RobBrooks1 Posted July 8, 2020 Share Posted July 8, 2020 Hi, Just a quick question. I have a Hornby Britannia Oliver Cromwell which was bought in 2018 a part of the 15 Guinea special set. The loco is DCC sound chipped with a Wheeltappers Zimo sound file, fire box lights and front lights Until recently it easily pulled 6 Mark 1 Bachmann coaches round the layout at reasonable speed with no issues but since using it again since a couple of weeks ago, it's wheels slip in certain areas around the layout and it does not grip the track as well. The track has been cleaned with track magic and the all the decoder sound functions work. Any suggestions please on how to sort our the drop in performance? Link to post Share on other sites More sharing options...
RMweb Gold The Johnster Posted July 8, 2020 RMweb Gold Share Posted July 8, 2020 Lube on the driving wheel surfaces? If so, obviously clean the wheels which you sort of have to do to determine if it is indeed lube on the driving wheel surfaces, but a deep clean of a stripped down chassis, followed by sparing re-lubrication, may be advisable to prevent the problem recurring. Link to post Share on other sites More sharing options...
DCB Posted July 8, 2020 Share Posted July 8, 2020 You clean the track, the loco does not grip as well as it used to. I try to schedule track cleaning for the end of a session to minimise the problem and don't clean it very often either.. A bloke did some tests in the old Railway Modeller mag maybe 40 years ago and found his cast metal bodied 4-4-0 nearly doubled its adhesion on rusty track compared to scrupulously clean, the dirtier the track the better it pulled. We get this all the time, most of my locos are loaded to their limit and they steadily slip more as a session progresses. I try not to clean the up gradients at all, the slipping wheels clean the rails. The adhesion is worst with spirit type cleaners but even the good old abrasive track cleaners smooth off the rail surface and lose some adhesion. Oil also can accumulate after servicing stock. A nice clean white handkerchief is ideal for cleaning oil off, press it firmly against the rail head and drag until thoroughly blackened and then find a clean bit of hanky and repeat. Bit of old shirt or bed sheet can be used if your partner does the weekly wash and gets upset when you use hankies as oil rags. Our old Triang Brit, "Vulcan" shifts 24 Mk1s on the level on steel track and around 12 on Nickle silver, it has some lead in the smokebox and some low down in the firebox but not stuffed to the brim so I guess there is space for some lead even in a DCC Brit which would help. The older tender pickups had as much drag as two coaches, I improved a County, Black Five and a 9F by deleting the pickups, I had to with the 9F the chassis crumbled to dust, well chunks about 2mm square. A 1980s class 47 trailing bogie frame slotted right in. Wheels grip on the gauge corner of the rails not the top, Full size rails are canted inwards and the wheels are coned to match giving a wide contact patch, models tend to run coned wheels on flat top rails giving a very narrow contact, ideal for power pick up, poor for grip. No good to you but I find pre RP 25 Romfords grip code 100 disproportionately better than other tyre profies. I suspect adhesion is better on code 100 than 75 and I would love to know how bullhead rail compares. Link to post Share on other sites More sharing options...
34theletterbetweenB&D Posted July 8, 2020 Share Posted July 8, 2020 4 hours ago, RobBrooks1 said: ...Until recently it easily pulled 6 Mark 1 Bachmann coaches round the layout at reasonable speed with no issues but since using it again since a couple of weeks ago, it's wheels slip in certain areas around the layout and it does not grip the track as well. That will most likely be the tender, Hornby pick ups can go super draggy after a year or more of regular operation. On the tender wheels this means the brakes are on with a vengeance, even worse than the effect of the inside non-bearings. Disconnect the tender, and see how free rolling it isn't... (My usual fix is to reshape the pick ups out of wheel contact, the locos pick up perfectly well off their driving wheels.) I have been posting about this effect for years, but it seems very few people run their Hornby sufficiently to see it happen. Link to post Share on other sites More sharing options...
RobBrooks1 Posted July 8, 2020 Author Share Posted July 8, 2020 Think it is down to the track. I had a look at the connecting rods on Oliver Cromwell and one of the nuts was coming loose. I tightened it up and also cleaned the pickups next to the driving wheels. I also looked at the tender wheels as suggested which were free wheeling. The performance was slightly better . My other Britannia behaves the same so I guess it is down to a track issue. My Twins 1000 diesel pulls the same rake of coaches better but I believe it could be track issues. Link to post Share on other sites More sharing options...
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