I'm going through the same thing right now...  I (my staff actually) 
currently hand-inserts through hole, and then I have a wave solder 
machine.    We have no meaningful SMD technologies.

The following is my observation and experience....

Wouter van Ooijen wrote:
> One of my PCB suppliers offers to make a stencil for an affordable 
> price. alternatively, the machine can be equipped with a solder paste 
> dispenser.
That sounds like what I keep being told.   Madell makes several "manual" 
stencil printers for under $500 which can be used with any of the cheap 
stencils.   I am also looking at several of the automatic paste 
dispenser options.    I'm still flopping between the stencil and 
dispenser options...

On the stencil side, I've played with the polou mylar stencils and they 
seem to work fairly well just with the "tape them to the board" 
method.   My board manufacturer also does the stainless ones for not a 
lot. For longer runs, I would want the stainless units on a manual printer.

On the other hand, the dispensed paste seems really attractive, 
especially since it is a lot easier to deal with on low runs - that is, 
I can do one or two panels of each type of board and I don't have to 
worry about cleanup of each stencil.  
> Simple hot-air / IR ovens seem to be affordable, and we have some 
> experience with one at my school.
>   
I have a Madell tabletop conveyored one, which seems adequate (note I 
didn't say great, but simply adequate), for tin/lead work.   
Easy-Profile 256 paste seems to work well in this oven.  RoHS seems a 
bit more of a challenge.
> dunno, I do not wash my current PCBs...
>   
Neither do I.   Don't think it's necessary anymore if you use the right 
paste (or in my case, soldering flux).
> sure? that seems 'a bit' on the high side..
>   
I agree.. 50k is quite a bit high.   If I had 50K, I'd be looking at 
some of the middle-end manncorp lines at 
https://www.manncorp.com/turnkey/index.php?auto=done - although I'd 
probably swap the stencil printer for a paste dispenser.

-forrest
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