An airlift pump is a simple device with no moving parts which
elevates water with air pressure - kind of the opposite of a
trompe. All that's
needed is a ready supply of moving air. It lifts water gradually and
reliably.
These ones use standard 1/4" aquarium tubing and fish bubbler pumps.
They're small+streamlined enough to fit through a pop bottle neck. It
can lift water over five feet, using the cheapest air pump petsmart
had. I've had several of these reliably watering plants for months.
Instructions
It prints in two parts, the main body and the hose barbs. Print
in ABS, glue together with ABS pipe cement.
Two barbs fit atop, the inlet and outlet. The straight-through pipe
is the outlet, which belches air and water upwards. The one that stops
halfway is the air inlet. There's a small connection between it and the
straight pipe to let air into the stream.
The fitting on the bottom is the inlet. You should add a length of
tubing to it -- it stops air from bubbling out of the bottom too easily
if the top tube becomes "full". Somewhere between half a foot to a foot
of tubing seems to work for me. Loop it back up to the clip on the
side.
The deeper it sits in the water, the more efficient it will be. You
may need to weigh it down. A topped-up 10L water-cooler jug seems to
have enough depth.
Put a small loop in the tubing a few feet above the water to catch
falling droplets. Droplets which don't quite make it to the outlet
will accumulate in this "trap" until it blocks the air, forcing the
water back up. This caused a large improvement for me.
Never use clothespins to hold tubing in place! It will squeeze the
tubing shut, even if it takes weeks or months to do so, until it stops
working for "mysterious reasons". Use tie straps, twist ties, my
"little pit clip" part - anything that holds it in place without
squishing it.
Digital timers suck. You can't tell when they're broken. A
mechanical timer might break down, but won't throw silent fits the way
digitals do.
Name Last modified Size Description
Parent Directory -
liftpump-5.stl 2014-12-21 11:55 123K Single-output pump
little-pot-clip.jpg 2015-04-06 14:14 30K
liftpump-5.scad 2017-01-10 02:59 12K Single-output pump sourcecode