#robotics Logs

May 31 2012

15:03 damiano i'm trying to develop a robot's arm
15:03 damiano it has to have a pincers as hand
15:04 damiano the hand have to bee free from clockwise and anticlockwise rotation
21:10 zhanx ok question the tiny85 is rate for -40c, does this mean it will operate just fine at extreme colds?
21:15 katsmeow-afk yeas
21:16 zhanx datasheet says -55c
21:16 Tom_itx keep it dry
21:17 zhanx modding my deep freeze this weekend
21:17 katsmeow-afk why?
21:18 zhanx i i think it runs to much
21:18 katsmeow-afk prolly does, no resedential fridge/freezer is adequately insulated
21:18 zhanx hence the modding
21:18 tsmeow-afk
21:19 zhanx plus i have to check the charge on it
21:19 katsmeow-afk what does the avr need to be inside the freezer for?
21:19 zhanx i want it in the lid with the rest of the controls
21:20 katsmeow-afk k, but if it gets that cold, won't your fingers stick to the controls?
21:20 katsmeow-afk if it's *in* the lid, it's displacing insulation too
21:20 zhanx control panel buttons are on the top
21:20 zhanx true
21:21 katsmeow-afk i'd mount it *on* the lid
21:21 katsmeow-afk after all, even if the avr is good for freaking cold, the rest of the stuff on the pcb prolly isn't
21:21 zhanx true but i will attempt this weekend to find otu
21:21 zhanx out*
21:21 tsmeow-afk
21:22 Tom_itx solder joints etc
21:22 zhanx i still have a couple of the tiny85 pcbs i had made left
21:22 katsmeow-afk capacitors, regulators, etc
21:22 katsmeow-afk batteries
21:22 zhanx triac
21:22 katsmeow-afk batteries especially lose power in cold
21:23 zhanx the deep freeze panel is 12vdc
21:23 katsmeow-afk if the 120vac goes out in a storm, you wanna know when the food is about to defrost
21:23 katsmeow-afk k
21:23 zhanx found that out tonight err 12vac
21:23 katsmeow-afk microwave just said dinner is ready, bbl
21:23 zhanx so i can make that dc easy to power the system
21:38 rue_bed you guys are gettin bombarded by mean weathe?
21:39 zhanx just wind here
21:39 zhanx it was wicked on the range today
21:39 zhanx 17 moa to the left to hit targets
21:39 rue_bed your the one of us who has to watch out what he's bombarded by
21:40 rue_bed try it with a paint ball
21:40 zhanx lol a paint must be frozen to travel that far
21:40 rue_bed moa = minutes of angle?
21:40 zhanx http://en.wikipedia.org/wiki/Minute_of_arc
21:41 rue_bed yea
21:41 zhanx same dif
21:41 e_bed th
21:41 zhanx at 500 meters i was curving the bullets on target
21:41 rue_bed 60 minutes to an hour
21:42 rue_bed x12
21:42 rue_bed is 120 * 6
21:42 rue_bed 1200 + 120
21:42 rue_bed 1320 minutes in a circle
21:43 rue_bed so a minute is less than a degree
21:43 zhanx not really
21:43 zhanx moa is 100 meters
21:43 zhanx for a scope
21:43 rue_bed oh its not hte same as a surverys minute
21:43 rue_bed srry
21:43 zhanx about 3 cm adjustment
21:44 zhanx scopes are a bit different yes
21:44 zhanx depending on scope though
21:44 rue_bed I have to get up
21:44 zhanx some are survey specs and they toss you off
21:44 zhanx but i am shooting an acog
21:45 rue_bed I'm ill, I'm sure of it
21:45 zhanx http://en.wikipedia.org/wiki/Advanced_Combat_Optical_Gunsight
21:45 zhanx they are fun
21:45 zhanx i have a 68 and an acog for my m4/203 combo i am assigned right now
21:46 rue_bed and hows the girlfriend
21:46 zhanx with a front loaded pvs14 night vision
21:46 zhanx good
21:46 zhanx she was laughing at me when i got home covered in mud from today
21:46 rue_bed ah you not locked in camp then
21:47 zhanx not it was a range competition today
21:47 rue_bed so are they going to keep you or kick you out?
21:47 zhanx hand down won it, keep me
21:47 zhanx i got promoted
21:47 rue_bed hot air rises?
21:47 zhanx something, my boss left and they promoted me
21:48 rue_bed ah
21:48 zhanx guess he is on to better things
21:48 rue_bed your just gonna stay around and let the seniority take you to the top
21:48 zhanx nope, i am gonna make it myself
21:48 rue_bed so your a troop leader leader then
21:48 zhanx did my range qual today to get back in it, and yes i am
21:49 rue_bed so now instead of breaking one troop, your gonna break a battalion
21:49 zhanx next month is my pt test and i plan to max that and i get a platoon if i do
21:49 zhanx battalion in two years
21:49 rue_bed wait I'm sure I said that wong
21:49 zhanx company i want next year
21:50 rue_bed in a platoon less than a battalion?
21:50 zhanx i need 8 more months as a plt sgt to get a 1sg (which is company and has 4 platoons in it)
21:50 zhanx after company is battalion
21:50 rue_bed you gonna take them out on some natural disaster releif stuff?
21:51 zhanx but since i schooled on the range today i am getting looked as PSD platoon sgt now
21:51 rue_bed where does platoon fit in?
21:51 zhanx company is made up of 4 platoons
21:51 rue_bed ah
21:51 zhanx not getting into company + and -
21:51 zhanx or squadrons
21:51 rue_bed easy, 3 is comany, 4 is a crowd
21:52 zhanx no
21:52 rue_bed :)
21:52 zhanx 4 is a company
21:52 zhanx 5 is a company +
21:52 rue_bed yes it is, we all learned that from tv
21:52 zhanx 3 is a company -
21:52 zhanx 17 squads is a squadron
21:52 zhanx :D
21:52 rue_bed 3 is company, 4 is a crowd
21:53 rue_bed dear god, how old AM I
21:53 zhanx but either way i want the recon platoon, not the psd platoon
21:53 zhanx 3 is company was on tv for me too
21:53 rue_bed ah
21:53 zhanx i am 35 after all
21:55 ace4016 jeez you're old
21:55 rue_bed hahaha
21:55 zhanx rue is like way way older
21:55 ace4016 but we already knew that :P
21:57 zhanx but he brings back old school
21:58 zhanx rue_bed: get out of bed work on the 12" bot now!
21:59 rue_mohr did you see the pipe mockup?
21:59 zhanx nope
21:59 rue_mohr your military there, hmm I dunno
21:59 zhanx whatever
21:59 rue_mohr http://eds.dyndns.org/~ircjunk/robots/sparrow1/p1040018.jpg ITS GONNA GET YOU!
22:00 rue_mohr http://eds.dyndns.org/~ircjunk/robots/sparrow1/p1040015.jpg no, it died
22:00 rue_mohr I'm sure your saw it now tho
22:00 zhanx that a jungle gym?
22:00 rue_mohr you agreed with me that its really not that big
22:00 zhanx its like a stick man without a head
22:00 zhanx :D
22:00 rue_mohr just a plastic mockup for size ref, also so I can work out the structure
22:00 zhanx k
22:01 zhanx i want to see the hydraulics
22:01 rue_mohr pnaumatics
22:02 zhanx hmmm
22:02 zhanx frame will store air?
22:02 rue_mohr http://eds.dyndns.org/~ircjunk/robots/sparrow1/p1030525-valvetest.jpg
22:02 rue_mohr no
22:02 zhanx why not
22:02 rue_mohr sealing it would be a pain
22:02 zhanx you have to weld it anyways
22:02 rue_mohr yes
22:02 zhanx so use the space
22:03 rue_mohr I dont know how I want to do the joints yet, hence the mockup
22:03 zhanx k
22:03 rue_mohr at 300psi, wouldn't hold much
22:03 zhanx still a bit more with tanks
22:03 zhanx every bit counts
22:04 rue_mohr it'll have some tanks
22:04 zhanx but why waste space
22:04 rue_mohr there will be less than 24 feet of 2" pipe in the frame
22:05 zhanx so like 2400 cuft of air max
22:05 rue_mohr http://www.youtube.com/watch?v=lTCACvgRZCY&list=FLPqhe-f22nx8XkLW-CysxQw&index=6&feature=plpp_video
22:05 rue_mohr I like the joints done on that, some of them
22:06 rue_mohr not all practical in real life, but well thought out
22:06 zhanx well i am thinking of hand winding some motors to start on that
22:07 zhanx i hate hand winding crap
22:07 ace4016 it's an animation rig and they're testing out the rig...some animation mistakes though >_>
22:07 zhanx true
22:07 ace4016 oh wait...robitics...not cgtalk
22:08 zhanx but still 80% possible
22:08 ace4016 it's pretty easy to do that stuff in art programs with constraints and such; they don't have to deal with real actuators and such :D
22:08 rue_mohr http://eds.dyndns.org/~ircjunk/robots/sparrow1/lg_puppet_master_locatornaming.jpg
22:09 zhanx a rue has the answer
22:12 rue_mohr http://eds.dyndns.org/~ircjunk/robots/sparrow1/dollar.png :)
22:45 katsmeow-afk http://www.youtube.com/watch?feature=endscreen&v=B0qYob_vSgo&NR=1 <<== copied from a Mars movie
22:46 SavageSimian i've got a robot arm (OWI 535) that i just hooked some optical encoding wheels up to. anybody got any tips on aligning the sensors?
22:49 rue_shop SavageSimian, hi
22:49 rue_shop yes
22:49 rue_shop do the encoders have an index?
22:49 rue_shop are you there?
22:50 SavageSimian yes. i'm here. sorry. tinkering... i don't know about indexes?
22:51 rue_shop so you have an arm with incremental enccoders
22:51 rue_shop !assist robots/arm4
22:51 tobbor Possibly http://eds.dyndns.org/~ircjunk/robots/arm4
22:51 rue_shop http://eds.dyndns.org/~ircjunk/robots/arm4/p1010986.jpg
22:51 rue_shop see the disk at the front bottom?
22:51 rue_shop just under the bottom spring
22:52 SavageSimian one next to the airpax motor?
22:52 SavageSimian no wait. i see it. at the bottom...
22:53 rue_shop no by the airpax
22:53 rue_shop see its a half disk?
22:53 rue_shop the transition from open to blocked is the zero point
22:53 SavageSimian ok
22:53 rue_shop when you start up you know what direction to go to get to zero
22:54 rue_shop absolute position sensors are nice for stuff like that
22:54 rue_shop http://eds.dyndns.org/~ircjunk/robots/arm5/p1030873.jpg
22:55 rue_shop even if its just potentiometers
22:55 SavageSimian yes. i'm not real concerned about tracking direction. i figure the microcontroller can do that but i plan to ink in something similar.
22:55 rue_shop yes, but you have to know what direction to go to get to the zero reference
22:55 rue_shop its better than just having a disk with one slot in it,
22:55 rue_shop with the disk, you wouldn't know what direction to go, just that your not at zero
22:56 SavageSimian there will be 2 zeros. one at each extreme of the range of motion...
22:56 rue_shop so you would have to go all the way one way, and then potentially back all the way the other
22:56 katsmeow-afk ignore the robot wearing human clothes in the top right of that pic
22:56 rue_shop SavageSimian, do you want the limits to be software or hardware based?
22:57 SavageSimian cool. personally, if it were my bot i'd probably put it in a tutu or something...
22:57 rue_shop SavageSimian, by zero, I mean the zero degrees position
22:58 rue_shop SavageSimian, wait, thats a servo based arm
22:58 rue_shop did you put encoders on the joints?
22:58 SavageSimian rue the range of motion will be hardcoded in EPROM. if the bot increments either direction and finds an endstop it will know where it is at...
22:59 rue_shop is that servo or just motors?
22:59 rue_shop an just motors it looks like
22:59 rue_shop huh
23:00 rue_shop well, you have the option of a limit switch if you want
23:00 SavageSimian just motors with encoders pulled from printers...
23:00 rue_shop it moves the motor back till it hits the limit switch, then knows that its at zero degrees, counts the encoder pulses from there
23:01 rue_shop stepper motors?
23:01 SavageSimian nope. plain ole dc.
23:01 rue_shop is your arm the owi535?
23:01 SavageSimian rue - y
23:01 rue_shop and you have printer encoders on it?
23:02 SavageSimian y
23:02 rue_shop cool
23:02 rue_shop do you want to use limit switches then?
23:02 SavageSimian heh. yea. if i can get em to work... :p
23:02 rue_shop just make it so that it hits the switch when it goes all the way [back] etc
23:02 rue_shop the encoders?
23:03 rue_shop are they from epson inkjets?
23:03 rue_shop 4 wires
23:03 rue_shop about 3" diamiter?
23:03 rue_shop 8cm?
23:04 SavageSimian don't know exactly which printers they came from. 4 motors, 4 different encoders...
23:04 SavageSimian my other hobby is tearing apart old printers... :p
23:05 rue_shop what does it say on it
23:06 rue_shop http://eds.dyndns.org/~ircjunk/tutorials/mech/gearbox/dscn7580.jpg
23:06 rue_shop :)
23:07 SavageSimian not much. one says 'applied image', 2 look like just a part number.
23:07 rue_shop tell me the numbers
23:08 SavageSimian heh. i'm guessing all that junk came out of an old clock? :p
23:08 rue_shop nope
23:09 SavageSimian i know. kidding.
23:09 rue_shop Q9863
23:09 rue_shop 9849
23:09 SavageSimian "QC1-4833"
23:10 rue_shop how the 33 eh?
23:10 SavageSimian "200 LPTI, GM25"
23:11 SavageSimian not sure what the other is. i'd have to disassemble the arm to get at it...
23:11 rue_shop 200 lines/inch
23:11 SavageSimian cool
23:11 SavageSimian what about the '33'?
23:12 rue_shop 9874, 9720 9988, 9863, I dont have any 33
23:12 rue_shop 9871
23:12 rue_shop so there are 4 wries off the little circuit board right?
23:13 rue_shop 9845
23:13 SavageSimian the other is "1800 CT, 200 LPI" 1800 marks @ 200 p/in?
23:13 rue_shop 200 lines/inch
23:14 rue_shop hahah
23:14 rue_shop THATS THE DISK
23:14 rue_shop dont give me the numebrs off the disk! :)
23:14 SavageSimian i don't know that i have the same sensors that came off the originals but all the sensors are the transistor type. 4 on the Q and 2 on the diode.
23:14 SavageSimian ok.
23:14 rue_shop ah, so you have the pinout
23:14 e_shop puts away the
23:15 rue_shop ok
23:15 SavageSimian no, but it's not too hard to figure out. they're all pretty much standard darlingtons right?
23:15 rue_shop all the ones I'm familiar with are logic level
23:15 rue_shop they are 4 pin sensors, with a 2 pin emitter
23:16 SavageSimian yea. put in a 5 or 3.3v and tap off the emitter...
23:16 rue_shop the sensors take 5V and gnd, and output 2 phases
23:16 rue_shop if the board had 4 wires, use that
23:16 rue_shop the resistor will be set for 5V operation
23:16 rue_shop ... did you take the sensor off the board?
23:17 SavageSimian the boards all have 6 wires.
23:17 SavageSimian hold on. let me see if i can find a schematic...
23:17 rue_shop wow, I think those were OLD printers
23:19 SavageSimian i'm guessing they are. most were between 99 cents and 3 bucks at the thrift store... :p
23:20 SavageSimian btw, imo the best printers to buy are the old ones. the motors are beefier and everything is built a little more solid...
23:26 SavageSimian ah. here are the sensors i'm using - http://www.societyofrobots.com/schematics_infraredemitdet.shtml
23:26 SavageSimian not the specific sensors. just the circuit.
23:28 rue_shop yea
23:29 rue_shop the old HP's put rotary encoders on the back of the motor
23:29 rue_shop THAT WAS AWESOME
23:29 rue_shop I tuck those away
23:29 SavageSimian if i can't get enough definition out of the sensor as is i'll probably hang a comparator off it and put a schmitt trigger on the front end...
23:29 rue_shop no those sensors prolly aren't anything like that
23:29 rue_shop even if they were
23:30 SavageSimian i've torn apart several HP's. never found the encoder on the back. guess i'll have to tear apart several more... :p
23:31 rue_shop ARG I cant find ANOTHER schematic
23:31 rue_shop look I have a really good schematic for phototransistors, give me a bit to find it
23:31 SavageSimian i've got a couple of hp's that need disassembling right now. i was putting it off because i'm gonna have to start throwing away those damn hex screws if i get any more of em...
23:33 rue_shop this cellery is tooo slow for searching back in a min
23:34 rue_mohr 1Ghz intel processors are hopeless for browsing the web
23:35 rue_mohr http://eds.dyndns.org/~ircjunk/circuits/linebot.jpg
23:35 rue_mohr there
23:35 rue_mohr that is a REALLY good circuit for phototransistors
23:37 rue_mohr SavageSimian, ?
23:37 SavageSimian cool. i'll give it a try.
23:38 rue_mohr gonan try and look up that sensor
23:38 rue_mohr 9833
23:38 SavageSimian sorry. i needed coffee. when my caffeine level gets dangerously low i go into crazy mode...
23:39 katsmeow-afk too much blood in your caffine stream?
23:39 SavageSimian exactly. they only use that stuff to dilute the caffeine anyway right?
23:39 tsmeow-afk
23:40 SavageSimian damn. don't think i have a 7486 in the junk box. :(
23:40 SavageSimian rue_bed: 4833
23:41 rue_mohr thats on the sensor right?
23:42 SavageSimian no. on the wheel.
23:42 rue_mohr the wheel dosn't matter
23:42 rue_mohr whats on the sensor
23:42 SavageSimian ok
23:42 Tom_itx i don't get why my main voltage is 50v and the centertap voltage is 50v
23:42 SavageSimian hold on...
23:42 katsmeow-afk on what?
23:43 Tom_itx i swear i measured 25v at the centertap once
23:43 Tom_itx on my psu
23:43 Tom_itx i added a cap to the centertap and it's 50v now
23:43 Tom_itx it's not supposed to be unless that's not a centertap
23:44 katsmeow-afk hold on a min, ro beeping
23:45 Tom_itx i'm gonna give up for tonight
23:45 SavageSimian half a dozen sensors. none a 9833. got a 9985
23:45 katsmeow-afk post a schematic
23:46 rue_mohr ugh thats the part number
23:46 katsmeow-afk you have full bridges on the outside wires, you need one diode on the ct to make 25v, the cap peak is 25x1.4 or 35v
23:47 SavageSimian do you want numbers stamped on the sensor or on the board?
23:47 rue_mohr is it Q 9985?
23:47 rue_mohr no the number on the sensor itself
23:47 rue_mohr printed on the end under the plastic bit that holds the disk in the right spot
23:48 Tom_itx one diode??
23:48 rue_mohr take apicture of the board on the robot and post it, I can work from there
23:49 SavageSimian don't know how to post
23:49 Tom_itx http://tom-itx.dyndns.org:81/~webpage/cnc/psu/psu4.jpg
23:49 katsmeow-afk think about it, the bridge is electrically grounding each of the otehr wires alternately, putting the ct at 1/2 volts above ground when the brige is conducting,, the one diode is only to be sure there's no reverse current flow
23:49 rue_mohr SavageSimian, take a picture, get it on your computer and I'll show ya ;)
23:49 Tom_itx there's the schematic save an added cap on the odd bridge
23:49 SavageSimian ok. hold on. i'll take pics of what i have.
23:50 katsmeow-afk that's a photo, not a schematic
23:50 Tom_itx :)
23:50 Tom_itx the cap is on the small black and red wire
23:50 Tom_itx the black goes to all the common grounds
23:50 Tom_itx on top
23:51 katsmeow-afk you want one --|>|--- from the ct to the cap , correct, rue?
23:51 Tom_itx i don't understand that
23:52 Tom_itx but meh
23:52 katsmeow-afk noted
23:52 katsmeow-afk try it
23:52 Tom_itx not tonight
23:52 Tom_itx i just picked up my mess
23:52 katsmeow-afk it's only solder, or alligator clips
23:52 Tom_itx and i'll have to round up a diode
23:52 Tom_itx 1A should be big enough
23:52 Tom_itx 1n4004?
23:52 Tom_itx i forget
23:52 Tom_itx 1004 maybe?
23:53 katsmeow-afk 1n4004 is good for an amp at best
23:53 Tom_itx that's enough
23:53 katsmeow-afk 1n5404 is good for 3 amps
23:53 Tom_itx i got some other big ones but i dunno what they are
23:55 Tom_itx schottky would be ok right?
23:55 katsmeow-afk yeas
23:55 katsmeow-afk if the voltage is high enough
23:56 Tom_itx i'll look tomorrow
23:56 Tom_itx i'm tired
23:57 Tom_itx most of the rewiring is done i think
23:58 katsmeow-afk think of it this way: if you were to use the gnd as the ct of a fullbridge psu, you'd have +25 and -25, right?
23:58 SavageSimian rue_mohr: i've got pics. what did you want me to do with em?
23:59 katsmeow-afk but you have the ct, and you ground one side of the dc, to get 50v,, the ct is still at 25-0-25
23:59 rue_mohr SavageSimian, go to www.photobucket.com
23:59 Tom_itx i just figured the ct to be the neutral leg and the other one the high one
23:59 katsmeow-afk so you have 0-25-50 , like i said, the diode is to make sure there's no current backflow, it's not needed unless there's a problem, and we don't need no steeking problems, so use a diode
23:59 Tom_itx going to the bridge