control vacuum pressure

Hi all,

I have a project where I'm using a 6 servo arm to pick up game cards. However, the 12v vacuum pump that I'm using is very strong - and picks up 3-5 cards at a time (instead of the desired 1 card). Are there any tips (chips, code, hacks) for the best way to control the pressure that the 12v pump creates?

Any suggestions would be greatly appreciated! Thanks all.

Are there any tips (chips, code, hacks) for the best way to control the pressure that the 12v pump creates?

If the Arduino has no control over the pump, why would you assume that some code would help?

A manually variable valve that introduces leakage. Or some holes to bleed off vacuum.

Can you do something about the design to avoid picking up multiple cards? What exactly is happening? How does vacuum pass through a card such that multiple cards get picked up? That seems impossible unless they are porous.

If the cards are very flat and smooth, then air can't get between them quickly, and the resulting partial vacuum between cards will allow more than one to be picked up at a time (regardless of the mechanism doing the picking).

So the cards are essentially sticking to each other. Maybe some talc would help? Or other modification to the cards themselves.

jremington:
If the cards are very flat and smooth, then air can't get between them quickly, and the resulting partial vacuum between cards will allow more than one to be picked up at a time (regardless of the mechanism doing the picking).

Replace the cards with ones that are not porous (plastic coated?), then air can't leak through?

Or it might just be that the cards need to be made slightly roughened to allow faster airflow
between two cards so gravity can separate them more rapidly.