This Project started more than a year ago with inspiration from Casual Profanity, Casual Profanity picked up on the Make Magazine Blog. I was very impressed with what I saw, and is this tied in with my general fascination with fluids, I thought it worthwhile to investigate the concept myself.
Information on how to achieve the effect was fairly scant, so I ended up heading off in my own direction, finding there were a number of key elements.
Pump- The pump is an industrial flojet part- similar to that used in caravan and boat freshwater systems, found as a new old stock part on ebay. It needs to be a diaphragm pump to cope with pumping both air and water and be self priming.
Valve- The valve is an industrial part, found in the scrapyard, which although it was intended for air, seems to work fine with water once the exhaust breather is ducted back to the tank. It is a unit that switches between two inputs to one output.
Tank- A simple part- a used screenwash container. The fluid used being water with food colour in it.
Tube- My hope was to make something big, which was going to require a lot of tubing. I got lucky eventually, obtaining 90m of PVC tubing through ebay for less than £10.
Electronics- This unit was put together by my friend Paul.
The Complete System
The system works by using the pump to draw the fluid through the tube before returning it to the reservoir. The pump speed can be varied by a PWM control on the electronics board. Initial trials were with the pump at the input to the tube, but control was difficult, I believe because the large volume of the diaphragm chamber was limiting the resolution. The valve switches between the fluid pickup from the reservoir and drawing air into the tubing, and is also switched by the control board.
Progress to a working application was slow due to moving house, other projects and sourcing appropriate parts, but a mostly completed and functional unit was ready for this year’s UK Maker Faire. The response we got was great, much better than expected with many people standing and watching for quite long lengths of time, and with plenty of engagement for new directions and ideas. Interestingly for me as an Engineer- it’s the first time I have been called an Artist!
Some of these ideas we will progress further, but initially we need to focus on getting the electronic circuitry laid out on a reproducible PCB, and optimising the pump and valve interaction to enable a better bubble resolution. Primary in this will be a smaller pump.
Possible future options: Twin circuit with two colours, or even better two colour in one tube Full computer control Control via DMX Synchronised lighting and sound New and exciting structures Flourescent dyes and UV lighting A user interface to inject your own bubble Sign writing abilities Walk through tunnel
(c) M.Pantrey 2010-2013