A tad unfair if I may say. The J72 had a minor upgrade (from the Mainline version) when it was first reintroduced a fair few year's back, but we all know that things have moved on since then with the introduction of the Blue Ribband range from Bachmann.
The J72 and other split chassis locos continue in production for the time being, in much the say way that Hornby persist with their Ringfield motored diesels, electrics and kettle models, despite their similar move to better quality models. It would be unreasonable to expect both major British manufacturers to simply dump all of their older models.
I've spent some time attempting to fix the fleet of broken J72s.
From taking 3 locomotives to bits, I can see three re-engineered chassis;
the original mainline (683) model has a smaller axle gear cog diameter and is driven from the centre axle.
the 'early Bachmann's version (8680) is driven through rear axle and has a slightly larger diameter cog.
with the later version(2313) they seem to have introduced some quartering. the diameter of the axle is increased to accommodate a square plugged in wheel. This part has suffered the worst split - the insulating cog has split into two pieces.
With these variations it's not even practical to try and make a good one from two( or 3) broken ones as the parts have changed as Bachmann have tried to improve the design.
The conclusions I can draw are that once the chassis break, that's it. you really do need to just go and buy a new one.
I'm going to see what I can get by way of spares for the Bachmann ones - I get the impression that any parts I can get will only be for the latest version of chassis.
If there are problems with fragility, it might be nice if the Bachmann put a spare cog in the box with the loco, I can't imagine that this would add noticeably to the cost of the model and might save us some grief.
I too have examined some chassis - in particular the Bachmann modified Hall. This re-inforces Craig's comment about the later Bachmann J72 chassis being more suspect. Clearly the material used for the thicker axle centre(to take the squared stub axles), or the method of manufacture, does not provide a stable product. If I have to take any chassis apart in the future, even just for cleaning, I will check for this fault as I feel catching it early may extend the life of the chassis.
I have not had an example - yet - where the centre bush has totally split in half, but I have had a couple of bushes be split across in one place. Since this bush does not, except in the case of the geared bush, have to be precisely round, I have used superglue to flood the split(out of the chassis of course), and similarly glued the stub axle of the wheel into the bush. So far this has worked, but as my earlier post mentioned, I don't know how long it will last given the "slippery" nature of the material. Gel superglue may be better, as some measure of gap filling is required, but has anyone tried Araldite or similar?
It is to be hoped that any future replacement chassis for upgraded models are backwards compatible with the earlier versions, and that they do not have similar built in obsolescence. I am not too hopeful, though, given that an 08 shunter has had a split cog on the driven axle.
Are current Hornby products any better constructed to justify their higher prices?
Col> I've spent some time attempting to fix the fleet of broken J72s. >
I'm only saying what I see. I'll admit that I'm looking at it from the perspective of someone who, with my Father, regularly exhibits model railways (so we're probably demanding quite a bit) but those J72s keep failing.
It isn't the only Bachmann locomotive we've had problems with. Other tempremental performers include a couple of V1/V3s, a J39 and an otherwise excellent V2 that 'burbles' as it goes forward.
I'll grant you that things have improved beyond all measure cosmetically, but IME the Blue Ribband stuff isn't 'all that' operationally - when it's good it's good, but when it isn't it's 'orrid. ;-)
Despite what a number of people on this group say about them, we've found that our Ringfield-motored engines have performed superbly over the 7 years we've been exhibiting model railways.
I'm typing this having come back from exhibiting Thorpe Thewles at the Hackworth Society MRC Exhibition, and the
I'm not suggesting that they do, but that J72 is in urgent need of a redesign. Simply buying a replacement chasis (last time we checked, that was the only option) costs nearly as much as a new engine.
Hummm, my son has a Bachmann GWR 57XX with the split chassis, first it lost quartering on the driven axle, then the centre, super glue holds for a while, Bachmann suggested buying a "new" chassis (wouldn't entertain assisting with the cost though, nice customer support atitude when they know its a design fault), but when time permits a Comet chassis will be built and fitted.
PolyTech Forum website is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.