This is a small thanks to the site that taught me how to improv things like a linear actuator and power supply for practically nothing and get this project off the ground.
Whilst looking for something to provide a sense of scale in the videos, I decided like any other sane adult would, to collect some dead bugs to play with. I opted not to use this one…
15$ webcam + objective lens = the camera I took most of the early figure pictures with. It got a whopping 5 microns/pixel which is the same as our $3000 macro setup from edmund optics! The downside was it had a horrible depth of field, no focus, no adjustable zoom, tiny resolution, and had to be manually positioned. Every time the table was bumped, you would have to spend 5 minutes finding the same 5mm spot again.
The needles you see in the videos that are fine as human hair can be pulled with a butane lighter with relative ease. Just FYI in case you think I got too fancy, hah.
This is 2 pieces of glass tubing clamped in foam on a ring stand. Just hold the lighter to the center and try not to catch the foam on fire.
This was our first setup, and it was a complete pain in my ass, but it worked. The syringe “pump” was literally a printer stepper motor, a skateboard bearing, a nylon gear, a screw, a nut pressed inside a laser pointer optics housing and some epoxy (thanks hackaday). I drove the stepper with a controller off e-bay (this was before I knew anything about microcontrollers) and to top it off, a jury-rigged ATX power supply that nearly caught fire when I left it on too long.
This was our new setup with (most) the kinks worked out. The pressure you see in the diagram is of the vacuum that held back the metal against hydrostatic pressure. The pulse pressure is 0-80 psi. We are using an off the shelf dispenser designed for solder paste, which is essentially a regulator + aspirator vacuum + millisecond range solenoid valve.