Hornby A2/2 conversion

[Bob JuleffParticipant]

Has anybody managed to convert a Hornby A2/2 to EM gauge yet?

I was just about to get started when I discovered the axles used by Hornby this time are 2mm diameter.  In an earlier thread the proposed solution for converting their loco was to use Gibson wheels with 1/8 inch holes and sleeve them down to 2mm.  I’d be pleased to hear how that turned out or any other solutions using Gibson wheels.

Bob

[Trade OfficerKeymaster]

I suspect that the methods suggested in the earlier thread are the only ones easily available.

I have been looking around for these conversion bushes but AG seem to be the only source. The combination of metric and imperial is not very popular. I suspect AG introduced them as a way of avoiding having to produce new molds for  the driving wheels when some manufacturers introduced 2mm axles.

The only other way is to ream out the axle hole to fit a larger  outside diameter bush but that implies having those tools

I will be ordering a quantity for the stores but delivery will be some months away

John

[Bob JuleffParticipant]

Thanks for the reply, John.  I have received a goodly stash of 1/8 inch to 2mm sleeves so I’ll proceed with these.  Not so sure I could make a decent job of reaming the Hornby wheels…

If anyone has any wisdom to pass on regarding any other aspect of this conversion I’d be keen to hear, especially as the clearances behind the slide bars look pretty slim on the Hornby OO model.

Bob

[Peter HillParticipant]

Branchlines also do 1/8″ to 2mm bushes too.

[Nigel BurbidgeParticipant]

Whilst I haven’t converted a Hornby pacific, I have converted a B17, also with outside valve gear.  There is, as you note, very little clearance and I opted for Gibson wheels (as they are thinner) and filed down the crank pins to get minimum clearance whilst still allowing free movement. Best wishes Nigel

[Bob JuleffParticipant]

Nigel,

Glad to hear your B1 conversion has been successful.  I am guessing your axles were the normal 3mm diameter.  As for my project, I’m currently stalled.  The idea of using the 1/8″ to 2mm sleeves was a non starter as the 2mm hole is a sloppy fit on a 2mm axle.  Not surprising really as it’s designed for a freely running axle rather than a push fit.  A buddy with a lathe has kindly offered to make some sleeves to fit.

Bob

[Nigel BurbidgeParticipant]

Bob,

Yes, the B17 had 3mm axles. Sometimes Colin at Alan Gibson can be persuaded to produce wheels with a 2mm centre.  I have converted a couple of Hornby J15s and an Oxford N7 to EM using Gibson wheels with 2mm centres (as the RTR models have 2mm axles). My other comments on the valve gear hold good.  In addition, you ideally want to go for minimum sideplay tolerance on the front driving axle by inserting washers between the frames and the backs of the wheels. That way you are less likely to have anything fouling.

Nigel

[Graham PriceParticipant]

I had the same issue with the 2mm/1/8″ bush EMGS stores used to have – designed to go with the 9/64″/2mm axle for Triang conversions. They were a good running fit and I used superglue which seemed to work. or you could solder. Not an engineering solution, I know.

[Bob JuleffParticipant]

Nigel,

That’s interesting, I hadn’t realised that Colin produces smaller axle sizes for the variety presented on RTR models.  Maybe if there are enough likeminded Thompson A2 fans, Colin could be persuaded!  Until I looked on his website just now, I didn’t realise how many models had axles other than 3mm.

Yes, I take the point on the restricted clearance behind the slide bars and was planning anyway to have zero sideplay at the front.

Bob

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