Procrastinatus

Why talk about it now?

Hack – DIY Cheap Vacuum Pump/Vacuum Tweezers

Posted by aonomus on May 12, 2008

I started this hack after salvaging a gigantic ghetto token ring hub using a heat gun, and having dozens (read near a hundred) SMD IC’s which needed to be sorted, and my tweezers were simply not up to it. Knowing that real vacuum tweezers can cost more than the budget of hobbyists, I thought of a nifty way to make vacuum tweezers on the cheap.

Starting from an aquarium air pump, I assumed that there were bellows and membrane valves which could probably be reworked. Opening the (crusty) pump I had in the basement, I find just that. You can see that there is a single coil and a permanent magnet which causes the arm to move back and forth thanks to AC, and the rubber bellows which are our next victim.

Open the bellows up and observe where the valves are, in particular where the air is supposed to flow on each stroke of the bellows, and then reverse the valves. The original pump had small latex rubber flaps wedged in by larger pieces of rubber, and you can see in the photos below I have already temporarily wedged the membranes into reverse positions. The basis of this is reversing an air compressor so that instead of pushing air through the output, it sucks air out when trying to refill the chamber, basically just flipping the pump around in reverse.

Once you have the valves switched around, reassemble the pump and check how much vacuum you can pull, it won’t be much, less pressure than when trying to pull tape off your hand, but enough to lift some very small, very light SMD components. In order to turn a simple vacuum pump into more of a refined tool, I added a tip from an bike pump to the end of the tubing to form a better seal, and a check valve just as added protection in case the membranes did not function too well and let air travel back into the tubing.

This is a pretty simple hack, some improvements I plan on making are:

  • A more permanent way of holding the membrane valves in place
  • Hand-held airbrush like tool to allow for vacuum to build up, and to add a grab/release valve
  • Improved tip which more closely mimics vacuum tweezers to allow for larger chips, perhaps even heat resistant for actual hot-air-rework or hot-air-desoldering.
  • An air filter to prevent small particles or even bits of solder from entering the pump
  • A more soundproof way of holding the air pump steady, it tends to vibrate loudly, even to the point where it will vibrate off the table it is sitting on.
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