same here with 30850.

There are photos of other members of the class fitted with AWS equipment but without having a speedometer drive for whatever reason at the time. As a rule, the AWS and speedometers were fitted at the same time;  perhaps Eastleigh was waiting on Hornby!  Mine is in the queue for a change of identity and dating, therefore the “missing” drive cable isn’t a problem.

However, that is not to say the poor assembly is excusable, especially as you’ve returned yours for cosrrection.

[Right Away]

On 12/07/2021 at 11:23, H2Eric said:

 

 

Quote

.... There is obviously a theme here (design fault) which certainly needs to be rectified by Hornby for all future models, which I hope they will act upon ....

 

 

 

This particular component could possibly be one of the final hand fitted pieces of the assembly process and we would assume its fitment would be checked against appropriate illustrations for accuracy. Of my locomotives so fitted, the “Nelson” has been the only one to have this problem. Personally, I would attribute much of this issue to the materials used; moving metal co-existing with flimsy plastic. A change to a more durable material (e.g. soft metal) for the drive cable could offer improvements in this respect. 

 

 

Edited July 14, 2021 by Right Away
correction