#robotics Logs

Apr 05 2012

00:13 gaze__ find an old computer with an ISA slot, haha
00:19 Triffid_Hunter gaze__: ftdi isn't gonna keep up with 4MB/s, use usb2 or firewire or ethernet or something like that
00:19 gaze__ right, ftdi's fifo chips are usb2 hi-speed
00:19 gaze__ so it's one way to go.
00:20 Triffid_Hunter ah ok, could work
00:20 Triffid_Hunter dunno how usb is gonna be about sustained transfers at that rate though, it's not really designed for that sort of thing
00:20 Triffid_Hunter ethernet is far more reliable for that sort of stuff
00:22 gaze__ eh, I don't mind bursting much faster
00:22 gaze__ and then buffering
00:22 gaze__ it's just that over 30 seconds, it needs to average to 4 MB/s
00:23 Triffid_Hunter well try usb2 and if that doesn't cut it, go with ethernet
00:41 rue_house 1D gestures, who knows how to code them?
00:41 rue_house rue?
00:41 rue_house yes?
00:41 rue_house can you help me here?
00:42 rue_house no
00:42 rue_house no!?
00:42 e_house points at c
00:42 rue_house ok ok I fix
00:42 e_house turns off the room li
00:42 rue_house see now its bedtime, will you help me now?
00:42 rue_house its awefull late
00:43 rue_house just tell me how, I promise not to try to code it tonight
00:43 rue_house oh ok
00:43 rue_house cool!
00:44 rue_house gestures need to be broken down into phonames, just like vocal sounds
00:44 rue_house how many could there be for a 1d gesture
00:44 rue_house :)
00:45 rue_house hmm, start and direction?
00:45 rue_house add speed and acceleration
00:45 rue_house this seems to make it a lot more than 1d
00:45 rue_house it is
00:45 rue_house ok so, ...
00:46 rue_house you need to break up your gesture
00:46 rue_house right ok
00:46 rue_house you want to profile it by sequence, but by time
00:46 rue_house then how do acceleration and velocity work
00:46 rue_house relative
00:46 rue_house to what?
00:47 rue_house your making this to complex
00:47 rue_house rrrrly?
00:47 rue_house gesture has a start and stop, they can be soft or hard
00:48 rue_house it can start at 0 velocity or ...higher
00:48 rue_house and it can be acclerating or deaccelerating
00:48 rue_house and it can stop
00:48 rue_house you can detect all this
00:48 rue_house sure, easy
00:48 rue_house you need to record the sequence of the events
00:49 rue_house well it sounds like it can be just binary flags so far
00:49 rue_house event based
00:49 rue_house yea, no timeline, just a sequence
00:50 rue_house velocity - 0 + acceleration - 0 +
00:51 rue_house cool, I'll try to code that up tommorow
00:51 rue_house we can use SDL
00:51 rue_house yes
01:46 rizlah http://www.bbc.com/news/technology-17614392
01:46 rizlah Discuss
05:19 KongfuPanda hello robotics people!
06:04 Skwint hello panda
07:15 Steffanx ha KongfuPanda
07:15 KongfuPanda Steffanx, hello
07:16 KongfuPanda Steffanx, what do you think "balonka" is? don't goggle it. It's a Russian word
07:16 Steffanx I've no idea
07:17 KongfuPanda guess man
07:17 KongfuPanda u have no imagination?
07:18 KongfuPanda what comes to your mind when you hear "balonka"
07:20 Steffanx A balcony, because it's looks like "balkon" :P
07:21 KongfuPanda aww
07:21 KongfuPanda it's a small, fluffy dog, usually white
07:21 Steffanx Yay
07:21 KongfuPanda http://sobaker.ru/wp-content/uploads/2011/01/balonka.jpg
07:21 Steffanx Did i fail the test?
07:22 KongfuPanda yeah man
07:22 KongfuPanda no million dollars for you now
07:22 Steffanx Too bad
07:24 Steffanx Don't say you have an ugly dog like that
07:24 Tom_itx http://tom-itx.dyndns.org:81/~webpage/temp/misc/puppy1.jpg
07:25 KongfuPanda :)
07:27 KongfuPanda http://dl.dropbox.com/u/26776513/dog.jpg
07:28 Steffanx uh?
07:29 KongfuPanda it's funny
07:30 Tom_itx not if you're the pug
07:38 rizlah Those dogs with a lot of hair are ugly as hell
07:40 DanFrederiksen they seem to just be playing
07:47 DanFrederiksen robot dogs don't bite : )
08:03 Skwint why on earth would I go to the trouble of creating a robot dog
08:03 Skwint and then not give it the ability to bite?
08:41 Skwint The power switch on my car has broken
08:41 Skwint and after taking it to bits it appears that although it has two sides, only one side ever had the copper bit in that makes connections
08:41 Skwint so I don't understand what the wires attached to the other side are for - it's like the ship this thing with dangling wires :/
08:42 wint is conf
08:52 DanFrederiksen Skwint, maybe get the machanics manual for your car
08:53 Skwint it's a small RC car, not a big one you drive in
08:53 Skwint the manual explains in great detail how to change the battery :p
08:53 Skwint if I'd broken a real car I wouldn't be asking about it in here :)
08:53 DanFrederiksen hehe ok
09:12 rue_house Skwint, why not?
09:13 rue_house Skwint, take us a pic of hte switch and wires, dont zoom in crazy, see if we can work it out for ya
09:15 Skwint it's OK thanks - it's so simple an object that there's nothing to really work out
09:15 Skwint my best guess is that a piece of copper has become lost at some point
09:17 Skwint in theory it's a 3 position switch - off / slow / fast
09:17 Skwint and I never did manage to work out what the connections on two of the wires were - it appears to be because there never were any
09:17 Skwint I might try connecting them at some point and see what happens :)
12:31 tsmeow-afk lets one of her internet domains fold, since it was set up for intelligent software, and no one wants
12:37 Steffanx uh?
12:38 katsmeow-afk what word did you not understand?
12:39 weebl quick question, a proportional controller would simply be the difference between input and desired output divided by a gain right?
12:40 katsmeow-afk i'd agree
12:41 katsmeow-afk altho adding gain, gain slope, etc might cause someone to call it a PID controlelr too
12:42 katsmeow-afk to me, and ymmv, proportional means only "it's analog control, any position or movement tween 0 and 1", where not propotional means "it's either full on power or nothng"
12:55 weebl I'm working on an assignment where I am going to show the difference between p, pi, dp and pid and how it affects how a car follows a heading
12:57 katsmeow-afk ah, interesting
12:58 weebl so I am just trying to separate the various aspects of the PID now
12:58 katsmeow-afk i wold be interested in the overshoot and g-forces involved in correcting overshoot, possibly energyy waste in overshoot
12:58 katsmeow-afk great project, imo
12:58 weebl yeah its fun
12:59 katsmeow-afk because it demonstrates, possibly, the benfit of eliminating error instead of correcting the error
12:59 weebl yeah
12:59 katsmeow-afk smart :-)
13:00 weebl so pseuodocode wise p controller would just be error * gain, where the gain is less than 1
13:00 katsmeow-afk that's what i figured you might go for, yeas
13:01 katsmeow-afk how far away from overshoot you make gain begin, i dunno
13:01 weebl and then pd would be a gain that is decreasing epending on how large the error is
13:01 katsmeow-afk i agree
13:01 katsmeow-afk would this be a avr software download then?
13:01 weebl arduino
13:02 katsmeow-afk almost the same
13:02 tsmeow-afk
13:02 weebl got told of by my supervisor for wanting to do stuff with standard afk
13:02 weebl too much work
13:02 weebl *AVR
13:03 katsmeow-afk right, gotta buy the physically biggest and most expensive, and largest software platform, might as well use windoze :-/
13:03 weebl hahah, what are you working on?
13:04 katsmeow-afk atm, some environment control stuff
13:04 weebl ok
13:04 katsmeow-afk and irl: plumbing
13:05 katsmeow-afk and i need my mini-vac to have a low-pressure-high-volume blower port as well
13:07 weebl so much mechanics, I envy you, I strapped an arduino to an rc car
13:07 katsmeow-afk i radio-strapped a desktop puter to an rc car
13:08 katsmeow-afk means the car stays on the ground, and i sit at the puter
13:08 katsmeow-afk vs the car being on the desk, or me being on the ground
13:08 katsmeow-afk :-))
13:10 weebl nice
14:04 katsmeow-afk omd, on radio, a church just invited kids to be in a field Sunday, where they plan on dropping 4000 eggs from a passing plane for the kids to catch
14:04 katsmeow-afk shades of turkey drop WKRP
14:13 KongfuPanda woot?
14:13 KongfuPanda like for african kids to catch food?
14:14 katsmeow-afk catch it? launched from a plane at 160mph,, catch it?
14:15 katsmeow-afk i'll be surprised if the eggs don't break bones
14:22 Steffanx What a waste
14:23 Steffanx Seriously .. a church?
14:24 Steffanx Eggs have nothing to do with the easter .. so why a church does something like that?
14:26 katsmeow-afk same reason i guess churches say jesus was born in winter <shrug>
14:29 aod Steffanx: actually, they do
14:30 aod egg is the symbol of life
14:30 aod and easter is all about resurrection
14:30 Skwint it could be the churches answer to having banned contraception
14:30 katsmeow-afk but, egg is a Spring pagan thing
14:30 Skwint they need to decrease the population somehow and 170mph chocolate should do the trick
14:30 katsmeow-afk ditto "xmas trees" and mistletoe
14:31 Steffanx aod, the 'christian' easter ?
14:31 Skwint I saw a 340mph radio controlled plane recently - that was funny ;)
14:31 Skwint eating chocolate jesus eggs brings you closer to enlightenment
14:32 KongfuPanda Steffanx, what is "papera" ? it's italian. Guess
14:32 Steffanx I have nooo idea
14:32 KongfuPanda guess man
14:32 Steffanx WHY?
14:32 KongfuPanda because it's a funny word
14:33 Steffanx Google images told me it's a duck :P
14:33 Steffanx i win
14:34 KongfuPanda no no, it's a duckling
14:34 Steffanx rubber duck
14:36 katsmeow-afk kool, just ordered parts for qty100 [optocoupled mosfet 120v switches for miniflourescent lights] and qty100 [programmable current regulators for 5mm led strings] and qty50 [programmable current regulators for 1w and 3w leds] ..... all for ~$25.00usd
14:37 Steffanx Party
14:37 tsmeow-afk da
14:38 Skwint you are good at that stuff kats - you should make a shop based on getting good deals and selling them again :p
14:38 katsmeow-afk sure, ecept if people wanted these things, then they'd be snapping up the good deals before i get to them, no?
14:39 Skwint only if they are as good at it as you
14:39 katsmeow-afk i once bought some 74ABT374 for $0.001 each, that's right, 1/10 cent each
14:39 Skwint people make money trading on ebay...
14:40 katsmeow-afk got two 7603 scopes for 99 cents , and one of those was free s&h
14:40 katsmeow-afk got a 5110(?) scope for paying s&h on it, that was the one i tried to get rue to grab,
14:41 katsmeow-afk but agian, no one wanted a free scope
15:03 home_ is it weird to have dreams of control systems?
15:05 katsmeow-afk no
15:05 Steffanx yes
15:06 sw0rdfish hey katsmeow-afk... is it illegal for ppl to be on .mil sites?
15:07 Steffanx for you.. yes
15:08 katsmeow-afk no
15:09 Steffanx duck[ipod] stop it..
15:09 katsmeow-afk like ALL gov sites, they'll do their best to log, track, hack, etc you
15:11 duck[ipod] Steffanx: I'm done :P
15:11 katsmeow-afk and, keep in mind, some data on mil sites is deliberate misdirection, such as the corregated submarine hull stupidity
15:12 sw0rdfish yeah
15:13 katsmeow-afk then there was the stupidity they themselves fell for: "the shortest trajectory for a cruise missile is a straight line" ,, they disregarded the earth is round, which led to some missiles launching and then diving into the ground
15:14 katsmeow-afk the shortest route to China is NOT thru the core of the planet
15:14 katsmeow-afk unless you're a neutrino
15:15 Steffanx I am!
15:15 Steffanx I just took a long path than the other 'particles' so i'm delayed a little
15:16 katsmeow-afk and remember they called the early Iraq etc missiles "scuds" as a polite term for "they're shit", because the guidance system caused the missile to corkscrew around,, turns out that was the easiest and best way to avoid the usa and Israeli antimissiles from shooting the "Scuds" down
15:19 katsmeow-afk and the misinfo about the airborne laser system needing 19 C17 cargo planes worth of "fuel" for each laser flight? each laser flight cannot carry 19 C17 planes worth of cargo, period, so that's false too
15:20 katsmeow-afk so read stuff online with large grains of salt
15:21 sw0rdfish lol, I see.
15:25 Steffanx Yes, so just do the same iwth everything you just said katsmeow-afk ? :P
15:25 katsmeow-afk well, without the recursion
15:27 katsmeow-afk afk to do things irl
15:28 Steffanx You're always afk
16:59 rizlah She is very busy.
16:59 rizlah Forever afk
18:03 weebl gah I keep on confusing myself
18:04 weebl my proportional controler turns out to be a proportional derivative controler
18:04 weebl or I think it does
19:37 tsmeow-afk wonders what Tom did to appease the angry sky gods yesterday,, because theya re here
19:50 sw0rdfish lol ^^
20:16 rue_house hello
20:16 tobbor Hello rue_house
20:16 rue_house hi tobbor, how was your day
20:16 rue_house !seen nothing like it
20:16 tobbor I have never seen nothing like it
20:17 rue_house one of those eh?
20:17 rue_house hi rue
20:17 rue_house hi
20:17 katsmeow-afk !seen anything like it ?
20:17 tobbor I have never seen anything like it ?
20:17 rue_house workin tommorow then, geez
20:18 rue_house hi kat
20:18 katsmeow-afk hi rue
20:19 katsmeow-afk ...
20:19 rue_house I'm working on my gesture library
20:19 katsmeow-afk i thought the social pleasantries should last longer
20:20 tsmeow-afk looks for a ges
20:20 rue_house for definition and detection of gestures on a 1d input
20:20 katsmeow-afk 1D ? no up or down, just a point?
20:20 rue_house 1d left and right
20:20 rue_house -infinity to +infinity
20:21 katsmeow-afk so a horizontal line is a gesture?
20:21 rue_house a path along it
20:21 katsmeow-afk ok...... i move my foot along a hline, is a gesture of what?
20:22 rue_house how baout yu move the pitch of your voice up and down
20:22 rue_house to turn on a light
20:22 rue_house :)
20:22 katsmeow-afk woooOOOOOoooo turns on a light
20:22 Tom_L ask hawkings what he does
20:23 tsmeow-afk suggests morse
20:23 rue_house :( I dont care if you all think its astupid idea, I'm doing it anyhow
20:23 katsmeow-afk nono
20:23 rue_house yesyesyes
20:23 tsmeow-afk suggests morse code pitch or beeps or someting,, it's a
20:23 rue_house you cant stop me
20:23 Tom_L touchy
20:23 rue_house I'm making a generic 1D gesture system
20:24 katsmeow-afk once i understood, i was trying to help :-(
20:24 Tom_L yeah i noticed the two of you discussing it
20:24 katsmeow-afk i still dunno what 1D means
20:24 e_house eyes kat.....
20:24 rue_house single value
20:24 rue_house goes up and down
20:24 rue_house think of a line sensor mounted vertically on a lightswitch plate
20:25 rue_house and different patterns of motions with your fingers right infront of it make it do different things
20:25 katsmeow-afk Jordie's visor, which they took off the Knight Rider Transam
20:26 rue_house so far, a presence is composed of a velocity and an acceleration
20:26 rue_house a stroke is a sequence of prescences
20:26 rue_house and a gesture is a series of strokes
20:27 katsmeow-afk do you have these line scanners that you need to communicate with?
20:27 rue_house I want to use it on other things first
20:27 tsmeow-afk ponders rue gesturing at a barcode re
20:27 rue_house hmm , I do have a tonne of them around
20:27 rue_house grocery store ones
20:27 katsmeow-afk don't look into them
20:28 rue_house like a square foot big
20:28 katsmeow-afk you have one or more on your bot position detector thing too
20:28 rue_house 5 elements should be enough for a switch
20:29 rue_house anyhow, I'm not sure how well it'll work, so I'm gonna make it and play
20:30 Tom_L oh rue_house
20:30 rue_house 8-|
20:31 Tom_L crap
20:31 Tom_L i erased it
20:31 rue_house :/
20:31 katsmeow-afk odd request
20:34 Tom_L oh...
20:34 Tom_L http://www2.electronicproducts.com/Researchers_develop_robotic_hand_with_tactual_sensation-article-fajb_robotic_hand_april2012-html.aspx
20:36 katsmeow-afk http://duckduckgo.com/?q=electric+motors+with+twisted+string+
20:38 katsmeow-afk http://www.gizmag.com/robotic-hand/12029/ beats http://www2.electronicproducts.com/Researchers_develop_robotic_hand_with_tactual_sensation-article-fajb_robotic_hand_april2012-html.aspx
20:40 katsmeow-afk it makes gestures too : http://www.squse.co.jp/robot/img/pp3.jpg
20:41 rue_house brain not working, must nap
20:42 katsmeow-afk http://www.gizmag.com/sand-flea-jumping-robot/21989/
20:45 rue_house saw that
20:49 katsmeow-afk i need one to paint the 45 degree roof sectons
20:49 katsmeow-afk it's 28ft off the ground to the eaves on the south wall
20:51 katsmeow-afk is there a V8 engine that does not have any power stroke with a compression stroke occuring same time?
20:51 katsmeow-afk wait
20:51 katsmeow-afk is there a V8 engine that does not have any power stroke with a intake stroke occuring same time?
22:09 peeps[lappy] does a tool like this exist: electric torque wrench with torque sensing, and adjustment like a 7 segment display with up down arrow buttons to adjust specified torque?
22:09 peeps[lappy] or other similar interface to specify torque
22:12 Triffid_Hunter peeps[lappy]: I'm certain they exist, also certain they're rather expensive
22:13 Triffid_Hunter peeps[lappy]: http://www.gearwrench.com/catalog/torque_wrenches/electronic_torque_wrench/
22:14 peeps[lappy] yeah, like that but also powered
22:14 Tom_itx it's human powered
22:15 Tom_itx :)
22:16 peeps[lappy] http://www.nibtorque.com/id29.html
22:16 peeps[lappy] that looks awesome
22:16 peeps[lappy] haven't found a price yet
22:17 Triffid_Hunter peeps[lappy]: that's how you know it's expensive
22:19 peeps[lappy] but how expensive
22:50 peeps[lappy] i guess the best thing after thinking about it, would just be a digital torque wrench like Triffid_Hunter linked, but with a low torque cordless motor for fast spin on and off.
22:54 peeps[lappy] or hell, a flip out handle at the end that could be spun around quickly to spin on and off.
23:11 katsmeow-afk why not a motorised ratchet, they make them with air motors, so use an electric, and calibrate output torque vs motor current, then display it <shrug>
23:13 katsmeow-afk [ChanServ PING reply]: 14 secs
23:13 katsmeow-afk . 10:55:19pm 04/05/12 Thursday tobbor Remote host closed the connection .
23:14 rue_house yes
23:14 rue_house tobbor is on a 1/day reboot script cause freenode is unstable
23:14 rue_house !time
23:14 tobbor My watch says its 21:06 Thu Apr 05 2012
23:15 rue_house I wnder if its possable to rip the center wire out of a guitar string and use it with a smaller wire as a pull-cable
23:15 katsmeow-afk ??
23:20 thylne Has anyone here successfully built a robot with tank treads?
23:21 rue_house not real ones :(
23:21 katsmeow-afk but i know where you canget some authentic ww2 treads
23:21 rue_house kaaaaat? can I borrow some tank treads?
23:21 katsmeow-afk yeas
23:21 rue_house :) your the best
23:22 katsmeow-afk <blush>
23:22 rue_house I should book a holiday and come down
23:22 rue_house it would be good ot get away
23:23 katsmeow-afk but it wold be better to get away from here!
23:23 rue_house when isn't hurricane season down there?
23:23 katsmeow-afk yu may wanna keep in mind, i still have no running water, and my back is badly re-injured, i can't do much
23:24 rue_house thought you had a well?
23:24 katsmeow-afk it isn't hurricane season right now
23:24 katsmeow-afk nope
23:24 katsmeow-afk *had* county water
23:24 rue_house thought you also had municipal water
23:24 rue_house did they turn it off?
23:24 katsmeow-afk i have a small creek that runs in rainey season
23:24 rue_house and its not rainy now!?
23:25 rue_house my yard is a bloomng swamp
23:25 katsmeow-afk yeas, they turned it off, i was gone 2 months, came back a day late to pay it, but had that flat tire, they could have called the turnoff guy to tell him not to, but they figured on making another $40 from me by turning it off
23:25 rue_house hard to walk across the lawn without going down to your ankles
23:25 katsmeow-afk it is rainey season
23:26 rue_house make a wrench and go turn it on
23:26 katsmeow-afk it's not rainey season here in late summer early fall, we can go 3 months with no rain
23:26 rue_house you must have some 5/8" rebard and 1" flatbar
23:26 katsmeow-afk it's pinned with a lock, they check it every day, would have been cheaper to just leave it on for me
23:27 rue_house hmm, ours are at the bottom of a 18" hole...
23:27 katsmeow-afk the valve and meter? 12 inch hole here
23:27 rue_house no meters here
23:28 rue_house so you have paid and your waiting or you cant get there?
23:28 rue_house how often do youhave to pay for water?
23:30 katsmeow-afk i am not going to pay the $40 turn-back-on fee, not going to pay the $50 reconnect fee, i did pay monthly water fee, i am not paying anything tot he water company again
23:30 rue_house still got many a hwt?
23:30 katsmeow-afk if my back will cooperate, i'll be storing up 3000 gallons of water outside, and 500 gallons of water inside, from the creek, during rainey season
23:31 rue_house gutter too kat, all rifs water was gutter
23:31 rue_house getting any rain?
23:31 rue_house got a booster pump?
23:31 katsmeow-afk no, i lost ~8 prime hwt , left dwon n Fla
23:31 rue_house damn
23:32 katsmeow-afk got a cheap 1/2 hp and cheap 3/4 hp pump, already got water pipe and 10-3wg in conduit down to the creek
23:32 rue_house if its raining set up the gutter
23:32 furrywolf I drilled my own well... fun project.
23:32 rue_house furrywolf, your back again...
23:33 katsmeow-afk rock , chert, and heavy clay here, it would be too much fn
23:33 katsmeow-afk furrywolf has back problem too?
23:33 rue_house maybe, why are you here again furrywolf
23:33 furrywolf katsmeow-afk: http://fw.bushytails.net/wellbit01.jpg it would handle sandstone, but chert might be too hard.
23:34 furrywolf rue_house: someone suggested I ask here for information on hydraulic pump design books. no one could think of any.
23:34 rue_house furrywolf, did you weld that?
23:34 rue_house furrywolf, for making a hydraulic pump?
23:34 rue_house or for making hydraulic systems?
23:34 katsmeow-afk how did you lift it back up? or was it a one-shot pound-in?
23:35 furrywolf yes, I welded it, and yses, for making a hydraulic pump.
23:35 rue_house furrywolf, your a pretty good welder!
23:35 rue_house nobody Iknow makes hydraulic pumps....
23:35 katsmeow-afk hydraulic pump = water pump, or piston air pump, with caveats
23:35 furrywolf katsmeow-afk: that is a rotary drill bit. it goes on the end of a rotating drill string (1" sch40 galv pipe, in this case), with drill fluid pumped down the pipe.
23:36 rue_house well you did it right
23:36 katsmeow-afk that would make a really big hole
23:36 furrywolf the bit breaks up the material, which is flushed out of the hole by the drilling fluid.
23:36 rue_house was the drill fluid kitty litter base?
23:36 katsmeow-afk you drop it with/inside the casing?
23:37 katsmeow-afk how much pressure volume you need for the ydraulics? and water or real hydraulic fluids?
23:37 rue_house is it for pumping drill fluid?
23:38 rue_house my budy just borrowed a drill rig
23:38 katsmeow-afk for hitting rock or chert, you need real tubing, not water pipe, waterpipe is cheap stuff
23:38 rue_house I think it uses a 2 piston pump
23:38 katsmeow-afk i think the furry wolf qui
23:38 katsmeow-afk t
23:38 rue_house furrywolf, hello?
23:39 furrywolf sorry, talking in multiple places at once.
23:39 katsmeow-afk ok, we'll periodically ignore you too then, you'll understand
23:39 furrywolf for most wells, you set casing after drilling the hole. you drill to the desired depth, remove the bit, then drop in the casing before the hole caves in.
23:40 rue_house hey I'm writing code for gesture detection right now you know
23:40 furrywolf I mysteriously am no longer the founder of one of my channels, so trying to figure that out, not just chatting. heh.
23:40 rue_house furrywolf, you were gone for a while, maybe it was handed over to someone by the ops
23:42 katsmeow-afk wow http://fw.bushytails.net/checknoisesratherthankeepdriving.jpg
23:43 furrywolf for the hydraulic pump, it'll be real hydraulic fluid. the odd design requirements are ultra-low input rpm (30-120), very high efficiency, and funky variable displacement designed to give a constant input torque rather than constant pressure or standard requirements.
23:43 rue_house someone didn't jump on the tire wrench before leaving
23:43 furrywolf rue_house: yep. not me, fortunately. :)
23:44 rue_house furrywolf, input torque is proportional to ouput pressure for every pump I know
23:44 furrywolf rue_house: not on variable displacement pumps. :)
23:44 rue_house so you want a constant pressure variable displacement pump...
23:44 furrywolf input torque is output pressure * displacement setting
23:44 rue_house yes
23:44 katsmeow-afk oh, if it's odd design, i can't afford it, but i was going to suggest 1) power steering pump B) one of those lil 12v/120v hydraulic kits that run some car lifts in garages
23:44 rue_house thats still proportional
23:44 furrywolf no, I want a constant input torque, that will adjust its displacement, regardless of output pressure, for a constant input torque.
23:45 rue_house ...
23:45 furrywolf if the output pressure doubles, it will halve its displacement to maintain the constant torque.
23:45 rue_house thats what I said
23:45 katsmeow-afk so use the 12v version, and modulate the 12v and current to do what you want
23:45 rue_house the output pressure cant double on a constant pressure pump
23:45 rue_house tho
23:46 rue_house if the output flow is capped the input torque will drop to zero when it comes up to pressure
23:46 rue_house ...
23:46 rue_house me thinks
23:46 furrywolf I'm not building a constant pressure pump.
23:46 rue_house na, I'm sure that the input torque stays the same
23:47 rue_house I'm saying, for the best my mind is working now, you get a constand input torque pump and the output pressure is constant
23:48 rue_house can we find rpm/torque graphs for constant pressure and flow pumps?
23:48 rue_house who makes them
23:48 furrywolf ... I'm not building a constant pressure pump!!
23:48 rue_house does devilibis make hyd pumps?
23:49 rue_house furrywolf, I hear this from you: I want a constant current going into a motor but I dont want the motor to be constant torque
23:50 furrywolf I want a hydraulic pump where the input torque is constant regardless of the output pressure. this is a simple variable displacement operation. I'm looking for information on actually building it. :P
23:50 rue_house draw a torue/rpm graph of the pump you want :)
23:50 rue_house so, if the output pressure drops out, you want the displacement to go up to max
23:51 rue_house if the output is capped, you want the displacement to go towards "zero"
23:51 furrywolf torque = flat line. rpm = 30-120 rpm, with no effect on the torque. output pressure = as high as it can be, while maintaining the required input torque setting.
23:51 furrywolf no. if the output is capped, I want the input torque to stay constant as the pressure rises, until the relief valve opens.
23:52 rue_house katsmeow-afk, do you read this like I do?
23:52 rue_house furrywolf, ok, now , on that graph show me the flow/pressure
23:53 rue_house or it'd have to be a seperate graph
23:54 furrywolf ... why is this difficult to grasp? displacement ~= 1/pressure. if the pressure doubles, the displacement halves, so the torque stays the same.
23:55 furrywolf at a given pressure, if you double the rpm, the flow doubles.
23:56 home AH
23:56 home too much information.. LOL
23:56 furrywolf the variable displacement control isn't the hard part... the very low rpm and high efficiency requirement is what makes it hard.
23:57 furrywolf most hydraulic pumps and motors use sliding metal surfaces for the valves, that ride on a fluid film.
23:57 furrywolf this is inefficient and ineffective at low rpm.
23:57 katsmeow-afk i have not seen those with sliding *valves*, but all use pistons that slide in cylinders
23:58 katsmeow-afk some use slippers in rotary pumps
23:58 katsmeow-afk so use pistons and ball valves?
23:58 katsmeow-afk spring loaded ball valves
23:59 katsmeow-afk intake sucks a ball valve open, exhaust pushes the exhaust valve open
23:59 home is these about pneumatics?
23:59 furrywolf the other problem is most/all (that I've seen) variable displacement pumps use "shoes" riding on the swashplate, again supported by a fluid film... and again bad at low rpm.
23:59 katsmeow-afk he said hydraulic