On 26/07/2011 20:35, Isaac Marino Bavaresco wrote:
>>> Perhaps one can avoid the knot by using a thinner thread and wrapping i=
t
>>> >>  twice around the bottle, twisting it around itself all the way.
>>> >>
>> >  Sounds like a good method - another idea is maybe (if doing this
>> >  regularly) to avoid the knot/alcohol/flame you could replace the thre=
ad
>> >  with something like nichrome wire and current source? Also you might
>> >  have more control over the heat this way.
> Again a problem may happen at the point where the knot would be, you
> must leave a gap so the wire doesn't get shorted and it may cause a
> defect also.

Good point, I was thinking you could either have some very thin=20
insulating material that slides the wire past itself at the point, but=20
then as you say you probably will have the same sort of problem.
Or, if you accept the nichrome will be wrapped round n number of times=20
and shorted, and calculate resistance accordingly, then apply=20
connections for current flow at opposite sides you would have a=20
situation similar to that you described with the thinner thread wrapping.



--=20
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