Why does a wheelsets back to back move?
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Why does a wheelsets back to back move?
Hi all
We have all been there. Find a wagon or item of stock starts falling off only to find the back to back has gone out when it was fine before. I am not on about the obvious occurances where a wheel is loose but those times when it all seems solid. Anyone know why this happens?
Cheers
Jim
We have all been there. Find a wagon or item of stock starts falling off only to find the back to back has gone out when it was fine before. I am not on about the obvious occurances where a wheel is loose but those times when it all seems solid. Anyone know why this happens?
Cheers
Jim
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Re: Why does a wheelsets back to back move?
but those times when it all seems solid.
Its not as solid as it seems
Whenever running on curved track or through turnouts there are sideways forces applied to the wheels, little and often wins out in the end.
Regards
Keith
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Re: Why does a wheelsets back to back move?
Try blobbing super glue onto the axle after setting the BtoB.
Tim V
(Not all railways in Somerset went to Dorset)
(Not all railways in Somerset went to Dorset)
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Re: Why does a wheelsets back to back move?
Tim V wrote:Try blobbing super glue onto the axle after setting the BtoB.
I rather doubt whether the super-glue would be able to get in between the axle and the wheel centre, even by capillary action.
I suspect that Keith's suggestion is the only practical answer - check the back-to-back on your wheels regularly.
Some makes of wheel seem to be more susceptible to slipping on the axle than others. I get the impression that Kean-Maygib wheels are pretty tight on their axles, whereas Ultrascale wheels do seem to be more prone to move.
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Re: Why does a wheelsets back to back move?
Indeed
My experience is superglue makes no difference at all.
Cheers
Jim
My experience is superglue makes no difference at all.
Cheers
Jim
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Re: Why does a wheelsets back to back move?
I suspect that Keith's suggestion is the only practical answer
I didn't make any suggestion, I was answering Jim's question, ie "why does it happen?" not "how can I prevent it?"
Cheers
Keith
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Re: Why does a wheelsets back to back move?
My experience is that super glue does make a difference, notice I said a blob of glue, I don't expect it to work in by capillary action. I aim for a fillet of glue between axle and wheel, the gel types work better.
Tim V
(Not all railways in Somerset went to Dorset)
(Not all railways in Somerset went to Dorset)
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Re: Why does a wheelsets back to back move?
Tim V wrote:My experience is that super glue does make a difference, notice I said a blob of glue, I don't expect it to work in by capillary action. I aim for a fillet of glue between axle and wheel, the gel types work better.
I'm in the same camp as Tim. A *small* fillet in there seems to work well for me.
I can't see any reason why it *shouldn't* work as it's a physical "obstruction" to the b-to-b moving inwards.
Flymo
Beware of Trains - occasional modelling in progress!
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Re: Why does a wheelsets back to back move?
Flymo748 wrote:I can't see any reason why it *shouldn't* work as it's a physical "obstruction" to the b-to-b moving inwards.
Because they can also move outwards?
Will
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Re: Why does a wheelsets back to back move?
That's true and thinking about it they tend to go to wide over too narrow.
Cheers
Jim
Cheers
Jim
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Re: Why does a wheelsets back to back move?
Will L wrote:Flymo748 wrote:I can't see any reason why it *shouldn't* work as it's a physical "obstruction" to the b-to-b moving inwards.
Because they can also move outwards?
True... But I've stopped 50% of the range of possible movement
And that extra little bit of "stiction" might just stop them from wandering outwards. I nothing else, it makes me feel (in a very English way, as I'm currently reading Jeremy Paxman's History of the English) that "Something Has Been Done"
Cheers
Flymo
Beware of Trains - occasional modelling in progress!
www.5522models.co.uk
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Re: Why does a wheelsets back to back move?
Flymo748 wrote:"Something Has Been Done"
What a wonderful antidote to "Getting it all right"!
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Re: Why does a wheelsets back to back move?
Just been reading John Hayes' book, 'The 4mm Coal Wagon' in which (p55) he says he fits Ultrascale wheels. He goes on:
'I always dismantle the wheelsets and reassemble them with Loctite 290, checking the back-to-back dimension with a gauge. This ensures that the wheelsets stay correctly set permanently.'
David
'I always dismantle the wheelsets and reassemble them with Loctite 290, checking the back-to-back dimension with a gauge. This ensures that the wheelsets stay correctly set permanently.'
David
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Re: Why does a wheelsets back to back move?
I've found with Gibsons that a touch of PlasticWeld seems to have a positive effect once the back to back has been set. The wheels aren't actually glued to the axles but they are a good deal more snug.
Cheers,
David
Cheers,
David
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Re: Why does a wheelsets back to back move?
Is there any pressing reason why P4 wheel-sets couldn't be one-piece mouldings, say in nylon? Maybe cost of tooling? It seems rather over-complicated to turn tyres, press them on to moulded centres and then press the wheels onto axles.
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Re: Why does a wheelsets back to back move?
guyrixon wrote:Is there any pressing reason why P4 wheel-sets couldn't be one-piece mouldings, say in nylon? Maybe cost of tooling? It seems rather over-complicated to turn tyres, press them on to moulded centres and then press the wheels onto axles.
How would you propose to fit hornblock bearings to a finished moulding
That would be an ecumenical matter.
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Re: Why does a wheelsets back to back move?
Is there any pressing reason why P4 wheel-sets couldn't be one-piece mouldings, say in nylon?
This has been tried, in various materials in 00 over the years, experience shows that plastic axles are not particularly good and plastic wheel treads are even worse, hence even Hornby and Bachmann provide metal wheels these days,
for disc wheels a small plastic bush in the centre of a metal disc seems to give the best results, Maygib have done some as have Branchlines, and the original P4 wheels also used this method. But its not practical for spoked wheels of decent appearance.
Keith
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Re: Why does a wheelsets back to back move?
A way to help Loctite stay put was described by Chris Pendlenton in his recent article in MRJ. A turned groove on the axle where the wheel sits retained the Loctite; I suspect that a scribed groove or two along the axle (or inside the axle hole) might do. Having said that, I've always used the blob of superglue approach so far.
Philip
Philip
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Re: Why does a wheelsets back to back move?
Horsetan wrote:guyrixon wrote:Is there any pressing reason why P4 wheel-sets couldn't be one-piece mouldings, say in nylon? Maybe cost of tooling? It seems rather over-complicated to turn tyres, press them on to moulded centres and then press the wheels onto axles.
How would you propose to fit hornblock bearings to a finished moulding
For coach and wagon wheels, I was presuming normal, pin-point, outside bearings. I would assume that these would also be nylon. Clearly, a one-piece moulding prevents inside bearings and so isn't applicable for most carrying wheels on locomotives.
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