As you've seen from my recent posts, I acquired a solder paste dispenser on the cheap and have a low-cost hot-air system from eBay. That left only the problem of getting SMT parts on to the paste-covered PCB. Tweezers are a common way to do this, but I always manage to nudge the parts out of position when I let go of the tweezers.
A vacuum pick & place system seemed like the most efficient way to get parts placed on a board. Vacuum is drawn through a blunt large gauge hypodermic needle to pick up a part and the vacuum released when the component is in place. The quick&dirty
method uses a hole in the hand piece to control the vacuum. Seal it with a fingertip to pick up a part, and move the finger to release the vacuum when the part is in position. This part isn't too challenging.
So how do you create a vacuum? The solder paste dispenser has vacuum "suck back" created by running compressed air through a vortex. This method uses a lot of air to create a little vacuum, but since you need compressed air anyway, it works pretty well. I found one of these vacuum generators on eBay for about $12 and was considering building a pick & place system around one of them.
Then I had the thought...nebulizers used for inhaling medications for asthma create a low-pressure, low volume air stream using some kind of pump, and can often be found at thrift stores around here for a few bucks. Hmmmm....there might be some potential there to convert a nebulizer to a vacuum pump. I did a Google search to see if anybody has tried this. I didn't find anything about anybody trying this. What I did find was more interesting! There were a number of listing for nebulizer/vacuum pumps – a diaphram pump is used in nebulizers to create an air flow, but these same pumps can also be used as a vacuum pump!
I was in luck and found a nebulizer at the thrift store today – it had actually been there a while and was still there today. For $6 it was mine. The nebulizer has an outlet fitting for 1/8" or so tubing to the "business end" and a little filter on the suction side – you obviously want the air flowing into somebody's lungs to be clean. The easy way to use this little vacuum pump is to connect the hose to your pickup to the filter inlet. The one I got actually had a little nub to slip a hose over when the filter was removed.
way to do it is to open the case and switch the hoses around. Yes, this is truly a 5 minute project! The former air outlet is now the vacuum connection and the filter becomes the air outlet; this works well as the filter acts as a muffler for the discharge air.
Screw the case back together and you're in business.Nebulizer on Amazon