Hi Steve,

Whenever we buy new equipment we'll do extensive acceptance testing so that we don't spend money on something that doesn't work as good as promised. For a stencil printer this includes printing a batch of our own testboard, which is big HASL'ed board with 0.4 mm pitch QFP's 256 in the corners. Printing those tiny DEK demo-boards tells me nothing.... 
Now for me there would be one big difference between buying new and used equipment: if it's new equipment we'd do acceptance testing after installation in our production, but with a used printer I would only feel confident after passing these tetst on the site where you want to buy the machine from. After installation I'd repeat most of the tests.

Kind regards,

Daan Terstegge
SMT Centre
Thales Communications
Unclassified mail
Personal Website: http://www.smtinfo.net



>>> Chris Murphy <[log in to unmask]> 09/11 6:38 am >>>
Steve,

I'm no expert on the 288 - I saw some being refurbished by Dek in
Singapore recently and like you was scared off by the huge footprint and
complexity of the machine compared to the Dek 265's.

Obviously the trade off on the cheaper purchase price of second hand
gear is the risk that you take if you dont know how the machine has been
treated during it's lifetime.  The simple answer is that if it your ass
on the line then take the least risky option - purchase new, or get the
guys at Dek to give you a price on a thorough overhaul.  If your
employer wants you to save money by taking a risk, then they should be
prepared to support you if things turn bad.

Have the machine suppliers got evidence of a comprehensive maintenance
program carried out on the machine?  The machine recognised the screen
and PCB fiducials which is good - did it have QC Calc installed which
showed the repeatability of the machine using the same board and
screen.  Did you have to put offsets in the file or did the alignment
work with no offsets?  Also how accurately can you assees the alignment
accuracy by looking through the screen apertures through to the PCB.

It's a shame that there were no squeegees present - you could have
checked out the pressure transducers - we had problems with the
stability of ours on our Dek 265 earlier this year. Even if you could
have done a wet print there are loads of other things that you will not
be able to spot without stripping the machine down, all the more so with
a complex machine like the Dek 288.  And of course you know how
expensive machine parts are to get.

But on the other hand.......if you felt that the machine was in good
condition, you can trust the previous owners, etc. etc.  And Dek's are
good machines.  But you sound like you already know the answer.

Regards,

Chris Murphy



"Stephen R. Gregory" wrote:

> Hi All!
>
> Hate to keep beating a "dead-horse" so to speak, but I just returned
> recently
> from looking at a used DEK-288 that we've been thinking about buying
> to
> replace the 265 MK-1 that we have here, just trying to upgrade things
> a
> bit...
>
> I've been thinking about things for a bit...I think this may be a good
> thread
> because there probably more than just a few of us out there that
> consider
> buying used...er,  "Previously Owned" (that's the polically-correct
> term)
> equipment.
>
> Maybe I'm being a little paranoid because it's going to be on my
> recommendation whether or not we buy this printer (there's a few more
> conditions that the finance guys would like to have, but they always
> do) but
> bottomline, I'm supposed to say whether or not the machine is a good
> investment for us or not. It doesn't help a whole lot that I don't
> have much
> experience in 288's...265's yes, 288's no. If I recommend that we buy
> this
> machine and do, then the machine doesn't perform at least as well as
> our 265
> did, it's my job...and my ass.
>
> I've bought used equipment in the past, and have had pretty good
> success...er, luck, when buying it. (That's not fair, there's a lot of
> good
> used equipment out there, and good vendors as well...).
>
> My intentions in evaluating the printer, was to look at the overall
> condition
> (you can tell a lot from first impressions) have a stencil and PCB
> (from one
> of the more challenging assemblies that we build here), a jar of
> solder
> paste, then program and run the printer, and finally check the quality
> of the
> print...
>
> I thought that would be a pretty good, simple, evaluation of the
> machine,
> along with understanding that the machine is used, and not
> refurbished. I
> thought that would be a straight-forward way to see if the machine was
>
> basically sound...
>
> Maybe some belt replacements for the ones that were pretty worn, some
> calibrations, a good, thorough, spring cleaning would be in order,
> etc...
> would not be out of the ordinary (in my opinion) when buying a piece
> of used
> (not refurbished) equipment.
>
> However, when I arrived after flying out to see the printer, I learned
> that
> only then, that there were no squeegees available. I was however able
> to have
> the programming demonstrated for the stencil and PCB that I brought
> with me,
> and watch the machine load the board and find all the fiducials (both
> PCB and
> stencil), and watch the machine go through the print stroke with the
> pressure
> set at zero (no squeegees) so it wouldn't alarm.
>
> Maybe I'm asking stupid questions, but should I consider that a
> reasonable
> demo? I expected to be able to print a board, and then look at the
> print and
> then evaluate it.
>
> But it didn't happen. I'm I being overly cautious? If the printer can
> find
> all the fiducials and then go through the stroke with the pressure set
> at
> zero and not alarm, could one assume that things are basically sound?
> It did
> appear that things were aligned pretty good from peering at the
> stencil to
> board registration standing outside the printer when the PCB was up
> against
> the stencil...I would have preferred to see where the solder paste
> ended-up.
>
> I guess why I am so worried, is because of my perceived complexity of
> the 288
> print head...it can print in any direction (almost) that you want.
> "Vector-print" as DEK called it, has been discontinued, and is one of
> the
> basic differences between the "Infinity" and the 288...aside from the
> price
> and footprint.
>
> I don't know squat about the print-head, and don't know what could be
> not
> seen about the machine's condition by not doing an actual print. What
> could I
> be missing by not actually observing a "Wet Print"? It has been
> suggested
> that I'm being overly cautious, and that my concerns aren't really
> warranted...as long as the machine found the board and stencil, and
> went
> through it's print-stroke with no alarms when the pressure was set at
> zero,
> things are cool...
>
> I welcome any and all responses. Sorry for what may seem silly
> questions.
>
> I'm not expecting anybody to give me a recommendation of whether or
> not I
> should buy this printer, that's all going to be my decision
> (recommendation)
> ultimately. I'm just trying to learn if my concerns are valid or
> not...
>
> -Steve Gregory-

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