How to use a vacuum pickup tool?

[alank2]

Do you just center the part over where you want it and release/drop the part into place?  Or do you put it in place and then release the vacuum?

[zapta]

Do you just center the part over where you want it and release/drop the part into place?  Or do you put it in place and then release the vacuum?

I put it in place, sticking the part into the paste.

What tool do you use? I tried a few passive ones but they worked poorly.

[alank2]

I've made one out of a pneumatic dispensing station and a manual pickup tool.  I just turn up the vacuum until I can pickup parts and use the foot pedal to release them with just enough air.  How do you keep from smudging the paste when you press it into the paste?  Maybe my hands just aren't steady enough.

[zapta]

I've made one out of a pneumatic dispensing station and a manual pickup tool.  I just turn up the vacuum until I can pickup parts and use the foot pedal to release them with just enough air.  How do you keep from smudging the paste when you press it into the paste?  Maybe my hands just aren't steady enough.

I keep the pump on until the release. My previous setup had a solenoid valve but I simplify it by controlling the pump directly with the foot pedal.  I don't know if I smudge more or less than you but in general it works well once I reflow it. One thing I made sure is to use the right needle size for the part. I used to needed sizes, a very narrow one for small parts down to 0402 and a wider one for MCUs, USB connectors, etc.

I am pretty happy with my current setup, the most important aspects of it are 1) having an active pump and 2) using a foot pedal for a stable release with no residual vacuum 3) having an ergonomic hand piece (it's a 3D printed handle with the shape of a Metcal handle).

[jwm_]

If you have some scrap laying around that has nice rails the you can make a manual pick b place machine that keeps your parts parallel to the surface.
http://hackaday.com/2014/03/13/manual-pick-and-place/

Various other linkages work too of course, any parallel motion will do.