Hang about. I'm not in a competition here to provide the perfect answer, If I could
do that based on a couple of postings I would be beyond even the Werner class.
Suggestions made are to help provide information which will help find a solution. So
you can either try and describe the internal shape of a dispense needle using words
or say take a look at those supplied by.. The intention is to increase the knowledge
base at the other end. I know the standard EFD syringes are a bit wibbly woobbly for
precision automated high speed dispensing, but they have knowledge in this area and
probably can add 2cents and a couple of other contacts and so on.
If you want a pumpkin wine recipe you can have it, but I didn't want to clutter the
whole of technet with it.
Mike Fenner
BSP, OX15 4JQ, England
T: +44 1295 722 992
M: +44 789 999 7715
F: +44 1295 720 937
-----Original Message-----
From: Paul Klasek <[log in to unmask]>
To: [log in to unmask] <[log in to unmask]>
Date: 10 September 1999 01:10
Subject: Re: [TN] Clogging dispensers soon...
>OK , LETS KEEP IT SIMPLE ; TO SAVE JASON FROM VERTIGO
>READ INSERTS BELOW
>
>-----Original Message-----
>From: Ingemar Hernefjord (EMW)
>[mailto:[log in to unmask]]
>Sent: Thursday, 9 September 1999 22:42
>To: [log in to unmask]
>Subject: Re: [TN] Clogging dispensers soon...
>
>
>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,
>
>HHMMM, MUST i INGE ?
>SUPPOSE ; DID YOU NOTICED BOTH IN AND AE STOPPED THEIR PUBLISHED WORKS ON
>BEGINNING OF RESEARCH OF MAGNETIC FIELDS ?
>COULD UNDERSTAND WHY . NOT SO SURE BOUT EMPRESS MAGGIE
>----------------------------------------------------------------------------
>--
>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.
>
>WE ALL AGREE ON THIS ONE (BUT IT'S NOT PLASTIC MOUNTED EFD)
>----------------------------------------------------------------------------
>--
>
>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.
>
>EFD WILL NOT HELP YOU IN THIS PRECISION END (YOU NEED OUTER CHAMFER = SHARP
>EXIT EDGE FOR FAST RELEASE) ;
>NEVER SEEN THIS PRECISE NEEDLES FROM THEM ; AND YOU NEED THE SIDE FOOT STILL
>----------------------------------------------------------------------------
>---
>
>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!
>
>TOO SOFT , BEEN THERE, SOME 20MM LONG ; NO SIDE FOOT ; THOSE ARE GOOD FOR
>LETTERING CAKES !!!
>HONEY OR ELSE ; FORGET IT
>----------------------------------------------------------------------------
>------
>
>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.
>
>WELL , INGE , DID YOU NOTICE HOW GOOD WAS THE INTERNAL SURFACE OF THE
>CLAMPED PAD ITSELF ?
>SEEN NANOMETERS HOLES PERFECTLY SMOOTH ; CAN'T SEE THE ISSUE
>----------------------------------------------------------------------------
>-
>
>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.
>
>AGREE WITH THIS ONE ; IF YOU WANT IT RIGHT, DO IT YOURSELF
>(MUST BE THE ENGLISH WAY)
>----------------------------------------------------------------------------
>-
>
>F:
>waiting for pumkin wine recipe, you just opened a new file, I need something
>to pour into it......
>
>MIKE ; ME SWEATING HERE HCL JUST TO AMUSE JASON (FRIENDLY IDEAS, STIFF
>SHIRTS?)AND YOU KEEP PRIVATE PING PONG WITH INGE ? PAUL
>
>CU
>
>Ingemar Hernefjord
>
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