Bachmann split-chassis axle repair method

[Atlantic 3279]

As requested by Mick B! I know that some of this might sound crude, fiddly, or downright unfeasible to some, but I can assure you all that I've tried this several times with successful lasting results:

When the ends of the plastic middle of the axle (or the "muff" as it is sometimes called) have split, or the whole thing has split in two along its length, and the wheels have gone wobbly and possibly lost their quartering....

1. Drop the chassis-bottom keeper plate (or do whatever else is required) to release the wheelsets.
2. Find, identify, degrease, and match up (i.e fit together dry) the pieces of the axle(s), WITHOUT fitting the wheels into the square sockets in the axle ends.
3. With great care to exactly align any broken bits of axle, use tiny spots of superglue to intially/temporarily hold the axle(s) in one piece. Don't try to simply refit the wheels permanently at this stage in the hope that this much will "do", as the axle will probably quickly split again.
4. If the axles have narrower ends and fat middles, find the size of (say) K & S brass tubing that JUST fits over the narrow ends of the axle and is no fatter externally than the bosses (or stub axles) on the backs of the wheels, and carefully saw off some narrow rings (say 1mm wide at most) from the brass tube, de-burring the cuts thoroughly. 7/32" brass tubing rings a bell in my memory, but you'll have to check as not all Bachmann (or Bachmann style) set-ups appear to be the same, older ones especially may have slimmer axles and bosses.

IF your axles are the same diameter over ther whole length, then the brass tube chosen needs to just fit over the axle but again should be no fatter than the wheel bosses.
5. If your axles have the fat middle bit, then see if the fatter part of the axle is so wide that the wheel bosses have to push tight up against it in order to set the wheels to gauge. Often it is narrower, and with the wheels pushed on to gauge there is still up to a millimetre of the slim part of the axle exposed - if so, you can now jump ahead to step 7. If your wheels push on tight up to the fat middle part of the axle, or almost so, you will have to deal with step 6, below

[mick b]

Many thanks for the info

[Atlantic 3279]

6. Set the temporarily repaired axle up in the chuck of a laithe, or improvise a laithe with care using an electric drill well clamped-up in a "Workmate" style workbench. Spin the axle and use a small fine file to gently trim back the shoulders of the fat part of the axle so that you will have a gap of about 1mm between the fat part of the axle and the rear of the wheel boss / stub axle. Don't reducce the diameter of the already thinner end part of the axle - remember that your ring of brass tube has to go on as a snug fit, as does the wheel!.

7. Put a LITTLE quick-set epoxy around the shoulder of the axle and push one of your brass rings into place. Do this to both ends of all damaged axles. If your axles don't have shoulders and fat middles then work out how far the wheel bosses push on, and apply the epoxy and brass rings just inboard of that position.
8. When the epoxy securing the brass rings has gone off, smear some more freshly mixed epoxy onto the square pegs and sockets that locate the wheels into the ends of the axle, and refit the wheels to the axle, CORRECTLY QUARTERED, at the correct back-to back gauge.

9. When that epoxy has gone off too, clean away any that is evident on the bearing face of the wheel boss / stub axle, or on the outer surface of the brass ring, check that the wheelset will fit and rotate freely in the axle hole in the chassis, and then put your loco back together.

[Atlantic 3279]

There's the full story with pictures now Mick. I hope it helps. BRM have had a fuller better version of this available for publication for some time. Maybe "make do and mend" methods don't sell magazine copies, or perhaps they would rather we all bought more brand new locos and chassis, or Comet conversion kits? I have better uses for my money........

[mick b]

I agree with you , if its mendable why chuck it!!

I am restoring a much abused and very cheap Silver Fox bodyshell sourced off ebay at the mo , it will be pulling my Silver Jubilee Set when sorted along with my Hornby A4 Quicksilver which I already have.
Good fun especially rewheeling the Loco drive chassis another ebay pick up with correct colour wheel sets and valve gear . Just need to find another Grey A4 tender for it too pull too !! Anyone got a spare ??

thanks again

Mick

[Atlantic 3279]

PS if a geared axle has only splits in its ends, I'd be initially tempted to assume that the gear in the middle will be chunky enough to stay in one piece so long as the provocative "prying action" from rocking wheels is eliminated. I think in this case I would just try epoxying the cleaned wheels back into the axle ends, squarely, quartered, and to gauge, and forget about the fiddling around to fit the brass rings. The wheel-boss after all has some effect as a bracing collar around the end of the axle, so long as it is made a snug steady fit by the presence of the epoxy.

[mick b]

I was going to ask as to how to mend the geared axle.I will try that as it is only split on one side at the mo .

There is still no sign of a new one from Bachmann . It wlll certainly do short term until a new one hopefully appears. If it holds the new one can be a spare with the 8 !! plain stub axles I now have !!

[mistahjim]

BRM have had a fuller better version of this available for publication for some time. Maybe "make do and mend" methods don't sell magazine copies,

It strikes me that MR would be more much likely to think about this kind of article, BRM has always seemed to me to have too high an opinion of itself for such things, IMHO.

[Atlantic 3279]

Perhaps I'll submit it to MR and to RM too then, and see if either of them take the bait...

I'd forgotten that I'd written it up until I started looking for pictures to help Mick last night.

[mick b]

Graeme
Axle araldited and so far so good. 30 minutes after gluing two geared axles arrived in the post !!

[Atlantic 3279]

Is somebody pulling your chain Mick? Either that, or you are paying for previously committed sins - even if, like me, you don't actually know what the sins were!

[mick b]

Use to it !!!!

[Blink Bonny]

I find that Bachmann are usually good at supplying spares - give them a ring first to get some new "Muffs."

BB - Tinkerer inveterate

[Atlantic 3279]

I believe that was where Mick started, but they sent him the wrong parts so many times that he started to look for alternative solutions, hence my contribution

[jukebox]

I've just followed these instructions and revived a Bachmann B1 that had perished centres, and wanted to pass on my thanks for sharing the technique!



I used K&S #130 7/32 for this work - as you said, it may differ for others.

But once again, cheers for a most useful discussion.