Ordered one of these solder paste dispensers from GoodLuckBuy: http://www.goodluckbuy.com/solder-paste-glue-dropper-liquid-auto-dispenser-controller-klt-982a.html
Mainly chose this one because it runs on 24V internally rather than 110/220V and many of the other models apparently use mains voltage through the foot switch!
I paid extra for DHL shipping (about $20) and it arrived within a week. The model I received is a bit different from the one pictured. Its a Speed SP982 rather than a KLT-982A though there isn't much difference (they're all clones of each other anyway
) It has a screw in connector for the foot switch as well as a mono audio jack for an external trigger. Unfortunately, the finger button trigger in the pictures was not included (no big deal). I did a quick check internally to see what its like. Typical chinese construction but at least it has the ground lead of the IEC socket connected to the chassis. The foot switch and external trigger jack are wired in parallel. A potentiometer on the front sets the dispense duty cycle (0 to 100%) while a set of dip switches on the back set the overall time (1s, 10s, 20s, 30s). Each press of the foot switch triggers one dispense cycle. Holding the foot switch down does NOT continuously dispense shots. Another switch on the front puts in in manual mode where you modulate the dispensing with the foot switch directly.
I'm running it off a small 21L 2.5HP compressor regulated to ~80psi. Regulator on the dispense unit is set to 50psi. I fill it up outside since its quite noisy. A full tank lasts for ages inside
Solder paste is just "Mechanics" brand paste from DealExtreme which comes in a little pot. First test run turned out great. Video was filmed on my iPhone 3GS in pretty poor lighting so excuse the crappy quality
I'll get some internal shots later.
The internal control board looks like its just a 555 timer with some analog components. Looks pretty basic and it doesn't have to do much. I'm considering replacing it with my own board using a microcontroller, so I can also do continuous shot intervals.
Quick YouTube vid:
Completed board with a hotair tool