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Discussion Starter · #1 ·
We got my son a Virgin Pendolino set for Christmas. It's all wonderful except for one thing - it appears that the rear bogie of the power car keeps derailing. It usually happens on points, sometimes (depending on direction) at low speed, even a crawl. I've been experimenting this morning with inclines for a future layout, and it also would go on the uphill round a 2nd radius bend (not sure of precise angle, but I'd guestimate 2 degrees, and it would happen at a constant angle as opposed to a change in elevation at either end). On several occasions it would derail on a simple (if relatively abrupt) stop! No other wheel assemblies seem to cause a problem, just this one.

Fiddling with it, the rear bogie just seems less free than any of the other wheel assemblies, including the front of the power car. Might I have a defective unit? Or is there an adjustment that can be made? Obviously I'm not too keen on replacing the entire set if there is just one bogie issue, but what is the procedure for this sort of thing?
 

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The usual thing to check first is the distance between the backs of the wheels of the bogie that is derailing. I don't remember what the correct range is but you could compare it to bogies that are ok. If the distance between the backs of the wheels is out of range, there will be problems. Too small and the flanges will catch on the guide rails at points.

David
 

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Thanks david - I just checked, and all looks ok on that score. The dummy power car is 15mm, the front of the power car is 16mm and the suspect rear is 15.5mm.

I did a load more tests - I think it is a jolt going up the incline when the whole 4 car train started the rise that caused a judder (when the DCC extra uphill power kicks in?), which in turn caused the wheel to derail under strain, and it only became painfully obvious later on the points at the top. I spent some more time smoothing the incline and that really did seem to help - by the end of the session the whole 4 car unit was roaring up and down at a very healthy speed with no problems. In the end, I figured much of my issues could be down to temporary track arrangements - not tacked, imprecise test inclines, too quick to full incline % etc etc.

Despite that, I'm still a little suspicious though - whenever there is a problem it is always that bogie that goes without fail. It seems to me that logically either this is because of weight and loads that this is the weakest link in all Pendolinos and therefore always the first bit to go under any strain, or there is something up with it. Has anyone else experienced the rear power car wheels being disproportionately prone to derailing?
 

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I had a similar problem with HST Mk3s earlier today in fact - half an 8 coach rake left the track after derailing on a track join where I'd not put it back together properly (temporary track arrangement, not tacked down). At higher speeds little imperfections have more dramatic consequences... There was a pronounced 'click' as each coach passed over the join, and after a couple of loops at high speed, a coach in the middle of the train bounced, and that resulted in all the trailing coaches derailing too.

Another derailment problem with the same rake was caused by the hook-couplers between the end coach and power car getting tangled when going round bends. Happened to any coach in that last-but-one position in the train. The only solution was to take a hook off the coach and leave the one on the power car. Probably not much help with the Pendolino as it's a different coupling mechanism isn't it?

Just a thought if the problem reoccurs, see if it happens if you run the train in reverse. To be fair to the rear power car you'd have to turn the whole train around.
 

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Discussion Starter · #5 ·
Thanks Paul. I'm fairly sure that the problem happens in one direction only - yesterday it was only really when pulling, but a couple of days ago I thiiiiiink it was the other way around over a set of points. And as you say, the Pendolinos couplings are a different design - I'm a little suspicious of them actually since twice the train has come apart on its own, and often it needs very little pressure to break the unit.
 

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Back to back wheels should be somewhere between 14.4 & 14.8 mm - too tight & they will get stuch at the frog between wing & guard rails - too big & they can hit the frog point if the guard rail does not keep the wheel away from the frog point.
 

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hi I am new here, but I also bought a Virgin pendilino, the wheels clip in to a piece of plastic, if you are very careful with a small screwdriver you can pop them back in to place

First check them all to see which set of wheels isnt running smooth, then (very gently) adjust

Regards Pluto

Signature to be added soon
 

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Sorry I have just re read my post (new at this)

The pendolino has fixed wheels set on axles clipped into a plastic bogie, the end of each wheel has a cone that click fits into a recess on the bogie.

If you are heavy handed with them (or a child playing at Christmas)
the wheel axle assembly can be forced up into the bogie dislodging it from its recess.

As I posted earlier the best way to reposition the wheel axle assembly is to carefully manipulate it with a small screwdriver until it clicks back into place.

Trust me, my daughter has dislodged three axles already (or was it me playing)


HAPPY NEW YEAR ALL

Pluto
 

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I forgot to mention that if it is the drive or dummy car, care should be taken to ensure the contacts are not bent and are contacting the wheels
 

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QUOTE (Sol @ 30 Dec 2008, 03:53) <{POST_SNAPBACK}>I use a gauge , remove wheels from the bogie/wagon & gently twist the wheel on the axle in either a pulling or pushing motion.
For a gauge, C&L have one http://www.finescale.org.uk/show_page.php?...ca218a601d932#i,
the HO NMRA track & wheel gauge is ideal as well http://www.nmra.org/standards/sandrp/rp2.html ,
DOGA sell one http://www.doubleogauge.com/shop.htm

*** Oi Sol... you forgot the only polished brass ones with a handle :). Available in 14.5, 14.75 and 14.85 (for finescale/Gibson wheels).

Richard
 

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The clue to one of your derailment problems is the word 'abrupt' when stopping.

If you stop a Pendolino too sharply, it will always derail the set of wheels on the motor, as they have rubber tyres.

As you have read here, and in other parts of the Forum, coaches do not like to be sent in reverse. The slightest track misalignment sends them off, and the couplings are prone to jamming.

I had the same problem recently as 'Paulrelf' in that one of the track fishplates was not connected properly. In the normal direction everything was fine, but when I reversed a train, which is very rare, it derailed because the track was slightly higher in that direction.

AlanB
 

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Discussion Starter · #14 ·
Thanks one and all. Yesterday I reassembled the original track, and the train did derail on a set of points on the same old bogie. A minor rejig of the track either side and the problem completely disappeared - so yes, totally agree that the train is just very sensitive to track alignment. Have to say, when the track is just right, I've not had a problem in either direction though, even at a fair old lick.

Thanks too alan for the observation about the motor wheels - it must be the weakest link I guess. If I get further issues I'll be brave and investigate adjusting that gap!
 

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Discussion Starter · #15 ·
Ressurecting my old thread! A year on, and I still have some issues with the Pendolino. I think this time I've definitely found a "fault" - at least what's causing our latest derailments.

The problem happens when pushing all cars round a 2nd degree bend. Without fail, the power car derails at the train end round this bend. This time, no amount of track fiddling / tacking can make it better - only a third degree bend solves it, where the angle is less acute obviously.

After endless sessions, I finally located the problem. When pushing, the power car and adjacent carriage actually come into contact on this bend. As the carriage straightens out, the inter-carriage concertina thing (excuse the terminology!) juuuust scrapes the power car's inter-carriage concertina thing. It then more conclusively knocks the edge of the carriage itself, causing the wheels to derail.

I've had a look at the underside of the carriages, and the mechanisms aren't jamming - they seem to be working well. It's just that, when pushing, the two carriages are just physically too close by a millimetre or so. Does anyone know of any way of adjusting this gap? I'll be honest, I'm not brilliant with this sort of thing, if necessary I'd get it fixed by someone if it was a remotely tricky job, or else I'm sure I'd permanently wreck it!

Thanks in advance for any advice.
 

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I had a similar problem with a Fleischmann "push pull" set a while back when pushing - the solution was a little extra weight in the control coach & a little silicon lube' in the touching corridor connections.
 

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Discussion Starter · #17 ·
Thanks Brian - I'm a little wary of adding extra weight as the layout involves an incline, and don't really want to use lube as its a set for my 10 year old son (sounds potentially messy!). Anyone else any ideas for increasing the gap between carriages?
 

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The weights I used were just a couple of wheel ballance weights as used on alloy wheels - the lube was just a "touch" (many household polish'es use silicone), but I do see your concern.

You could just try the weights taped to the top of the unit.

I'm not too familier with the coupling arrangement on the Pendolino, but I'm sure there will be someone here that is !
 

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QUOTE (many household polish'es use silicone)
One of our plastic curtain tracks had become very difficult to slide. A quick blast with a furniture polish spray and it was transformed to an easy to use, gliding unit. I guess it was the silicone.

David
 
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