We had better luck with Bernoulli cups to move paper from a ream to our platen where it gets printed on. We grab the paper by the short edge and drag it over, easier than trying to lift it off vertically. The platen has its own vacuum so the paper gets sucked down in place. Works pretty well but we still need to recover from errors, especially when changing paper types.
In all my research I never came across (or didn't understand) Bernoulli cups. This looks like it might have solved our original problem with suction cups: they would pick up huge amounts of paper. We're talking like 5-15 sheets. We tried turning down the suction, etc, but there was no way it was ever going to be precise enough. Thank you for sharing this, I just learned something new and super cool.
What's your application? You say your platen has a vacuum, did that affect writing quality (assuming you're writing)?
This is for an internally developed printhead test tool (at hp) so money is not as much of an issue. We place the paper on a very flat vacuum platen and then print various test patterns with our (industrial) printheads. So the printing part is easier than what you're doing, printing more or less the same way you'd do in a flat-bed plotter.
We did play around with various ways of picking paper and it's generally a tricky problem, even now we have to adjust the flow for different paper weights. We also came up with a simple way of dropping off extra sheets by forcing a little bow to the paper and shaking a few times for the extras to fall off.
