Rationale

SMD components are small and can be tricky to manipulate. Apparently a small vacuum pump attached to a nozzle is helpful, so I thought I’d build one. This isn’t a new idea: just look on the Internet.1

The basic idea is to make something a bit like a small vacuum cleaner, but one where the nozzle is so narrow that small parts get stuck on the end of it rather than disappearing into it.

Vacuum Pen

You can buy cheap (~£2) manual vacuum pickups on eBay, for example the Aoyue 9392 and clones. They have the requisite nozzle but instead a vacuum pump have a small rubber balloon inside. To pick up a part, squeeze the balloon with a button expelling the air, place the part over the end of the nozzle then release the button. The balloon will expand, sucking the component to the tip.

It’s all a bit hit-and-miss, so I intended to remove the balloon, attach a vacuum pump, and control the whole thing by leaving an air hole in the side. To get vacuum I’d just cover the hole.

In practice though it was hard to get the hole in a comfortable place, so I used the nozzle but discarded both the balloon and barrel. Instead I used a short length of black polyurethane tube (10mm outside diameter, 6.5mm inside) which was a snug, airtight, friction fit on the nozzle.

I melted a ~3mm hole in the side, abusing a soldering iron, and glued the tube to the vacuum pump in the end with hot melt glue.

You could probably make your own nozzle by bending a dispensing needle, and that might be better: 0603 parts are small enough to fit easily in the nozzle from the 939. It’s a 16-gauge3 nozzle, so perhaps you could get a smaller one.

Vacuum Pump

I bought a cheap (~£10) aquarium pump from eBay,the HiDOM HD-603.4 It’s designed to blow air, but by reversing the non-return valves inside it becomes a vacuum pump. This is a well-trodden path.5

Reversing the valves is easy and basically follow these notes from The Danger Zone.6 The key steps are:

  1. Unscrew the base, and take the bellows apart.
  2. Rotate the discs holding the non-return valves through 180°, cutting away a locating pin so they fit.
  3. Put it back together.

The HD-603 boasts a couple of vacuum ports: I plugged one of them with a spare bit of tube filled with hot-melt glue.

Although not silent, the pump is really rather quiet.

Tube

It’s obviously good if the tubing is light and flexible. Clear PVC tube with an inner diameter of 4mm and an outer diameter of 6mm seems to fit the bill, and eBay supplied a metre of it for less than two pounds.

The tube is a good friction fit on the pump, and doesn’t leave too big a gap in the pen barrel.

In conclusion

It’s easy and cheap to build one of these! I spent about £16 and you could probably reduce that a bit by tweaking the pen. A smaller pump might work too: I just don't know.