Class 66 Bachmann Stobart - Consistently Inconsistent

[Truly Amateur Novice]

I have a class 66/9 Stobart from Bachmann (32-977) in OO gauge and it is causing me constant problems.

 

There appears to be no consistency in how the locomotive runs apart from it will de-rail at some point around my layout - especially if it is carrying cargo - has anyone got a similar problem with theirs? Or knows how to fix the problem? It's a fixed continuous run layout that comprises of mainly 2nd and 3rd radius curves and i dont think there is anything complex in the layout for a large model to struggle with.

 

I love the model but it spends most of its time in the box as i get frustrated that it performs badly compared to others in my "fleet" - i have a class 150 DMU that performs so well i almost feel that it is showing off. I aim to get another Class 66 - probably Freightliner livery - but dont want to get it if it encounters the same problems.

[birdseyecircus]

If you have fitted the front bogie plough check that the NEM coupling pocket is not rubbing the inside of it preventing the bogie from moving. I bought the Model Rail EWS/cargo rail and DBS 66101 both of which needed the coupling pocket trimming back by  a tiny amount.

 

Paul

[newbryford]

Apart from the coupling pocket mentioned above, try loosening the bogie pivot screw by 1/4-1/2 turn. Sometimes the bogie can't pivot enough in a vertical plane (yaw?) and the leading axle can derail as a result. Check that the fitted details, such as the AWS magnet on the inboard end of the bogie isn't loose and causing problems.

 

Check where it is actually de-railing. We had one on Blackmill that would de-rail at a particular point, but we eventually traced it back to a dodgy board joint that would throw the leading axle out of line until it finally caught the pointwork and fully derailed.

 

Cheers,

Mick

[34theletterbetweenB&D]

And finally, in addition to the above suggestions which are known trouble spots; if none of these prove to be the cause of the derailments, take a steel straight edge and test the wheels each side to see if all three in each bogie sit correctly on the rail.

 

If the brass bearing inserts are tight in the bogie moulding, this can take on a slight banana shape resulting in only two out of three of the bogie wheelsets being on the rail at any time. Very apt to cause the leading wheelset to climb over the outside rail on a curve, especially under load. If you want to see what is happening most easily, unclip the outer cosmetic frames of the bogies, and run the loco with the wheels exposed.

 

Simple to fix if this is the problem, very slightly enlarge the locations where the centre axle bearings seat until they are an easy rather than tight fit.

[Truly Amateur Novice]

Thanks a lot for the above.

 

As very much an amateur to the hobby some of the above doesn't make sense but i have a father in law that will understand that all and explain it to me.

[Jack374]

I've had problems with 66411 too, I tried loosening the screws as newbryford (Mick) states, and it half solved it. After fully dismantling it (there is no need to do this, I got frustrated), I found one of the wheels and bearings were popped out, but I probably did this when dismantling.

 

So I checked the wheels with a plane mirror and they were ok. I checked the back to backs (distance between the backs of the wheels) with some calipers, and these were mostly fine bar one wheel set, which was therefore priesed apart slightly with some pliers. Finally I took the chance to oil it.

 

Only one spot on one particular (very badly made...not by me!) layout derailsit now. Not bad.

I've heard that Bachmann 66 flanges are very fine, so this could be the problem, and unfortunately there's no solution if this is the case.

 

Hope something in this helps!

Jack.

[tycoonuk]

And finally, in addition to the above suggestions which are known trouble spots; if none of these prove to be the cause of the derailments, take a steel straight edge and test the wheels each side to see if all three in each bogie sit correctly on the rail.

 

If the brass bearing inserts are tight in the bogie moulding, this can take on a slight banana shape resulting in only two out of three of the bogie wheelsets being on the rail at any time. Very apt to cause the leading wheelset to climb over the outside rail on a curve, especially under load. If you want to see what is happening most easily, unclip the outer cosmetic frames of the bogies, and run the loco with the wheels exposed.

 

Simple to fix if this is the problem, very slightly enlarge the locations where the centre axle bearings seat until they are an easy rather than tight fit.

 

Thanks for that info. My sound version of 66411 does the same banana effect as well as the bogies not moving correctly like I think is caused by the ride height.

[David62]

mines is the same!  frustrating to the least!..  i have had to file down two of my standard points frogs as they make the bach 66 step up onto the frog and derail  I can turn it round to the short cab side and it goes through no problem??  then i can bring the loco round to another point and it derails again!!  turn it round again to the long cab side and it goes through no problem???    I have had the body off and all sorts  cannot see any problem apart from both the bogies catching on the body underside when on each turn through Left & right hand points... the style of the bogie shape catches on the underside of the frame.....mainly the tops of the bogies where theres a rise of about 2mm    is enough to catch on the underside  my Hornby 66's dont have this  or derail as much as this one!!    so many  £££'s   for superior Quality eh???!!!

[cessna152towser]

I bought a pair of Bachmann 66s at a closing down sale a few years ago.  They kept de-railing and I soon recouped my outlay by re-selling them on eBay.

Now I have six Hornby and one Hattons 66 and none of these give me any trouble of derailments.

I am wary of Bachmann six-wheeled bogies.   My pair of Bachmann 37s run OK, but my 47 will only run one way round.   If I forget that the driver must be in the leading cab when the loco leaves the fiddle yard then it always derails as it comes out of the first curved section.

[Matt]

I wouldn’t say this behaviour is typical of Bach 6 axle locos - I have around 100 and most are fine. There is a well documented issue with the Bach 66 which can be resolved with a spacer to lift the bogie to body gap slightly as issues can be caused by catching  - oddly not in all cases.

 

The issue with the 47 is not one I’ve encountered but I wonder if could be a back to back issue with the wheels which is occasionally an issue across many manufacturers products?

 

M