Bachmann chassis warping

[highpeak]

Yesterday I went to a railroad show in Marlborough MA and did my best to brighten up the holiday season for a number of traders. I found RP cyc issue 24 that I somehow missed when it came out and paid only the original list price, I picked up the Bethlehem Car Works B&M/MEC Osgood-Bradley combine-smoker which seemed to sell out pretty quickly, and found a brand new, shrink-wrapped undec Spectrum 2-8-0 for a reasonable price, just the job to convert to a MEC loco.

 

Joy turned to aggravation this morning when I took the locomotive out of its shrink wrapped box and put it on my test track. A total lack of locomotion, even though the motor was turning. I then noticed that the wheels were locked solid, rock solid.

 

I started to strip the engine down to see what might be causing this grief, since there was no obvious problem in the valve gear. First sign of trouble: keeper plate was warped. Once the keeper plate was off, there in all its banana-shaped glory was the problem. The chassis was so badly warped that the axle slots had closed up, gripping the axles as tightly as any vice.

 

Anybody else had this issue with Bachmann? I recall all sorts of grief with UK locomotives and warped chassis, a Southern loco as I recall, but I didn't see much about this problem with US locomotives.

 

[alfsboy]

You should be able to get a replacement from Bachmann though I once ordered a decapod chimney and it arrived a good nine months later .Its annoying they are using cheap crud potmetal.

[34theletterbetweenB&D]

In common with every operation using mazak/zamac, sooner or later a melt gets contaminated resulting in the problem you have seen. It was the footplate casting of an early production run of Bachmann's SR  N moguls that had this trouble in their OO range. The problem usually affects a discrete production batch, very likely that other purchasers have had the problem with the item you have bought. Worth approaching Bachmann USA, especially as you know that Bachmann UK made a batch of replacement parts available for the N class problem...

[Adrian Wintle]

I've had the same issue with Rivarossi N-scale steam locos. All three that I own have Mazak issues (including jammed drivers).

 

Adrian

[highpeak]

I sent an email to Bachmann's service department outlining the problem.

 

Sitting on the shelf as a long-term project is a very old Model Die Casting ten wheeler, the casting true as the day it was made. This casting on the other hand looks like it is crumbling, a lot of cracks. I did manage to remove and replace the rear axle, the front one can wiggle a little bit but the middle two are absolutely trapped as the casting has become longitudinally warped, closing up the slots.

The cylinder block is also damaged. One cylinder is still parallel to the chassis, but the other one is bowed inwards quite sharply. Even if the chassis wasn't warped, I doubt the engine would run very well.

I had my doubts about this project because the Bachmann engine is a bit chunky for a MEC W class, but it's about the only way to go if you can accept the compromises. Since neither surviving engine stand any chance of ever running again (one is at Scranton, the other at North Conway), I suppose you could say that this model is at least prototypical in respect of its operability!

[switcher 1]

Next layout - a loco breakers scrap yard(?).

 

(Sorry, couldn't resist.)

[highpeak]

Update: no response at all from Bachmann to the email I sent them, which does not look like customer service to me. Next step is going to be a snail-mail letter.

 

At this stage I am less than impressed with their product, and not at all impressed with their service.

[CraigZ]

From a post that I made yonks ago here on RMweb...back when the Heljan 47s were doing the Zamac warpage thing.

 

Back in my university days when I was studying metallurgy, one of my professors who happened to be a tinplate train collector and restorer told me his theory was that poison Zamac aka zinc pest isn't an electrolytic problem or a temperature problem. It's actually (ready for this?) an atomic problem, a metallurgical problem with impurities as Stephen notes - typically lead, antimony and bismuth. Zamac, like almost all metal, has a 'grain' structure. When liquid metal solidifies, the metal doesn't start freezing uniformly - it begins at nucleation points in many places more or less at the same time. A cubic atomic structure of atoms grows out of each of those nucleation points forming a grain. As the grains continue to grow they bump into each other, forming grain boundaries. When the contaminated Zamac alloy is poured and solidifies, the contaminant atoms are trapped inside the grains...but the contaminants don't like being inside the grains. Through a process known as diffusion the impurity atoms move thru the grain structure heading for the boundaries. As the impurities gather at the boundaries they push the grains apart...which is what you see with the 'poisoned Zamac' that we see in old models that are swelling and crumbling. The long time it takes for the failure to happen is consistent with diffusion theory as well. Is my professor right? Beats me...and I'm not certain that this is what's going on here as these models just aren't that old, are they? But I'm inclined to think the issues with this Bachmann chassis is indeed poisoned Zamac. I was used to seeing this in models that were 30+ years old, not ones less than 10 years old.

Anything you do to the existing chassis will effectively be rearranging the deck chairs on the Titanic...how long it takes your particular ship to sink is the great unknown but it will eventually sink. Your chassis will disintegrate into chunks and dust or at least deform into uselessness. If you can get a replacement chassis from Bachmann that's the only real long term alternative...

 

 

 

[highpeak]

I don't know how old this model is. It was still in the shrink-wrap, clearly had never been opened so it was new, but possibly New Old Stock.

 

Next step will be a polite snail-mail letter to Bachmann with a picture.

[alfsboy]

Wartime Dinky Toys ere plagued by metal disease using less than pure metal .I remember seeing a Dinky ship bowed in the middle quite badly .As it was still in its packing the dealer still wanted a fortune .Of course lead soldiers  also suffered lead rot .Wonder if Hornby suffered from this .In a sense the Chinese are still learning ...slowly .A simple bit of knowledge that they have to learn the hard way as no one is there to warn them .

[highpeak]

The distortion of the chassis left the cylinders out of parallel:

 

This strip of 20thou styrene was a loose fit under the straight edge:

 

 

As Craig said, there is nothing you can do with this, it's scrap. It would be interesting to know how long it had been on the shelf. I can only presume as an undecorated loco it had limited appeal, either that or people wanted the DCC version or something.

 

[CraigZ]

Wow.  Always kind of stunning to see the photos of the damage. 

[highpeak]

To add a postscript to the topic: Bachmann is replacing the engine with a new one. The reason for the delay has nothing to do with them, it took me a while to get around to shipping the defective loco to them. They didn't have any that weren't fitted with a DCC chip so I agreed to a modest up-charge to get a chipped one, which works OK for me since I took the DCC plunge. Only downside is they had no engines for that underrated road, the Undec RR, so I'll have to strip it. But it's destined for some butchery anyway.

Now to start finding bits and pieces to make it more closely resemble a MEC engine.

 

We throw enough brickbats at manufacturers, I thought it worth noting good service. It was interesting though that they had never seen this issue before.

[highpeak]

And a PPS: I am afraid I can't give Bachmann's QA very high marks. The replacement engine arrived today, securely packed though not as nicely as Bachmann's UK offerings.

 

Anyway, I placed the engine on the track and to my dismay discovered that the DCC controller couldn't read anything from the engine. I ran another engine just to check nothing had gone awry with the controller, then tried running the engine with DC. Dead as a doornail.

 

I stripped the tender down and discovered the black wire between the circuit board and the decoder was not connected, the wire had broken off the soldered connection to the decoder. I soldered it back in place and the motor finally came to life.

 

Normally opening boxes and putting engines on the track is the easy bit of this hobby...

[trisonic]

Bachmann USA is  like dealing with a completely different entity to Bachmann UK. Which it is.

I don't own anything from Bachmann USA now - well, just one On30 loco which was a gift - I haven't bothered trying to run it..

 

Frankly most stores around me in New Jersey do not stock or order Bachmann product because of difficult issues they encountered with them in the past. It's a shame really.

 

Best, Pete.

[shortliner]

Bachmann USA is  like dealing with a completely different entity to Bachmann UK. Which it is.

I don't own anything from Bachmann USA now - well, just one On30 loco which was a gift - I haven't bothered trying to run it..

 

Frankly most stores around me in New Jersey do not stock or order Bachmann product because of difficult issues they encountered with them in the past. It's a shame really.

 

Best, Pete.

 

Strange - I have NEVER had any problems with Bachmann , either in UK or USA - They are always unfailingly polite and helpful, like most of the sellers in USA - seriously, some of our companies in UK could learn a lot from their customer service training

[trisonic]

Jack, I've been quoted repeated drive train issues (fractured gears). One store did say that they (Bachmann USA) were fairly easy to deal with but that the issues were just too time consuming.

Personally I hope that it picks up as some of their recent diesel new releases look extremely useful. The big box shifters still stock them, I hasten to add.

 

Best, Pete.