Do you agree with this assessment of the Hammant and Morgan controllers ?

[kevinlms]

1 hour ago, andyman7 said:

This thread emphasises how unsuited the primitive instincts in the human brain are to assessing risks. There are undoubtedly known risks regarding some of the materials used in these older controllers; that is not to say that when assessed alongside all the other risk factors that life brings us that we should be panicking unduly about them. For example, in the case of ebay, we might argue that they should take more of an interest; but then again I would rather they spent time ridding the site of unsuitable, non-compliant e-bike chargers whcih are statistically going to cause more injuries to life and limb than a Duette is ever likely to.
The main argument made several times over is that all of these old resistance mat controllers are now many decades old, are electrically inefficient and not at all suited to the types of model railway mechanisms that have been used for many years. For me, the modern budget go-to controller of the day has to be the Gaugemaster combi, small, light, efficient - and much easier for kids too than messing around with half wave/full wave/low/high resistance...  

Another one who thinks that anyone saying negative things about asbestos based controllers is PANICKING.

 

Give it a rest why not?

 

The rest of your post about much better controllers, ought to be the gist of the matter, but instead there is too much defending.

[andyman7]

6 hours ago, kevinlms said:

Another one who thinks that anyone saying negative things about asbestos based controllers is PANICKING.

 

Give it a rest why not?

 

The rest of your post about much better controllers, ought to be the gist of the matter, but instead there is too much defending.

Wooah...I made no comment about any individual posts and just reflected that some of the reactions were possibly disproportionate to the actual risks. And I certainly do not 'think' what you assume, nor did I say it. So yes, you 'give it a rest' too.

[kevinlms]

4 hours ago, andyman7 said:

Wooah...I made no comment about any individual posts and just reflected that some of the reactions were possibly disproportionate to the actual risks. And I certainly do not 'think' what you assume, nor did I say it. So yes, you 'give it a rest' too.

If people stopped using emotive words like 'panicking', this issue wouldn't exist.

 

What I commented on!

 

brings us that we should be panicking unduly about them.

[roythebus1]

Oh dear, I've recently acquired 2 brand new Duettes. Brand, not in boxes, cases riveted so I doubt anybody has disturbed the resistance mats. My old Duette which I bought in 1966 still works fine. It is a health hazard because many years ago a corner of the front panel got damaged and I may cut myself on it.

 

Why throw away something that still works nearly 60 years on? How long will all this throwaway transistorised stuff last? About 5 years I reckon. The H&Ms will control all the motors I run including some Kean Portescaps and some of the latest Chinese technology as well as the traditional Triang and Trix motors.

 

Oh, and I've just found a loose H&M resistance mat in a box of bits. Should I panic now or later? :)

 

Edited August 6, 2023 by roythebus1

[AndyID]

1 hour ago, roythebus1 said:

Oh dear, I've recently acquired 2 brand new Duettes. Brand, not in boxes, cases riveted so I doubt anybody has disturbed the resistance mats. My old Duette which I bought in 1966 still works fine. It is a health hazard because many years ago a corner of the front panel got damaged and I may cut myself on it.

 

Why throw away something that still works nearly 60 years on? How long will all this throwaway transistorised stuff last? About 5 years I reckon. The H&Ms will control all the motors I run including some Kean Portescaps and some of the latest Chinese technology as well as the traditional Triang and Trix motors.

 

Oh, and I've just found a loose H&M resistance mat in a box of bits. Should I panic now or later? :)

 

 

I know. Isn't it terrible. Next thing you know they'll be trying to make us drive electric cars 😀

[roythebus1]

41 minutes ago, AndyID said:

 

I know. Isn't it terrible. Next thing you know they'll be trying to make us drive electric cars 😀

I used to drive electric cars in the 1960s, the funfair was a great place in those days. :)

[kevinlms]

12 hours ago, roythebus1 said:

 

Oh, and I've just found a loose H&M resistance mat in a box of bits. Should I panic now or later? :)

 

If you wish to panic, no one is stopping you - I wouldn't. I'd just quietly dispose of the things.

[D J H]

I worry about the staff at the company who offer to re-wind the H&M resistance mats for you

 

https://handem.uk/products/hammant-and-morgan-spares-components-resistance-mat

 

 

[AndyID]

5 hours ago, D J H said:

I worry about the staff at the company who offer to re-wind the H&M resistance mats for you

 

https://handem.uk/products/hammant-and-morgan-spares-components-resistance-mat

 

 

 

I wonder just how legal that is. The UK has some pretty strict laws regarding asbestos.

[PeterStiles]

What I really want is a modern set of 'tronics inside an H&M body.

 

The bit that makes this tricky is that _everyone_ reverses direction with a switch these days rather than having Centre-Off :(

 

But you could give me a set of (say) Gaugemaster internals in a Duette case,  I'd drop good money on that!

[Nigelcliffe]

3 hours ago, PeterStiles said:

What I really want is a modern set of 'tronics inside an H&M body.

 

The bit that makes this tricky is that _everyone_ reverses direction with a switch these days rather than having Centre-Off :(

 

But you could give me a set of (say) Gaugemaster internals in a Duette case,  I'd drop good money on that!

 

Morley Controllers offer a centre-off control in a traditional looking case.   That would appear to meet your requirements.  

 

 

[PeterStiles]

2 minutes ago, Nigelcliffe said:

Morley Controllers

Those look pretty good prices too... now to buy one and transplant into a Duette case :)

[lesmond]

On 22/09/2023 at 19:23, AndyID said:

 

I wonder just how legal that is. The UK has some pretty strict laws regarding asbestos.

 

They have some useful control knobs and some other bits for not too much.

 

I notice that they are now repairing resistance mats on a exchange basis.

 

Les

Edited September 27, 2023 by lesmond

[Dave B]

I have to correct something I posted a while ago. I said that the Powermaster and the Safety Minor don't have any evidence of asbestos because they use a variable transformer. 

My Powermaster has the slider control variable resistor for full-wave to half-wave which is wound on what is most likely asbestos. My Safetyminor does not have any asbestos at all though. I would assume that the Powermaster versions with a switch, rather than the slider resistance,  would not have this asbestos.

 

I have removed the slider control, shorted out the wires to it and blanked off the slot.

 

Also to say, that when I replaced the selenium rectifiers with a semiconductor bridge, I found that on no load the o/p rose to 80V or so when measured by my high impedance DVM. Not dangerous because this would be due to a small charge build up which is easily discharged with a load of any sort. I assume this build up of charge was kept low by the leaky selenium rectifiers. Modern semiconductors don't have such a high reverse leakage current, and thus allow the build up of charge. The solution was simply to put a 10K or thereabouts resistor across the + and - pins of the bridge rectifier. 

[simes]

Interesting advice, thank you Dave B.  I have the newer Powermaster (low line case, half-wave switch instead of variwave slider) and can confirm it does not contain anything that looks like asbestos.  Like you, I have removed asbestos-like material and selenium rectifiers from old H&M controllers.  Peter Stiles, up-thread, mentioned that it would be good to have modern electronics inside a H&M case.  That is what I have done, updating a Clipper, an Executive and a Commander with Roger Amos' circuit designs.  (The Powermaster I left as it was.  I keep it because the 2.5 amp supply is useful for old O-gauge motors.)

 

I would be pleased if someone with the necessary facilities could test the asbestos-like material on H&M resistance mats to confirm whether it is or isn't asbestos, because trade terms were looser in those days and sometimes material which was not asbestos was described as such because 'asbestos' was more meaningful - before the danger was known.  If it really is asbestos then I too am surprised that there is a business in re-winding the mats.

[kevinlms]

42 minutes ago, simes said:

 

 

I would be pleased if someone with the necessary facilities could test the asbestos-like material on H&M resistance mats to confirm whether it is or isn't asbestos, because trade terms were looser in those days and sometimes material which was not asbestos was described as such because 'asbestos' was more meaningful - before the danger was known.  If it really is asbestos then I too am surprised that there is a business in re-winding the mats.

We are going round in circles here.

 

We have two schools of thought in that some believe that if it MIGHT be asbestos, then they are simply not worth the risk and besides, they aren't a great controller anyway.

 

Others believe that it is something to be laughed at, because they have used them for years and aren't dead yet.

 

Testing would give a definitive answer, but some have said that they LOOK like asbestos.

However a proper certified test, from a competent organisation, would probably cost far more than they are worth.

 

It's actually true to say that the dangers of asbestos, have been known for a century or more, but it was convenient for business, to pretend that such health risks simply didn't exist. Same argument used by tobacco companies and some well known drugs.

[simes]

Hi Kevin, I don't disagree with you. In fact I'm close to agreeing fully.  I was thinking we might be able to cease going round in circles if someone has a way to test a sample. 

Edited January 11 by simes
Typo - autocorrect had written 'treat' for 'test'.

[kevinlms]

1 hour ago, simes said:

Hi Kevin, I don't disagree with you. In fact I'm close to agreeing fully.  I was thinking we might be able to cease going round in circles if someone has a way to treat a sample. 

I believe that a sample suspect item can be sent to a suitable test centre. However

1/ I don't have any of this type of item to send. I'm certainly not going to acquire one just for the purpose of getting it tested!

2/ I'm in Australia, so far more likely that someone in the UK, could arrange a test, that would be acceptable to a UK market.

 

My comment about 'going round in circles' is related to the fact that many thousands of these were made, but no one apparently has ever tested one to the required standard (a qualified lab - under the microscope I believe) and publicly released the result.

[Dave 46]

Samples for testing should ideally be properly (double) bagged for submission to an approved centre.  I submitted some Artex ceiling samples for testing about ten years ago, and my fading memory remembers the cost as about twenty five quid per sample then, but I may be misremembering.

Dave

 

[WIMorrison]

If you are really concerned about whether it has asbestos or not then buy a kit and test the suspected item.

 

There are lots available online, here are a few;

 

Asbestos testing kit

 

Cheapest appears to be around £15

Edited January 8 by WIMorrison

[rodent279]

I just ditched my H&M Powermaster at the tip in the small electrical section. It worked, but had been bashed and dented, although structurally intact, and to be honest, had done its job after over 60 years. I just cant get sentimental about something that is an inanimate piece of kit that does not move or make a noise, apart from a slight hum. I have got more modern, more capable equivalents, including a self-built unit. I did think about salvaging the case and putting modern innards inside, but what for? A lot of effort just to pretend it's still 1965 and I've just received it for Xmas.

[kevinlms]

5 hours ago, WIMorrison said:

If you are really concerned about whether it has asbestos or not then buy a kit and test the suspected item.

 

There are lots available online, here are a few;

 

Asbestos testing kit

 

Cheapest appears to be around £15

Except 'kits' like that are just a means of packaging, to send away. My searches brought up responses like this.

 

 

Looking for a DIY asbestos test kit?

If you’ve heard of “asbestos testing kits” being sold at hardware stores, you may have got the impression that asbestos testing is something you can do yourself.

This is not the case. The only way to test for asbestos is in a scientific laboratory, using specialised techniques like Polarised Light Microscopy (PLM) and Dispersion Staining (DS).

[kevinlms]

6 hours ago, Dave 46 said:

Samples for testing should ideally be properly (double) bagged for submission to an approved centre.  I submitted some Artex ceiling samples for testing about ten years ago, and my fading memory remembers the cost as about twenty five quid per sample then, but I may be misremembering.

Dave

 

With what result?

[2750Papyrus]

I've just had to use my last "new" FS2 passing contact switch, still boxed and containing the maker's guarantee!

[Reorte]

19 hours ago, WIMorrison said:

If you are really concerned about whether it has asbestos or not then buy a kit and test the suspected item.

 

There are lots available online, here are a few;

 

Asbestos testing kit

 

Cheapest appears to be around £15

Do you have to send off the entire thing (which may be rather too bulky), or dismantle the bit that might contain asbestos (which I would very much not want to do, even if I was quite happy to carry on using it)?