german spreaker?

"high-grade steel oaths platinum"

Not sure where the oaths come from, perhaps when you burn yourself??

Peter

-- Peter A Forbes Prepair Ltd, Luton, UK snipped-for-privacy@easynet.co.uk

My German is limited to the chorus of Beethoven's 9th Symphony :)) but 'oaths' in this context could be 'guaranteed'.

JG

Edelstahl is stainless steel. Seide is silk (but that makes no sense here, it can also be interpreted as silk thread) and Platin would be platinum, but I guess it's just a name they use. Yes, if you ask what silk has to do with a wire, it doesn't. Read it as flexible, silky, smooth.

But for a foam cutter, why not use constantan?

Couldn't resist to correct the typo in the subject. :-)

Nick

I believe Silk was used as insulation on wires before they had anything better, we're going back a LONG time though 8-)

Greg

anything

Oi not that long! Many is the coil I've wound with DSC (Double Silk Covered) wire It was always the posh alternative to DCC (Double Cotton Covered).

AWEM

But then I guess they would have called it silk isolated. If that wire is as flexible as the highly flexible wires used for DVMs etc., "silk" would make sense.

Nick

Sorry, no offence intended 8-)

Greg

Nichrome wire seems to be the favoured thing for this, readily available from many model aircraft suppliers as we use it to cut foam wings.

Greg

Bloody high grade?

Regards, Tony

Guten Abend der Herren!!

Ich spreche fliessend deutsch und edelstahlseide Platin bedeutet:

Stainless platinum wire.

edelstahl - simply means stainless seide - means in this case wire (commonly used word in German t describe thin wire, fishing line, dental flos and of cause silk.

platin - do I need to explain that one?

Some German words tend to be made up of 2,3 even 4 words!!

all the best

Edwar

-- Kingtwitche

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this thread:

Avoid nichrome at all costs! Too brittle. Not strong enough. Kinks too easily. Breaks. Sags. Hard to make a decent contact, hard to handle, and hard to use. Yuck.

Nothing is more likely to put the beginner off than the use of nichrome wire, and the pro's don't use it either. It has no useful place in the foam-cutting world.

I think someone thought that nichrome would be good, but never actually tried using it. Its anti-oxidation properties are not necessary, especially for hand work in contact mode where the temperature is low except when cleaning the wire, and it it HORRIBLE to work with.

Someone suggested constantan, I haven't tried that.

For hand work I'd normally recommend a beginner to use 7-strand stainless steel fishing leader, and for the experienced 0.25 or 0.2 mm single-strand stainless wire - but this stuff is 0.35 mm 19-stranded and is particularly good, doesn't kink, doesn't unravel much, is lovely to handle and easy to use, doesn't seem to soak up melted foam, seems very long lasting and leaves no visible strand marks in contact mode.

[The wire either touches the foam and melts it, or it melts it by infra-red radiation without contact. Contact mode is the only mode suitable for hand work. For cnc work IR mode can be better, it can also leave a thicker and more reliable skin of melted foam, but you have to take wire speed into account.]

I wondered if it was platinum-coated/plated stainless wire. It came from a jewellery bits-n'-bobs company, originally intended for stringing expensive beads.

I googled a bit for that product. It is not platin coated. It is just platin colored. Also available in "gold". Cheap stuff. 4m, diam 0.2 cost below 3.- EUR. I found that in quite a few artscraft stores, but no translation.

HTH, Nick

Well obviously your mileage has varied 8-), but a great number of people use Nichrome with no bother at all and it's sold by most model suppliers for this purpose. One point to mention is that the Nichrome used by the aviation industry as locking wire is the wrong stuff as it is fully annealed, maybe people are mistakenly selling this for hot wire cutting and thus giving it a bad name?.

As to the professionals, well they have the benefit of sophisticated electronic controls that continuously adjust the current to maintain the wire temperature, something that few amateurs do.

Greg

They use it and have a great deal of bother, as the wire breaks because it is too brittle. It is also hard to connect properly, and this causes breaks too. And it stretches and sags, and it doesn't last long.

It shouldn't be, as it is totally unsuitable, especially for the amateur. Stainless or inconel are far better suited for the purpose.

Never come across it. I would imagine that annealed wire would be better for anyone not in the expert class anyway, as it would be less brittle and brittleness is the main problem with nichrome.

The expert might want to use work strengthened wire for the greater tensile strength, but it's easier just to use stainless or inconel wire instead. Oxidation is not a problem with either, the high temp anti-oxiation properties of nichrome are completely unnecessary.

And nichrome is horrible to use, and it breaks.

I don't know how much cutting you have done, but have you ever tried using stainless? Most cutters who have would say that it gives better results than nichrome, and certainly it is far easier to use.

Cutters argue a lot about which is the best wire of all, stainless or inconel, and whether the extra expense of using inconel is justified, but nichrome doesn't usually get a look in.

Most would agree 7-stranded stainless fishing leader is the best for the beginner though.

As I said your experience has obviously been different from mine and that of others I know, but I do think you're exaggerating with such sweeping statements.

Greg

Hmm...I've got several (many) hundreds of metres of what for some years I have assumed is Nichrome - shiny, never oxidises, about

0.67mm diameter and about 2.5 - 3 Ohms/m at 20deg. I've used it for crude cutting of 8ft x 4ft sheets of polystyrene with no problems. It flexes easily, doesn't break when flexed and has also survived well as a rebuild heating element for a small oven at 1000deg C.

Anyone who wants some to play with is welcome as long as they tell me what it is if they find out! A donation of your choice to REMAP

if it is useful would also be appreciated.

You echo my experiences and those of others I know who use it for foam cutting, except that mine is slightly thinner, about 8-9 ohms/meter, and the reel is labelled Nichrome and sold as such so I don't think there is any likelihood of it being anything else.

Greg

Unfortunately my (large, difficult to pick up) reel/drum isn't labelled at all. However it was too good to miss at an auction when going for 50p I think.

0.67 mm Nichrome A or C would be about 3.4 ohms/metre at 20C - 304 stainless would be about 2.4 ohms/metre.

Nichrome does work - but it is usually a problem to use, stainless is much easier and less prone to breakage. A 0.67 mm dia wire is quite a bit thicker than most foam cutters would use though, so breakage might not be a problem for that reason.

That doesn't sound like nichrome.

Perhaps it's not stainless then, though iirc 310 (?? - one of the 300-series anyway, the one also used for high temp thermocouple sheaths) will work well for long times at 1,000+ C.

Yes please, Thanks, and for sure I'll let you know what I find. Might be a while though as I am off to work for a bit soon, then into hospital (at last!!).

What sort of donation would be good? Money I do not have a great lot of.

I used to work/play with some of the thalidomide kids in PMR Edinburgh when they were about 6 to 8, and they had some wonderful pneumatic stuff then, but it doesn't work so well when they grow older, get too big :(.

One little girl had a pair of CO2-cylinder-powered legs, and had spaces for four cylinders, which she would ask people to replace for her. The nurses would warn people not to fill up all four spaces, as she would run around for ages and they couldn't catch her!

Hmmm. I'll think of something.