#robotics Logs

Jul 28 2012

00:01 katsmeow-afk plus polarity
00:01 katsmeow-afk and intensity
00:01 rue_shop all thats beyond my effort for an analog circuit
00:02 katsmeow-afk on a positive voltage drive, the kick will go neg, then often above the positive supply too
00:02 katsmeow-afk depends ont he motor, current, etc
00:03 katsmeow-afk umm, ok, i used a programmable digital pulse timer (a C64) for desired rpm, 3 transistors, and a 74LS122 (?)
00:04 katsmeow-afk the 74LS digital one-shot was the entire feedback system, the puter just set the desired rpm
00:05 katsmeow-afk it pwm'd the motor, it wasn't analog cept for the current source of the oneshot timer
00:05 katsmeow-afk that was just one transistor
00:10 rue_shop wow I have a board here that uses 2 A3952 drivers for _1_ stepper motor
00:21 katsmeow-afk my brain just shut off
03:13 rue_mohr off is which way?
07:26 standoo hi
07:26 standoo i like robotics
07:26 seravitae you're probably in the right place then
07:26 standoo seravitae: thanks
07:26 standoo standoo: just starting though
07:27 seravitae I can't even drill a hole where i marked it to be, so dont look at me..
07:27 standoo seravitae: you any good in electronics?
07:28 seravitae I wouldnt say good
07:28 standoo well i'll ask anyway
07:28 seravitae i can design a small circuit, pcb, solder it together... not analog stuff though.
07:28 standoo how true is it that an appliance will draw as much current as needs?
07:29 standoo and if there is more current available, eg a dc adapter which is able supply a higher current than needed by the appliance, what will be the consequences?
07:30 seravitae in theory, if you have a device that draws 1A, it will draw 1A, no matter whether the supply is 1A or 100A.
07:31 seravitae in practice, it *should* only draw that much. in 99% of cases it will.
07:31 seravitae the other 1% of cases, it might be limited by the PSU current limiter (bad!!) and might draw too much current if plugged into a larger supply. However that is very very rare and probably only found in third world designed circuits
07:32 standoo thanks for the confirmation
07:33 standoo if i put a diode between the appliance and power supply, will the maximum forward current matter in this case?
07:33 seravitae np
07:33 seravitae it might but i am not sure. placing a diode in series will cause a voltage drop due to the diode
07:33 seravitae it would make me think that the device would thus probably use less power as well.
07:33 standoo yeah i know about that
07:33 jon777 I LOVE THIS CHAT
07:34 standoo it's the current which i'm unsure about
07:34 seravitae the forward current would only matter if the diode's forward current was lower than the desired current flow, in which case you'll let the smoke out of the diode
07:34 jon777 Its great when you're trying ot start a fire
07:35 jon777 Does anyone know the battery/knife/paperclip trick for starting a fire?
07:35 standoo desired current flow = current used by the appliance in my case?
07:36 seravitae yes
07:36 seravitae basically
07:36 seravitae don't use a half-amp rated diode on a twelve amp circuit :)
07:36 seravitae unless your goal is smoke.
07:36 standoo let's say i wanted to use a half amp diode, then the solution would be use 2 of them right?
07:37 standoo hehe
07:37 seravitae potentially, i belive you can use diodes in paralell for more current, but diodes are cheap, even with large amounts of current
07:37 seravitae and im not sure if there would be any wierd issues due to differences in the diodes
07:38 standoo cool thanks
07:38 standoo my goal: make an army of robots
07:39 seravitae my goal: get my computer working
07:39 seravitae so far no luck!
07:39 standoo isn't it working?
07:39 seravitae it works, it just overheats.
07:40 standoo heat sink problem?
07:40 seravitae not sure yet.
07:40 seravitae i thought it was poor ventilation, so i added a 180mm fan to the case.
07:40 seravitae two of the CPU's seem to be running at okay temps, but the other two are scortching hot.
07:41 seravitae so i'm going to throw another 2x 180mm fans right over the top of them
07:41 standoo what cpu is that?
07:41 standoo server?
07:42 seravitae yeah, quad opteron 6272
07:42 standoo man, i wish i had a server
07:42 seravitae well this isnt for serving, i have a NAS/server for that
07:42 seravitae this is just for computing stuff.
07:42 standoo computing what?
07:43 seravitae I do lots of computational heavy stuff. rendering, molecular dynamics simulations, financial/statistical math.. probability stuff for NP complete problems...
07:43 standoo oo
07:43 standoo academic?
07:44 seravitae sorta yeah.
07:44 standoo are u from oz?
07:45 seravitae yeah
07:46 standoo from nz
07:47 seravitae cool
07:48 standoo the only thing that is stopping me from setting up my web server is the difficulty of getting a good enough internet connection
07:50 standoo what kind of engineering you do?
07:56 standoo what kind of engineering you do?
07:57 Skwint I wish I could be from nz
07:57 Skwint I'd even settle for being from oz ;)
07:57 standoo y so?
07:57 Skwint I love new zealand, but they both have a much more relaxed and easy going attitude to life than the UK
07:58 standoo come over then
07:58 Skwint fjordland is just amazing though
07:58 Skwint I'm a software engineer - you don't need me enough :(
07:58 Skwint if I was a beauty therapist I'd be in like a shot :p
07:58 standoo hmmm, maybe i'll need you
07:58 standoo hehe
07:59 standoo what do you specialize in?
07:59 Skwint low level C++
07:59 Skwint I can do all sorts, half a dozen platforms, mobiles, various languages
08:00 Skwint but pure C++ is the one I'm good at
08:00 Skwint I'm in a game - BIAB
08:00 standoo how about C?
08:16 Skwint that's where I started
08:16 standoo ah
08:16 Skwint and I've done optimized software graphics in C (well, in C++, but one single function of C++ is basically C)
08:17 standoo i'm a amateur only
08:17 Skwint I'm an amatuer in this channel - I've made one robot to learn what was involved
08:17 standoo i'm an amateur in programming
08:18 Skwint I learnt to code in ... um ... about 1980 ;)
08:18 standoo i learnt 5 years ago
08:18 standoo self taught
08:19 standoo i understand the code, but never could get the right terms to communicate to another programmer
08:21 standoo what robot did you build?
08:26 Skwint I hacked an RC car
08:27 Skwint and stuck an axon2 on it and made it drive around with an IR range finder
08:27 Skwint sadly, the range of the range finder isn't enough so it mostly managed to detect what it was going to crash in to rather than avoiding anything
08:28 Skwint I have a sonar unit now which I wanted to try, but I haven't go round to it
08:29 standoo why don't you just get a kit and play around??
08:29 Skwint not sure I'd learn anything with a kit
08:29 standoo yeah
08:30 standoo since you already had the programming background already
08:30 Skwint it was electronics I needed to learn
08:30 standoo what you needed was the mechanical/electronic side to learn
08:30 Skwint tbh the mechanical side of hobby robotics is about as sophisticated as playing with lego :p
08:31 Skwint that's probably not always true, but ... good grief ... 4 screws and a couple of wheels ;p
08:33 standoo have you heard about the raspberry pi boards?
08:55 Skwint yes, but I don't know much about them
08:55 Skwint they sound interesting
08:56 Skwint certainly save me worrying about being back in the 8 bit world all the time :p
08:56 Skwint but I have my axon2 connected over bluetooth to my android phone so I already have a fairly strong processor available if I want it
09:02 standoo i was thinking of the best way to put a webcam onto a robot
09:04 standoo thinking of getting one of those smallboards with a wifi to stream the webcam output through wifi
09:04 standoo at the same time, the board can also send serial commands to the arduino board
09:46 Skwint probably depends on what range you want the robot to have
09:47 Skwint if I felt that way inclined, my android phone has a video camera and 3G and could go round half the planet sending me video back
09:47 Skwint but it would be a much more expensive bandwidth
09:48 standoo yeah
11:22 rue_mohr "Some people buy heavy equipment to get work done, some people buy heavy equipment for fun, some people buy light equipment and have fun getting work done"
11:22 rue_mohr http://hackaday.com/2012/07/28/excavate-your-basement-using-rc-equipment/
13:47 katsmeow-afk seravitae : liquid cooling
13:49 katsmeow-afk use germanium or schottky diodes for lower drop, or for extremely low drop use a hall effect current sensor and IRF1404 set up like active rectifiers
13:53 tsmeow-afk built her house a lil like /excavate-your-basement-using-rc-equipment/ , ~4x4ft of wall area at a
13:53 katsmeow-afk in a way, so was Egypt's Grand Aswan Dam
13:54 katsmeow-afk the main watertight core of that damn was built *after* the bulk of the dam was already built
14:00 katsmeow-afk somewhere, i have video of the drilling rigs making a series of bores across the river in the center of the dam, they drilled holes to bedrock, which were then filled with concrete
14:01 katsmeow-afk making a concrete curtain wall from river bank to river bank, without ever building a single concrete form
14:02 katsmeow-afk but the main reason was the river bottom would never have supported the stucture needed for a single truck to make the watertight core, so they poured a couple 100 ft deep of dirt first
14:03 katsmeow-afk the dam is over 6000 ft long
16:51 rue_shop "Is this creature intelligent?" "no..." "Damn." "why?" "I been trying to communicate with it for 18 hours now."
16:52 anannie rue_shop: Didn't the guy's subconscious reply?
16:55 GuShH winter days are entirely useless.
19:03 katsmeow-afk "we've left pheremones and pee all over the place all night, and no one has shown up to reply"
19:55 anannie Hi katsmeow-afk
21:03 jon777 I love this chat
22:46 rue_mohr todays ebay item is a bunch of 1n914 diodes!
22:53 tsmeow-afk
22:54 rue_mohr the jester came by and we got the arduino tested for the reprap
22:54 tsmeow-afk nods a
22:55 e_mohr checks that this IS cat and not a bobblehead man
22:55 tsmeow-afk nods at the valid
22:56 rue_mohr 'love the neighbour' ?
22:56 katsmeow-afk gross
22:56 katsmeow-afk eww
22:56 rue_mohr ok your real
22:56 katsmeow-afk you're
22:57 rue_mohr any progress on anything today?
22:57 rue_mohr healing maybe?
22:57 katsmeow-afk no
22:58 katsmeow-afk i keep running into the rule made just for me that i cannot have window fans (so the living room gets to 140F in daytime), plus half my stuff is still in moving boxes and upstairs, etc etc
23:08 rue_mohr http://en.wikipedia.org/wiki/Solar_chimney
23:09 katsmeow-afk yeas, cannot do that when it's raining, the neighbor won't let me finish the elevator shaft
23:09 rue_mohr :(
23:09 katsmeow-afk plus, that means the cellar door must be open
23:10 rue_mohr I didn't say it with any preconcieved notions that it was definitly possbale
23:11 katsmeow-afk when it works, it works great, there's quite a wind
23:11 katsmeow-afk the elevator shaft is meant to be used that way, but the legal system here has screwed it up for me
23:12 katsmeow-afk if any dog wants to come in the cellar door (that door was mentioned specifically in court), i must allow the dog inside to bite me as much as it wants, in my own house
23:13 katsmeow-afk not allowing it is a felony
23:13 katsmeow-afk i was told i would be facing 10 years *to start with*
23:14 katsmeow-afk plus, if i did not enjoy getting dogbit, they'd put me in a institution to find out why
23:14 katsmeow-afk basically, if i haveto shoot in self defence again, i may was well kill myself
23:16 rue_mohr shoot the DA
23:17 rue_mohr then you get free room and board for life
23:17 katsmeow-afk they'd still put me away for life
23:17 katsmeow-afk and all the raping and dog attacks i want?
23:18 rue_mohr if you play your cards right you might get a padded room to yourself?
23:18 rue_mohr kat, you know I cant help
23:18 rue_mohr you know I want to
23:18 katsmeow-afk i know
23:19 rue_mohr talking about it is like hanging a carrot on a stick tied to a donkey... wait... this requires a diagram...
23:19 rue_mohr regardless the ends would be that I come over and shoot the DA for you
23:20 katsmeow-afk sure you would
23:21 rue_mohr it would be a challange, I'm taxed to hit a barn door from 100' with a rocket launcher
23:22 rue_mohr even if its still on the barn
23:23 tsmeow-afk
23:23 rue_mohr oops, I fried my refried beans, so... what are they now?
23:23 katsmeow-afk friedrefried
23:26 rue_mohr http://www.ebay.ca/itm/100-PCS-WHOLESALE-CELL-MOBILE-PHONE-STRAP-STRING-LANYARD-DANGLE-CORDS-/290750854505?pt=PDA_Accessories&hash=item43b219f569
23:26 rue_mohr ?
23:28 katsmeow-afk i dunno, they have that anti-theft color that everyone will ridicule you for
23:28 rue_mohr 100 for 1.00?
23:30 katsmeow-afk so the cord is under 1 cent per foot, that's ok
23:51 parco hi, for those machinists out there, can someone tell me what this is> http://imgur.com/gBWPi
23:52 rue_mohr help with which?
23:53 rue_mohr you need to rethread it?
23:53 rue_mohr or its not supposed to be tapered
23:53 parco idk what it is
23:53 parco or what goes on it
23:53 parco i recently picked up the drill, its a Clausing 16ST
23:53 rue_mohr looks like a chuck of some kind fits on it
23:54 rue_mohr not seen a taper with a theaded lock tho
23:54 rue_mohr katsmeow-afk, ?
23:55 katsmeow-afk there's no scale to tell how big it is
23:56 rue_mohr the upright is behind it, looks big
23:56 katsmeow-afk the drill press i have, the one that got off balance and bent the spindle, has a 3rd-party aftermarket threaded collar on it
23:56 parco here's another pic http://i54.photobucket.com/albums/g92/uselessdub/Shop/2011-07-09110130.jpg
23:57 rue_mohr if I take a AAA single battery holder, and fill it with mercury cells, how many volts will I get to?
23:57 rue_mohr 30?
23:57 katsmeow-afk yep, it's an oldetimey Sears drill rpess
23:57 parco do you know what kind of chuck would fit on that?
23:57 rue_mohr 1A @ 5V is ( )A at 30V
23:58 rue_mohr 160mA
23:58 rue_mohr hmmmm
23:58 katsmeow-afk oldetimey = "parts no longer available" , if you cannot find it on ebay or a yahoo group, i suggest you remove the spindle and have it ground to accept your favorite modern chuck
23:58 rue_mohr use it as a lathe to reshape its own spingle
23:58 rue_mohr d ^
23:59 katsmeow-afk to reshape it's down spingle?
23:59 rue_mohr you would do it, I'm ure of it
23:59 katsmeow-afk if it's olde, you'll wanna replace the spindle bearings anyhow
23:59 rue_mohr you would prolly bolt a grinder to the table or soemthing