Model Railway Forum

hi has anyone had a problem with valve gear locking up on the hornby flying scotsman and if so how did you cure it mine lock up sometimes and i am having a problem with trying to cure it any help would be most welcome regards bob

If it suddenly locks up, it sounds as though it may be slightly out of alignment. I recall having this problem on an old FS some years ago. With a flat-headed screwdriver, very carefully ease the valve gear. If you can run the loco upside down you may be able to see which part of the gear is sticking. Whatever you do - do it very carefully.

Have a look under the Hornby heading - someone having similar issues with a Hornby 9F.

I used to have the issue with tender drive King classes by Hornby and Lima. They were free running but still had their moments! I was later told that adding extra weight can help. Actually if they had put traction tyres onto the non driven drive wheels it would not have been an issue.
The king classes did not have external walschaerts valve gear so they "Should" have been free'er runners but they still had issues.
Never was a fan of tender drives, and my chief complaint back in those days was that I would spend half the year to a year saving up for my next new loco and then order it to find it was tender drive, as it was a bit "Hit and miss"... As even with the same manufacturer, be it Dapol or Hornby etc; as some locos were tender drive and others were loco drive -and it was rare to see any information (Even in the catalogues) to inform customers which was which.
Today it is rare to see a new tender drive loco which to me is a good thing, though I do admit that most tender drive mechanisms were easier to work on and they did pull well as my kings were the strongest pulling locos I had back then!

I have found recently that tender drive locomotives seem to perform much better when converted to a cd motor.

Recent conversions I have done include 2 × Hornby black 5 locomotives, a GWR King class locomotive, Hornby 9F with the older more chunky 1980s / 1990s valve gear, a hornby 8F motor used in a project, hornby 1980s patriot locomotive & 2 duchess locomotives and they go like the wind.

Another conversionI did was a Bachmann class A1 from the batch which had duff motors which I coupled to a hornby A3/A4 tender drive motor, it was actually the very 1st cd motor conversion I did.

The main issue I often discovered with tender drive motors was the commutator windings snapping and shorting on the metal block aswell as the central gear working loose. With a cd motor conversion, there are plastic gears available which fit securely onto the motor shaft without the need for any glue.

In reference to the valve gear on tender drive locos, as long as the axle bearings are regularly cleaned & oiled ( not too much ) and the valve year also oiled ( again not too much ) the locos will be ok.

Hope this helps.

A CD motor will not cure sticking valve gear.

Hopefully Bob has sorted it out since June last year.

Thats one reason why I sold all my old tender drive locos - A) They just don't run as well as a loco fitted motor. B) They look really silly skidding along the track with the tender drive pushing and the valve gear sticking! C) Many, if not all? tender drive have Traction tyres fitted on at least one set of wheels!

With you there Brian, tender drive and traction tyres, horrible things.

Granted a cd motor won't cure a sticking vslve gear on tender driven loco's, however, as mentioned in my post, light lubrication will cure it.

Another way I put an end to that issue was by fitting motors into the locomotive ( if suitable to do so ) aswell as an appropriate drive gear onto the relevant axle and have the locomotive do the driving instead of the tender and this also will minimise ( NOT Prevent ) the valve gear from sticking and as also mentioned by other members when handling a loco, lift using the body instead of the chassis.

Not sure about the lubrication as most sticking valve gear is caused by distortion.

Moving the motor into the engine is without doubt the best solution, after getting rid of the locos, however this would be beyond the skills of the majority of users of this forum, including me, and I consider myself a reasonable 'mini' engineer.

I was at a swapmeet at Hulme Hall in Port Sunlight and purchased an R398 Scotsman minus tender. It had rusty driving wheels and with that I decided not to have any power collection from the wheels.

As I wanted to get the loco working and had a spare XO4 motor fitted with a neodymium magnet aswell a black worm gear suitable for use with a grey coloured gear ( I will provide a picture later to show this gear ).

After stripping down the chassis, checking all valve gear was still ok ( minor remedial work was required on this ), the entire 2nd driving axle was disassembled to ensure that the bearings didn't get glued to the axle while the superglue was setting the grey gear in place.

While the glue was setting, I set about wiring up a tender from a newer version of the LNER Gresley A1/3/4 locomotives aswell as connecting this to a parcels coach fitted with auxiliary 2 rail pickups on both bogies. These were then connected to the motor once the driving axle and loco were reassembled and the enture consist tested before fitting the loco body. The valve gear was all lightly lubricated and test run off the track to get the lubrication worked in and check for any issues at all power levels.

I am pleased to say that it works and I take your point about it not being an easy conversion to do but I can assure anybody thinking about a conversion like this, it is very easy to do. If pictures are required in order to help show what I did, I will sort those out either tonight or over the next day or 2.