[time-nuts] OT stuffing boards: was GPS interface/prototyping board

[Bob Stewart]

I've given thought to stencils, but without building something to prop my hands on, I'll smear the paste.  So, I place up to 10 or 15 parts at a time and use the hot-air gun.  To each his own, I guess.

Bob

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GFS GPSDO list:
groups.yahoo.com/neo/groups/GFS-GPSDOs/info

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On Thu, 6/23/16, Oz-in-DFW <lists at ozindfw.net> wrote:

 Subject: Re: [time-nuts] OT stuffing boards: was GPS interface/prototyping board
 To: "Discussion of precise time and frequency measurement" <time-nuts at febo.com>
 Date: Thursday, June 23, 2016, 8:16 PM
 
 I'll second this, and
 suggest you consider:
 
  1.
 Pick and place machines use a lot of floor space (even for
 the
     "small" ones are more
 than 1/2 a bench.)
  2. Even the best ones
 require pretty continuous tuning. If you aren't
     using them continuously each new run is a
 new and different
     experience.  Often
 unpleasant for the first few scrapped boards.
  3. You can only place a limited list of parts
 for a run.  If you have
     one more part
 than the machine will accomodate, its a second (or
     third, or fourth pass.)
 
 4. They are all high maintenance in addition to requiring
 tuning. A lot
     of the maintenance is
 based on calendar, not operation time.  Even
     and idle machine requires time if you
 actually want to use it
     eventually.
  5. Most are closed software loops. You work
 around their poor (or un)
     documented
 formats and bugs.
  6. There are really cheap
 small batch assembly houses coming online
  
   that will do under 10 units. See Macrofab, PC:NG, Small
 Batch
     Assembly are fairly quick
 turns.
 
 If all you are doing
 is protos, hand placement, mylar solder stencils
 (see Oshstencils and others) and a hacked
 toaster oven are a good
 solution. The $500
 Chinese reflow ovens seem to require more (re)work
 that a $50 toaster oven.  If you use stencils
 to place the solder, part
 placement is as
 fast (or faster) than through hole parts. I have to use
 a microscope.  I'm shaky enough that  may
 need to built some Waldoes
 soon.  ;-)
 
 I just did six moderately
 complex boards (no fine pitch parts) and that
 was 2-3 too many for me.
 
 Solder stencils make **all** the difference.
 
 Oz, in DFW