Hornby GWR HALL R761 Driving wheel rim problems

[robcat]

Hello

Can anyone help with a problem with metal rims which have come off the driving wheels.  GWR 4-6-0 Kneller Hall Hornby OO Gauge R761 (made 1978)

This loco has been in storage for many years, since 1984, in its original box, and was hardly  used since bought new in 1978.

I checked it recently and found that 4 of the wheels had loose rims, which came off the wheels easily.

Can these be put back on and how can I do that?  I wasn't sure about glueing on  because of spoiling electrical conductivity if that applies and I don't know how they were originally fitted.

They appear to be metal rims on metal wheels

Any ideas please?  I would like to  service the loco  and get it back up running as a vintage model in original condition.

The body condition is excellent.

[What About The Bee]

Hello @robcat

Ordinarily, I would say that these parts should be a light interference fit.  The wheels would have just slightly larger outer diameter (1 or 2 thousandths of an inch) than the inner diameter of the rim.  The parts would be pressed together.  On a real locomotive, a temperature differential is used to expand the rim with heat.  But as the rims are loose under the same temperature regime on your locomotive, there is not an interference fit.  Hmmm

A product like Loctite 603 is used to bond cylindrical parts (like pins in bores), where an interference fit is generally not desired.  With your recognition that a bonding agent may interrupt continuity, a dab of electrical conductive paint across the two will preserve the electrical path.

So before doing anything, you should understand the electrical path.  Where are the wipers?  Do the wipers touch the rim? If so, continuity to the wheels is irrelevant except for a short.  Do the wipers touch the wheels?  Yes, conductive paint will be needed (or similar).  Do the wipers touch the axle?  You must have an insulated wheel to prevent a dead short.

Once you know the electrical path, an informed plan can be developed.

Bee 

[ColinB]

I think they should press back on, I think it is an interference fit. So you need something like a vice to do it. The biggest issue is getting them on squarely. I had never thought of the glue issue but I think you are probably right.

Edited May 4 by ColinB

[What About The Bee]

I agree Colin, should be an interference fit.

Bee

[Rana Temporia]

I have had this problem now and again usually with later ‘Nellies” but also with some other locos. For some reason all the tyres fell off a Duchess I had while a second identical loco never had any problems. It could be down to the castings being not quite right. maybe a bad day in the factory with some impurities in the mix and the castings shrank a little more than expected, just enough to cause an issue? I would just push them back on and if you have a back to back gauge I’d check that when you do it. 

[81F]

I too have had the same problem with a GWR King. Unfortunately it kept falling off so I eventually had to replaced it. If looking for parts remember Hornby locos shared many parts with other types so just don't restrict searches to Hall wheels.

[Rana Temporia]

I think the old style Hall wheels were the same as the B12 ones. 

[Going Spare]

The rims are likely to reseat simply by manual pressure but if you decide that replacement is unavoidable, the wheels you need are 2 each of insulated X964BK, non-insulated X965BK and semi-flanged for centre axle X967BK.  These should come ready to fit but if X964 and X967 are missing insulating bushes, add 4 x S8397.  (After 46 years, the existing insulating bushes may have degraded and need replacing to avoid the insulated wheels coming in to contact with the chassis block.) Peters Spares have all in stock.  As the axles pass through the chassis block, quartering of the new wheels will have to be undertaken on the chassis.

 

[81F]

There are two things to watch for if using B12 wheels - The first  are the flanges and possibly colour. Kneller Hall had slightly finer wheels when it was brought out compared with Albert Hall and the black B12 made only a year or two before. Looking on eBay for parts I find that far more of the old type wheels are available. However, I did use a set of contemporary LMS Class 5 wheels to upgrade an Albert Hall once (although I has to change the crank pin on the set of centre driving wheels, although I assume it is not the centre wheels that are the problem.

[robcat]

Thanks all

reply to Going Spare------  The original service Sheet  86B  shows  (2)X964A,(2)X965A,(2)X967 centre wheels,

Would that be the same as the BK wheels you refer to?  Do you know what the BK part means?

Alan Gibson online catalogue shows  "GWR Hall " wheelset 4872W  are these the same?

[Going Spare]

The BK suffix indicates black wheels - as has been said above, the wheels also fit the B12 loco in LNER green and the N15 in Southern olive green for which suppliers tend to use AGN and OGN, respectively.

The Gibson wheels are likely to be a more accurate representation of Hall wheels, but you would need to check their suitability to fit the Hornby chassis in terms of wheel diameter, axle diameter and crank pin type to take the coupling/connecting rods as well as the availability of insulated, non-insulated and semi-flanged wheel types.  With Hornby using the same chassis for at least three locomotive, there may well have been compromises.  Also, different manufacturers use varying axle sizes, crank pins and methods of electrical pick-up/chassis insulation.

[robcat]

Thank you for that, good information. I will check the dimensions and contact  Alan Gibson for more details. Peters Spares website says they are out of stock

[robcat]

i have just had a thought, if necessary and i had to glue rims on then only four spots of glue around the wheel would allow the electrical flow to continue. the contacts appear to be touching the rim anyway so maybe there is no problem, I will check connectivity between wheel, rim, and pickup contact.