Heljan 47 Chassis issues

[kintbury jon]

First, can I say this thread is not aimed at having a go at Heljan. I have OK'd this thread with Andy.

 

The recent thread regarding the chassis fatigue problems in my opinion was an important issue that needed to be aired. As a result I have 8 Heljan 47's sitting on my layout with the bodies separate to the chassis.

 

Whilst I am aware that there may be no cure to metal fatigue I was hoping that there may be tips that could prevent any damage to future models. Being able to spot the chassis 'going' may well save a few models.

 

It appears the main damage ocurs in the corners of the bodies and at the ends, is there any benefit in filing the chassis at each cab end and the corners so that the body will then fit?

 

We have been shown photo's of broken bodies, does anyone have a photo of an offending chassis?

 

I'm hoping that this could be a positive thread.

[Beacon]

I have had one dud (so far!) which I thankfully managed to save just in time with some minor damage to the body - A Rail Express DRS Limited Edition bought from Ebay. The chassis is in my scrap pile awaiting whatever I can think of to do with it next...

 

In terms of positive advice I have done as you have and now keep chassis and body separate. I found that the first sign of a problem was it becoming ever more difficult to remove the body from the chassis. There also appeared a tiny crack where the warning panel meets the body side at the base of the body. Whether filing it down would have prevented the ultimate problem who knows?

[bertiedog]

I have had one dud (so far!) which I thankfully managed to save just in time with some minor damage to the body - A Rail Express DRS Limited Edition bought from Ebay. The chassis is in my scrap pile awaiting whatever I can think of to do with it next...

 

In terms of positive advice I have done as you have and now keep chassis and body separate. I found that the first sign of a problem was it becoming ever more difficult to remove the body from the chassis. There also appeared a tiny crack where the warning panel meets the body side at the base of the body. Whether filing it down would have prevented the ultimate problem who knows?

 

That the mazak has actually grown in size is telling, it must indicated worse to come, which is the lead oxide or contamination causing the complete breakup, powdering, and eventual disintegrating of the metal. Nothing stops the process or slows it up, the oxide is there and causing the problem.

 

How long this takes is unknown, it may take years, and in the meantime, the only action is to machine away the excess, I would suggest a belt sander and files would be best.

 

The removes pressure from the Plastic shell, and may stabilise it for several years as far as shell breakage.

 

Do not forget it is widening as well, so sand away a bit on width.

 

Once free of the pressure the body cracks can be repaired with solvent, and should barely show after touching up any cracked paint.

 

Stephen.

[bertiedog]

For reference as it was mentioned before:-

There is another answer and that is to have a brass lost wax casting made to replace the chassis, the cost of such a lost wax casting would be astronomic compared to the original cost, and the best approach is still to send back to Heljan for a replacement. A friendly artist who works making bronze figures would have the facilities for such a casting, but as I say costly and a lot of work to turn the existing chassis into a master, and then cleaning up and machining the cast to get it ready to fit. Not for the faint hearted.

Stephen.

[Beacon]

Perhaps there will be a market for something from Heljan similar to ViTrains offering for updating the old Lima models!

[kintbury jon]

I'll probably try filing around the corners of one of them and see how it goes. Beacon - do you have a photo of the offending chassis?

[Beacon]

Don't have a photo at the moment. I could take one but it is unlikely to be until next week.

[kintbury jon]

No worries (or hurries!). I'd be interested to see the effects on the metal. I've been thinking about this for some time. When the original thread came out, I had thoughts of "sell all the Heljan ones and buy Bachmann/ Vitrains" but I like my Heljan ones and the liveries that they're in.

[Beacon]

I've had similar thoughts. I'm not quite sold on the ViTrains offering and would much rather see what options there are with the Heljan ones I already have, especially considering the investment involved in potential replacement.

[Martin_R]

Here are some photos of the chassis block from my RES livery 47 781 Isle of Iona. Chassis has grown in length by just over 2mm plus distorted and cracked.

 

For info I did contact Howes when I first noticed the chassis problem and they were eventually able to supply a replacement chassis once one became available from Heljan.

[Horsetan]

Wow, that is a real time-bomb.

[bertiedog]

This is classic mazak rot from impurities, and because it is inconsistent proves it is, as some are unaffected, due to one batch containing lead scrap and the next casting batch not. Mazak zinc has to be over 99.9% pure, something the makers always knew, but when manufacturers like Meccano used the metal in the foundry and moulding process, lead or other alloys like solder got added as scrap. The same thing has occurred in China.

 

Zamak is the other trade name and fails in the same way, impurities have got in the metal, and the maker is responsible, not a question about Guarantees, if it fails it was badly made, and no age or G/tee expiry can overcome the basic bad material, which should be replaced by Heljan.

[Horsetan]

If you ever come across a book entitled "Poorly Made In China", that may help to explain how and why poor quality comes about....

[kintbury jon]

Thanks for the photos Martin. I'd be interested in knowing whether it will still continue to expand.

[Martin_R]

Hi Jon - first noticed the body was a very tight fit in early 2008 so removed the body just in case and then discovered a small crack in the body! The chassis has continued to distort with a gradually more pronounced sideways bend as can be seen from the photos. The growth seeems to have slowed down but it is still expanding. Looking at some of the immages of damage posted previously my chassis is not the worst by far. Martin.

[Pixie]

I also had a RES 47 from the inital batch (although I can't remember which) which sat in it's box for a number of years. When it came to selling it on last year, I attempted to remove the body from the chassis and having tried all the usual trick it just would not budge. In the end I resorted to grabbing onto the chassis block with a pair of pliers and the whole lot just crumbled. At the time I put it down to me applying a little too much elbow grease but to me it's got a lot of symptoms mentioned above.

 

It's a worrying prospect and due to time it takes to develope I'm a little worried that my Westerns, Hymeks and Falcon could potentially suffer the same. It'll be interesting to see what solution is offered.

 

Pix

[CraigZ]

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 uniformily - 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 the 47 chassis is poison Zamac. I was used to seeing this in models that were 20+ years old, not ones less than 5 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 Howes that's the only real long term alternative.

This has made me decide to pull the shells off my Westerns and Falcon just to be safe. And the more horrifying scenario is that there's only 2 or 3 manufacturers in China making models...the potential is there for other company's products to be time bombs as well...

[bertiedog]

It does concern me, lots of FE production may be affected, but it does typically find itself confined to a particular batch of casting metal, the billets are OK, it is the practice of re cycling the sprues and surplus back into the melt that causes the troubles.

 

Solder gets into the mix, swarf from other metals, dust, and fluxes, all would burn off in a hot steel mix, but this is Aluminium Zinc mix, and the contaminants remain in the mix at the cooler temperatures.

 

The Mazak billets are pure, 99.9% is required for Mazak/Zamak, and it is simply down to bad factory practice at the foundry. Heljan must be fully aware of the issue, pack up and send direct to them in Denmark if the importer will not help.

 

There's no time limit, if the stuff deteriorates it was contaminated, and not of merchantable quality, and should be replaced, or the money refunded, they are simply not acceptable.

 

I was told that the problem was oxide based, the weight of the chassis increases as the oxygen is converting the metal to oxide.

 

The increase is the weight of the oxygen, sounds slight, but can increase weight by 10% if all the metal oxidises. The oxide occupies more volume, which explains the expansion. The bending is due to uneven distribution of the oxide in the metal.

 

Some Zamak can bend without oxide, this is age stress relief, due to bad temperature control in moulding, but rarely leads to cracks and powdering, which we have got here. Again a known problem, and return to maker for replacement is the only course. They are the ones at fault, not you.

 

Stephen.

[34040]

I first noticed a problem with my D1734 when the fuel tank moulding started making contact with the rail surface. Like others, I then had great difficulty in removing the body. Having done so, I found that the chassis was slightly banana shaped and also looked about three months pregnant. I trimmed the top off the tank moulding and glued it back on but it soon began touching the rails again. Eventually, the body developed a vertical split on one side, close to the inspection door. At that point, I gave up and obtained a replacement chassis.

[Bruce Depot]

Does this problem only really apply to the class 47 chassis, not so far seen anyone mention the cl26/27/33's etc

so are most of the affected chassis from perhaps a earlier casting batch or two?

 

cheers

Keith

[Pixie]

Does this problem only really apply to the class 47 chassis, not so far seen anyone mention the cl26/27/33's etc so are most of the affected chassis from perhaps a earlier casting batch or two?

 

From what Bertiedog's said above I get the impression that time will tell whether other locos/batches are effected. My RES 47 was one of the original batch which I think came out around 2001ish and the first signs of the chassis block expanding became apparent last year, so working on the principle that the problem can take 6-8 years to rear it's ugly head can give rough rule of thumb when they might start to fail. I think this is far from an exact measure as it sounds to me that the problem can be incredibly variable, I guess due to the different levels of contamination.

 

Working with those rough dates though, if any Hymek are affected then the first signs should appear in the next couple of years.

 

Pix

[pitbull1845]

Apologies if I have missed it but is there a special technique of removing the bodies, other than brute force?? I have two 47's both of which appear too tight to remove. I don't have instructions with them so I am guesing its only the 4 clips on the sides that need to be unclipped. I'm hoping that I am not another victim of 47's eating to much chocolate whilst my back is turned!

Many thanks in advance.

 

Scott

[Martin_R]

Hi Scott,

 

Removing the body once the chassis has started to expand is difficult but as I have found you need to just bite the bullet and be brutal! With my RES 47 I cut along the cab door line on all 4 doors with a new sharpe craft knife blade using the door edge and livery transition to mask the cuts. This relieved the pressure just enough to get the body off. You will need to assess each livery variation to see where you can cut but I have found the doors are the best bet as you can touch in or weather to hide the cuts.

 

If the body has already started to spilt on the nose corners use the edge of the yellow warning panel as a cut line but be aware if there is a lot of pressure the body will crack / split into the window apertures and repairs will be much harder to hide.

 

I now store ALL my Heljan loco with bodies off which is a bit of a pain but to date only the my 47's have shown a problem.

 

Hope this helps.

 

Martin

[MickD]

Hi Scott,

 

If you remove the buffer beam there is a aperture for the light unit behind the beam,I use a flat bladed screwdriver to force the body off.

 

MickD.

[EEType4]

My earlier thread Heljan Class 47's, Do I own £2400 of scrap? reported on the class 47 chassis swelling problem.

 

I can now report that after contacting Howes as Heljan's U.K. representative they have supplied six brand new chassis'.

 

Howes service has been nothing short of excellent, the replacement chassis' were with me within a week with no argument. Howes even supplied a couple of Colas bodies to replace the severly damaged ones.

 

You may argue that the bodies are not the same livery but the bottom line is if there are no other bodies available, then they cannot be supplied.

 

We are quick to criticise but I have to say that, personally, I could not have asked for more.

 

Many thanks and well done Howes.