Mount and Reservoir Discussion

[Toasterboy]

Here's a video of the proof of concept injector setup:


It is configured to open the injector for 80ms, and close it for 50ms. That works out to ~7.69 pulses per second (not 20). After the video I did another test and measured it dispensing ~100ml in ~91 seconds. I don't think that it's operating at full capacity yet though.

That works out to ~0.14ml per pulse. (which is about 1/2 micron per pulse z level rise in a ~2'x2' container) Also, the dispense rate would be ~4000ml/hour with this setup, which is about twice as fast as the siphon dripper. Haven't played with varying the open/close durations yet.

I suppose the next steps are to research and select a pressure sensor, and figure out a better tubing solution, so it will take a while before I'll be able to proceed. I'm also pretty sure that the latex tubing isn't sufficient to run at the right pressure.... suspect it's well below 40psi currently and will perform better at higher pressure. I used latex initially because it fails gracefully, and pops like a balloon rather than exploding on overpressure.

It seems pretty clear that this concept can provide some pretty fine control over volume dispensing and timing though.

[3dspider]

You might try some braided vinyl tubing. The stuff I have is rated for 250 psi.

[Toasterboy]

Yeah, that's what I have in mind to try after I get a sensor (and probably an emergency release valve). Will the braided stuff hold around 100psi with barb connectors and zip ties? Rather not have the connections pop off under pressure.

[3dspider]

I usually use barbed fittings and worm gear hose clamps. I'm not sure if zip ties will provide enough pressure.