Rapido SE&CR 5 & 7 plank wagons.

[Michael WhitchurchParticipant]

There seem to be 2 issues with these wagons when attempting a conversion.

1. These wagons come with Rapido’s own strangely dimensioned version of a top hat bearing, basically a pyramid of metal loosely fitted in the plastic bearing cup of the underframe.

2. The axles (with slightly undersized wheels) are a 26mm long 2.5mm x 1.5mm shouldered version with the step obviously giving automatic BtB in OO gauge.

My solution;

Whilst being initially optimistic of a straightforward drop in conversion due to the 26mm axle length, in my opinion there is far too much axle slop if this is carried out, therefore a plan b is needed.

Basically a method of bringing the top hats closer together is needed, so, out with the drill (depending on which brass bearing you use) and 4 waisted brass top hat bearings, mine were AG I think, drill into the axlebox moulding, there is enough flexibility in the plastic to fold it back to allow a parallel hole to be made, drilling deep enough for the waisted bearing to fit in the hole and for the flange to sit flush with the inside of the axlebox face, glue in the bearing and this then allows a 26mm axle to fit comfortably in the underframe.

From my personal soap box, why do some manufacturers decide to totally ignore what has now become an accepted standard of axle dimension and make it even more difficult for those of us who aspire to a higher level of modelling standards, I don’t expect that manufacturers overly consider the small minority of us who choose to be awkward sods, but working to a standard would help and the manufacturer would benefit from positive publicity, but at least Rapido haven’t descended to the high levels of incompetence which Accurascale and OxfordRail have managed to consistently achieve in this area, or at least not yet!

Mike.

 

[73AParticipant]

Thanks for the helpful advice Mike.

Do you think it is possible to use the Knowle tool to drill the parallel hole rather than folding back the axlebox moulding?

[Michael WhitchurchParticipant]

My original idea was to use the Knowle tool as it seemed the easiest way to go, but, in my guesstimation the V in the plastic axleguard is too wide and deep to allow a sufficient depth of hole to be drilled to satisfactorily support the use of the flangeless bearing, hence my use of waisted bearings.

I have tried unsuccessfully to upload a photo to show my finished article, so I hope my explanation will be sufficient.

Interestingly, since postulating my theory about these wagons on RMWeb, a few members have said that they have dropped AG wheelsets in without any modification and with an acceptable amount of slop. This either means I am too fussy about the amount of slop I will accept but is OK to others, or, I have had a couple of rogue wagons with excessive moulded holes, but in my opinion, without modification the axles are like a dick in a bucket.

As with all conversions try the simplest option first to see if it works for you before diving in and committing scalpel to plastic!

Mike.

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[73AParticipant]

Thanks for the explanation Mike and for pointing out the postings on RMWeb.

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