Mike, your help is of same high standard as is Aussilek's (yes, Aussilek, you must accept even english are bright, rembember the Piltdow man, Nelson, Newton,Thatcher and Kermit),
now, Mike,
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A:
It sounds from this and previous postings "that in view of your demanding application
it might be better to use a higher specification needle than the standard type
normally supplied". Or whatever your present supplier is saying.
Such a higher specification might be one in which the moulding around the steel tube
does not have sudden cross sectional changes and no internal reverse re-entrant
shapings.
RE: exactly what we will do, we have cross sectioned and seen what you mean. We have a reputation for making tough specs, we will use that from now on.
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B:
You can get these OK from people like EFD. So far as tube length is concerned these
suppliers also make a shorter length, but still long to allow manual access. No
reason why you should not cut them down, provided you can get a good finish. I
suggest a length no greater than 5-6mm.
RE: please explain who EFD is, we will call immmediately.
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C:
It just might be worth investigating the type also supplied for solder paste
dispensing. These are made entirely of polysomethingene. And are a conical cross
section from fitting to dispense end. The problem is they can be flexible and may not
give precision placement accuracy.
RE: good idea! May be a little bit cheaper also, ours cost 200GBP each!
----------------------------------------------------------------------------------
D:
Reverting to your question on internal finish of needle:
From what little I know about laser machining I suspect you would have great
difficulty making a smooth hole of this size and length. Irrespective of that,
whatever method you use to correct the internal finish it would be especially
difficult to build a tool to hold the needle and get the alignment you require.
So as an alternative you could make your own theoretically perfect ones. These would
consist of a hemisphere internal shape with a projecting tube just long enough to
clear the external body of the hemisphere from the substrate surface to prevent
smearing.This would be much easier to make.
RE: Also good idea, like putting a fine needle into a wider, and the finer only a millimeter ore two long. THEN you may be able to use laser.
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E:
I now recall visiting a company once that is using these, or at least was about 18
months ago, in high speed component manufacture, I believe they made them themselves
but if you become convinced this is an answer then I will try to remember where and
who they are and see what I can find out.
RE: please, look once more in your drawer.
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F:
waiting for pumkin wine recipe, you just opened a new file, I need something to pour into it......
CU
Ingemar Hernefjord
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