View source for EMF 2016 Meeting 2015-12-10

== Fire Pong, anyone? ==

=== Attendees ===

* Ian D
* Toby J
* Mouse

=== What Happened ===

* Discussed puffer design:
** If you're looking for videos on the YouTube,  spell it 'poofer'...
** [http://www.spontaneousfire.com/TOD_firecannons.htm this page] shows simple design a with feed tank, adjustable regulator (30-60 psi) into accumulator, solenoid / hand cranked ball valve to 0.5" barrel with a low pressure regulator from the accumulator side to a pilot. Feed to accumulator is connected for duration of performance... only solenoid is switched to make a puff. Pressure gauge on accumulator side to shoe what's ready to launch / calibrate system
** 1 bar is about 15 psi
** Cost of 0.5-4 bar (8-60 psi) regulator: ~£14, fits calor gas bottles
* Rooting around for parts; found:
** Small (2kg) butane tank in donations which will make a usable accumulator tank for a small prototype. This tank has a 28 mbar low pressure regulator on it (presumably for cooking appliances), which includes a tap to stop flow. The tank is empty, except for a FOUL smelling residue. Under the regulator is a ball/spring value which we may need to push into the tank to get decent flow out of i, but perhaps we can just hold it open with a pin attachment...
** Low pressure guage (2 bar/3-psi)
** Butane cylinder from kitchen has 4.5 kg capacity- it is empty at time of writing
* Butane vs Propane:
** Butane freezes at a higher temperature (about -10C vs -40C in the bottle). For longer performances this may render butane systems more liable to poor performance due to cooling from expansion as the feed tank 8s drained. However, it is a heavier gas, and this might mean it burns more attractively... some experimentation is required
** Butane and propane systems require different regulators to achieve the same flow rate
** Butane 15kg refill from Calor costs £33.75
** Propane 13kg refill from Calor costs £26.95
* Game design
** If small puffers are cheap and we can have lots of them, make a pong game with puffers as the "puck", with big puffers as goals / game wins.
** Multi-pong with LED strips and small puffers as a "cities" (a la missile command).  Small puffer goes off when light "puck" gets past a player, then the city is destroyed.  Once all cities destroyed, game is lost and big puffer goes off.
** Some variation of these
** Need to keep minimum safe distance in mind when designing game!
* We must be mindful not to piss people off by doing risky things in the space or getting the space in trouble with bizspace or what have you.  This means heeding people's requests to stop if they feel we're doing something unsafe and generally being nice about the project
* Where can we do testing?
** Small stuff in Mouse'so garden. 
** Larger tests will need more space... perhaps Sumac front yard?

[[Image:20151210 222759.jpg|400px]]

=== Next ===

* Prototype with small tank from donations
** Goal: find out how much it costs
** Goal: work out what type of gas we want to use
** Goal: work out what sort of pressures work well for accumularor and pilot
** Task: Measure small tank fitting / look up fitting data from specs of this tank type
** Task: Find / buy parts:
*** Feed regulator. Adjustable from 20-100 psi output, with gauge
*** Pilot regulator.  Adjustable for prototyping, lower pressure, with gauge (0-20psi output?)
*** Metal pipe for barrel (1 meter of 22 mm copper plumbing pipe)
*** T joints
*** Hose
* Task: Remind DC to fill butane cylinder for kitchen! (Note: I sent a message to the mailing list already
* Calor don't do large cylinder refills online... fitness out cheap supplier locally for large cylinders

Next Meeting: TBD, but weekly-ish