James, we used to use 3 clamshell type printers (one of which did have a two camera vision system, and did all our fine pitch), but had limited success with 20 mil pitch. 25 mil pitch was no problem. I suspect that you'll find people that have had success, albeit with some close attention to details. We also use metal blades.
This is the stuff we had to make sure of:
lift timing: on our machines each front corner lifts on it's own cylinder, and if they come up at different times it skews the bricks....bridges up the kazoo.
squeegee pressure: too little and you obviously don't get a clean pass. Too much, and not only does it tend to stretch the mesh and misregister, but it can also lift the stencil mounting frame depending on how stout it is. In our case it lifted it off the locating pins, so all alignment was lost.
snap off: our machine had 4 independant adjustments, one for each corner, and around here that spells trouble. Too much detail for our operators (we are trying to keep 4 shifts running and rarely have experienced operators on the odd shifts). Try to set yours up with no snap-off, and lock it down so they can't screw with it. Beat up stencils, of which we still have a few, are a little tougher to deal with. Can't replace them all at once, though.
We tape the corners down on the panelized boards, mostly to compensate for warpage, but that would reduce the sticking problems you have.
HTH,
Steve
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