#garfield Logs

Oct 06 2020

05:49 PM Tom_L: mmm
05:55 PM rue_shop2: yesterday!?
05:55 PM rue_shop2: I havn't mentioned that one in quite a while now
07:32 PM rue_: I forgot a me
07:39 PM rue_ is now known as rue_mohr
09:16 PM rue_mohr: aaaaaand its dark
09:16 PM rue_mohr: got the stuff I set up yesterday mortered in
09:16 PM rue_mohr: have to start right after work or there isn't enough light
09:16 PM Tom_L: you get a little less every day now
09:17 PM rue_mohr: yep
09:46 PM zhanx_workshop: yea this whole dark thing sucks when you are trying to work outside
10:35 PM zhanx_workshop: debating on printing sprayer nozzles or just buying them, i am out of filament
10:36 PM rue_mohr: I have 3 400W metal hallide heads from work
10:36 PM rue_mohr: they were scrap from an upgrade
10:37 PM rue_mohr: need lamps tho, the guys already recycled them
10:37 PM rue_mohr: and poles to put them on
10:37 PM zhanx_workshop: rue is starting a grow op?
10:37 PM rue_mohr: hah, in the side yard?
10:37 PM rue_mohr: I need to find some stuff to make a pole
10:38 PM rue_mohr: not sure how well 400w will do
10:38 PM zhanx_workshop: sticks i heard make good poles
10:56 PM rue_mohr: so does 2" rectangular steel tubing...
10:57 PM rue_mohr: maybe 3"
10:57 PM rue_mohr: plate and a concrete base
10:57 PM rue_mohr: oooh
10:57 PM rue_mohr: I have a problem with this new house thing
11:16 PM aandrew: so rue_mohr (and anyone else too) -- if you had to generate a constant airflow in the 2-10LPM range, what would you do?
11:17 PM rue_mohr: ouch
11:17 PM rue_mohr: cause air density
11:17 PM aandrew: I was thinking of a simple fan from a PC or something blowing into an airtight box where I could then use a needle valve to dial out the airflow I'm interested in.
11:17 PM rue_mohr: I presume you mean a particular value in that region?
11:17 PM aandrew: I know the fan will leak "backward" since it can't compress
11:18 PM aandrew: but that's fine, as long as the air leaving the output is consistent
11:18 PM rue_mohr: gas meter bellows
11:18 PM aandrew: yeah I want to dial in a flow for dozens of minutes
11:19 PM aandrew: gas meter bellows eh?
11:19 PM rue_mohr: they do a switch over thing
11:19 PM rue_mohr: OR
11:19 PM rue_mohr: OR...
11:20 PM rue_mohr: gut a fan, tap it as a flow meter
11:20 PM rue_mohr: put in series with another fan (ducting wise) and feedback loop it
11:20 PM aandrew: well the flow meter Id' use a hot wire anemometer or actual mass flow sensor
11:20 PM rue_mohr: oh pwm a fan
11:20 PM rue_mohr: calibration is the hard bit
11:20 PM aandrew: but yes closed loop is important
11:20 PM rue_mohr: and maybe a straw flow corrector
11:21 PM aandrew: a what now?
11:21 PM aandrew: you mean like a bunch of straws in a tube to create a laminar flow?
11:21 PM rue_mohr: yea
11:21 PM rue_mohr: so you dont get hotspots screwing up the volume
11:21 PM aandrew: right
11:22 PM aandrew: I actually wanted to build a wider version of that (wide enough to go over a doorway) to try to keep flies out of the house
11:22 PM aandrew: but I'd need a hell of an flow to cover the door
11:27 PM rue_shop1: what is a reasonable airflow for a straw?
11:28 PM rue_shop1: P1V1 = P2V2
11:28 PM * rue_shop1 looks at zhanx_workshop
11:29 PM rue_shop1: omg I have one thread trying to design and write 6502 code and the other trying to design a key interface for sorting IO
11:29 PM rue_shop1: their both going in my head, randomly blocking each other
11:30 PM rue_shop1: how well will a software debounce library work if its in a non-consistantly executed main loop
11:30 PM rue_shop1: I need a place for all these modules I keep building
11:33 PM rue_shop1: need to work out my brain
11:51 PM aandrew: heh, that's a good question
11:52 PM aandrew: well, my CPAP machine uses regular old 20mm hose and can go between 5-20something LPM
11:52 PM aandrew: so if I used a 2" PVC pipe packed with straws it should work no matter what
11:54 PM rue_mohr: calibration is the issue isn't it
11:54 PM rue_mohr: how much do you strust strapping it to the top of the car?
11:54 PM rue_mohr: "OK, WERE AT 88MPH... NOW!!"
11:56 PM aandrew: well no
11:56 PM aandrew: calibration isn't hte issue; worst case I'll wire up a mass flow sensor
11:56 PM aandrew: calibrate my sensor against that
11:57 PM aandrew: lol
11:57 PM aandrew: if my calculations are correct... when this baby bits 88mph you're gonna see some serious shit.
11:58 PM rue_mohr: COULD YOU JUST REACH UP AND SEE IF THE FLOW IS STILL LAMINAR?
11:58 PM rue_mohr: :)