#robotics Logs

Oct 24 2011

07:27 Tom_itx servo tray
07:31 KongfuPanda ok
07:32 KongfuPanda can I buy those somewhere in the UK for SG90 ? (micro-servos)
07:34 KongfuPanda I'm actually going to do some workshop training in a few months, so maybe I can try to make those parts in that workshop
07:38 parag0n KongfuPanda, where are you based? if you have a hackspace nearby, try emailing them
07:39 KongfuPanda in Oxford
07:39 KongfuPanda I think there is hackspace
07:39 KongfuPanda someone told me to join them a few months ago
07:39 parag0n are you making a hexapod? that seems to be the usual reason people fix two motors together
07:40 parag0n to do it, i've taken a couple of pieces of 12mm x 60mm x 20mm MDF, drilled some 3mm holes through, and bolted the servos to it
07:42 KongfuPanda parag0n, exactly, it's a home-made hexapod, it's working already, but not as good as I want it to: http://www.youtube.com/watch?v=4FxWpbLiw5g
07:43 KongfuPanda parag0n, I don't see how that would be possible with MDF
07:43 parag0n for minimum effort, try strapping a few cable ties round your existing motor blocks
07:43 KongfuPanda because my servos have 2-holes for bolts, and when they are at 90 degrees, those holes are like in completely different places and orientations
07:44 KongfuPanda oh yeah, I can try that
07:44 parag0n oh, i thought you were strapping them side to side
07:44 parag0n hrmm
07:47 KongfuPanda parag0n, I think I can actually just put some copper wire around them and tie it nicely
07:47 KongfuPanda I think it will be a good improvement
07:48 KongfuPanda or cable ties even better
07:48 KongfuPanda I need to buy some of those though
07:53 KongfuPanda also, I think my servos are struggling a little bit with the weight of my robot :( especially after I added 1 more Li-Ion battery to its weight
07:53 KongfuPanda I think I will make my legs a little bit shorter to reduce the torque
07:54 KongfuPanda any other quick and cheap suggestions to improve the performance?
07:56 KongfuPanda oh,yeah, I had two Li-Ion batteries before in parallel, but after like a week one of them stopped working, so I thought because of currently fluctuations I needed another battery to reduce the load on each. But after that I added 5 different capacitors in parallel (1 nF - 100 uF). Maybe with this improvement I don't need a third battery = extra weight?
07:56 KongfuPanda or would you suggest to keep the battery and look for improvements elsewhere?
08:00 parag0n in parallel? did you make sure both were charged to the same voltage before connecting them?
08:01 KongfuPanda I can't remember, I think so. I have a charger that just goes from yellow -> green when it's charged. So I think it was good. Now I also check that they have same volatge
08:02 KongfuPanda parag0n, in parallel, because the batteries are already at 7.4V, so I didn't need extra voltage, just more "juice " :D
08:03 KongfuPanda my servos are rated up to 7.2V, the batteries are of course charged to 8.32V (not 7.4V), but after going through electronics (I have same power for electronics and servos), servos get ~7.3V anyway . So I think it's fine
09:14 rue_mohr http://www.youtube.com/watch?v=Zqy4GPvATSE&feature=related <-- not bad
09:51 DammitCoetzee rue_mohr, that's pretty cool, looks like maybe a 100$ hexapod (minus the micro)
10:26 izua wow, the axon now runs for 74 GBP?
15:25 andrewvos Anyone here done any dev for the bioloid platform?
15:26 andrewvos I was wondering what language I would have to learn.
16:37 home ok
16:37 home I need some advice
16:37 home running a project with a team
16:55 Tom_itx andrewvos borg?
16:56 home ?
16:56 Tom_itx �
17:00 Tom_itx !seen zhanx
17:01 m_itx slaps to
17:01 Tom_itx !seen zhanx
17:01 tobbor zhanx was last seen in #robotics on Oct 23 20:13 2011
17:01 home !seen home
18:13 zhanx https://lh6.googleusercontent.com/-xiY8srAHSng/TqXuE_UZJlI/AAAAAAAACyM/aIFxGpXwpMc/s800/IMAG0649.jpg
18:31 andrewvos Tom_itx: What's Borg?
18:51 Tom_itx zhanx
18:52 Tom_itx http://tom-itx.dyndns.org:81/~webpage/emc/small_probe1.jpg
18:57 zhanx just a tad smaller
18:57 zhanx Tom_itx https://lh4.googleusercontent.com/-WGIrS5xVMVY/TqX0D1f7iQI/AAAAAAAACyc/ASCR0C8948E/s800/IMAG0651.jpg
18:59 Tom_itx makin good progress
19:04 Tom_itx http://tom-itx.dyndns.org:81/~webpage/emc/small_probe3.jpg
19:04 Tom_itx zhanx
19:05 Tom_itx see anything unusual about the one on the right?
19:06 zhanx small chuck
19:06 Tom_itx :)
19:06 Tom_itx http://tom-itx.dyndns.org:81/~webpage/emc/small_probe4.jpg
19:06 Tom_itx 1/4"
19:07 zhanx that for me?
19:07 Tom_itx mine are 3/8
19:07 zhanx cool
19:07 zhanx doing the crappy work right now
19:08 Tom_itx just finished turning the body for yours
19:08 Tom_itx figured i'd take some pics and sit a while
19:09 zhanx making collars for the threaded rod to the motors
19:09 zhanx https://lh6.googleusercontent.com/-ZnNUSPHnr0U/TqX7_-1Fb2I/AAAAAAAACys/zLIqrs-D_rc/s800/IMAG0654.jpg
19:09 zhanx one straight one off but will still work
19:09 Tom_itx i'm gonna get a short probe for mine
19:09 Tom_itx since the sherline is so short on z travel
19:09 Tom_itx threaded for M3
19:10 zhanx cool, tested my grub screw and it works good
19:10 Tom_itx rue would be proud you're using grub screws
19:10 zhanx just dont tell him
19:47 e_mohr snic
19:47 e_mohr whispers "you need two, 90 degrees ap
19:47 zhanx they are
19:48 rue_mohr two per end
19:48 zhanx one is just a bad drill job and only room for one
19:48 rue_mohr uh ho, I'm startin to fall asleep
19:49 rue_mohr urrr, ummm
19:49 rue_mohr so aggravated isn't much into the help he seems to ask for
19:49 rue_mohr I'm thinking maybe I should help by showing him how its done }:]
19:50 rue_mohr I realized that 6 linear actuators is NOTHING to me
19:51 rue_mohr how long is it safe to close my eyes for?
19:52 zhanx zero minutes
19:53 rue_mohr and how many seczzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz
19:54 zhanx hmmm
19:54 zhanx guessing i am recutting one side peice, i forgot motor mount holes
19:54 zhanx thats ok
19:54 zhanx I need to make it 25mm wider anyways
19:54 rue_mohr z, sis you see my pneumatic tests??
19:55 zhanx nope
19:55 rue_mohr well damnit man
19:55 zhanx waiting
19:55 rue_mohr http://eds.dyndns.org/~ircjunk/robots/sparrow1/p1030525-valvetest.jpg
19:55 zhanx https://lh5.googleusercontent.com/-RSkmbNFuKlE/TqYGwxJXROI/AAAAAAAACy8/Tn1qdNTaTJE/s800/IMAG0656.jpg
19:56 rue_mohr http://www.youtube.com/watch?v=_JPpA1llSm4
19:56 zhanx wish i had yoru space
19:56 zhanx your*
19:56 rue_mohr http://www.youtube.com/watch?v=A-WgzH-UZgM
19:56 rue_mohr I keep telling you guys not todo that or they will bind....
19:57 zhanx https://lh5.googleusercontent.com/-qGiBK-RISkI/TqYHXz4fT5I/AAAAAAAACzE/sUlRHdUN9kM/s800/IMAG0657.jpg
19:57 rue_mohr z, I think you need some heavier sliders?
19:57 rue_mohr oh no, its a pcb mill?
19:57 zhanx dual linear bearings?
19:57 zhanx yep
19:57 e_mohr shakes
19:57 Tom_itx rue_mohr
19:57 Tom_itx you see his probe?
19:57 rue_mohr why do people insist on trying to mill pcb?
19:57 Tom_itx beats me
19:57 rue_mohr Tom_itx, I saw the one you finished yesterday
19:57 zhanx cause rue, you know i can't have the chemicals here
19:58 Tom_itx http://tom-itx.dyndns.org:81/~webpage/emc/small_probe4.jpg
19:58 rue_mohr thats better
19:58 zhanx least i have a good reason
19:58 Tom_itx the spare has a 1/4" shank
19:58 rue_mohr zhanx, well, you dont need the heavy sliders, thats for sure
19:59 zhanx true
19:59 rue_mohr whats the allthread pitch?
19:59 rue_mohr you could go really small
19:59 zhanx 1/4 20
19:59 rue_mohr 1/4-20?"
19:59 rue_mohr mmm
20:00 rue_mohr 20tpi makes the numbers nice
20:00 zhanx allowed me to use the nlyon bushing to the motor with grub screws
20:00 rue_mohr mmm
20:00 rue_mohr zhanx, what do you think of the vids?
20:01 rue_mohr the background noise is the valves pulsing
20:01 rue_mohr so you can see how find the movement per pulse it
20:01 Tom_itx i wanna see a balloon pop
20:01 zhanx what is the pull on that?
20:01 rue_mohr pretty strong
20:01 zhanx i just see a rusty spring
20:01 zhanx i want real numbers
20:01 rue_mohr prolly about 5 lbs for that one
20:01 rue_mohr no it must be moce
20:02 zhanx not bad
20:02 rue_mohr cause a person (such as myself) can hardly hold it apart
20:02 rue_mohr I'll get the position servo working and give you numbers
20:05 rue_mohr the avr code is neat, its an adjustable on/off pulse genorator with about a 1.2ms resolution
20:05 rue_mohr uses a keybaord lcd and menu
20:06 zhanx you had fun making it
20:07 rue_mohr yea, been a while since an avr project
20:09 rue_mohr now I need to code a servo loop controller for it
20:10 rue_mohr http://webbot.org.uk/iPoint/30.page
20:10 rue_mohr thats an interesting library, quite new it seems
20:10 rue_mohr docs in it are dated the 11th of oct 2011
20:10 rue_mohr they have a pid loop control fn
20:10 duckinator huh, guess it's time for a new hard drive :|
20:10 rue_mohr but they dont say how to tune it :)
20:11 rue_mohr duckinator, clunk of death?
20:11 duckinator no, ATA errors up the wazoo
20:11 duckinator and bus errors
20:11 duckinator not sure if the bus errors are related, but pretty sure the drive's just about dead
20:17 zhanx https://lh4.googleusercontent.com/-vF8XyYP9NHA/TqYMHkIzX_I/AAAAAAAACzM/BOb4sIUX54U/s800/IMAG0658.jpg
20:17 zhanx think i might trim the last axis and call it good for the night
20:19 Tom_itx ok, out to make parts
20:20 rue_mohr zhanx, did you remmeber to mak ethe table twice as long as the smallest board you want to do?
20:20 zhanx yes
21:29 rue_mohr cd /files/programming/c/
21:29 rue_mohr mm
21:29 rue_mohr try again rue...
21:31 Tom_L easier to make 2 at once than one at a time
21:31 rue_mohr yup
21:32 rue_mohr same with hexapod legs
21:34 rue_mohr http://eds.dyndns.org/~ircjunk/images/canuhearme.jpg
21:34 rue_mohr its too bad you cant see the phone closer up
21:34 rue_mohr the bottom left button is "EXPLODE"
21:35 rue_mohr 2 up is "Random interrigation"
21:35 rue_mohr the big red one is "PANIC"
21:55 Tom_shop ok, i'm thinkin this is a good place to stop
21:56 rue_mohr you been stopped here for a long time, you just decided?
21:57 Tom_shop i'll finish the guts of the 2nd one tomorrow
21:57 rue_mohr ah
22:05 m_itx looks for a bunch of 4-40 grub sc
22:25 e_mohr cuts the heads off some screws, grinds a slot in the end with a dremel, uses a black marker to colour them, and hides them in various places for Tom_itx to fin
22:25 Tom_itx it's ok. i found some
22:26 Tom_itx a bit too long, but that'll give z something to do
22:26 rue_mohr huh, imagine that...
22:26 rue_mohr just lying around eh?
22:26 rue_mohr places you swear you already looked?
22:26 Tom_itx i have a plastic case full of hex stuff
22:26 rue_mohr mhm
22:27 rue_mohr lets see...
22:27 rue_mohr hex wrench....
22:27 rue_mohr hexapod...
22:27 rue_mohr bolts...
22:27 m_itx puts a hex on
22:27 rue_mohr love hex..
22:28 rue_mohr yea, you got alot of hex stuff in here
22:30 rue_mohr there's even some hexdecimal numbers in there...
22:30 Tom_itx zhanx
22:31 Tom_itx no rue, those are octal twins
22:31 Tom_itx zhanx_laptop
22:32 zhanx_laptop i guess i only needed a nap
22:32 Tom_itx zhanx the side adjusting 4-40 grub screws i have are too long so you will have to find some
22:33 zhanx_laptop k
22:33 Tom_itx about 1/8-1/4" long
22:34 Tom_itx all done but the probe tip thing
22:34 zhanx_laptop coolness
22:34 rue_mohr zhanx, can prolly just go to the stock room for saphires to use for the tip
22:34 zhanx_laptop lol
22:35 rue_mohr 'report stock adjustment, saphire dropped, could not be located'
22:35 rue_mohr then again, I'm sure a stockroom in the places he works are SPOTTLESS
22:36 rue_mohr even when I clean my shop, stuff falls into boxes filled with things that make recovery NOT WORTH IT
22:36 rue_mohr definitly not unloading a 300lb box of transformers to recover a 0804 1K resistor
22:37 rue_mohr but yaknow, good point maybe that box should be under the soldering station area
22:37 rue_mohr shouldn't
22:38 zhanx_laptop i would think not
22:41 rue_mohr zhanx, your familiar with the existance of flooded NiCd storage batteries?
22:41 rue_mohr 1000Ah?
22:41 rue_mohr ~
22:42 zhanx_laptop nope sorry
22:42 Tom_itx zhanx you wanna solder the wire to the ballbearings on yours?
22:42 rue_mohr ok how about just LARGE NiCd bats? almost all the Pb procedure stuffs I'v seen have provisions for also maintaining NiCd arrays
22:43 Tom_itx i wouldn't wanna deprive you of anything here...
22:43 zhanx_laptop Tom_itx, too easy
22:43 eadthem rue whats the name of that c programming room?
22:44 rue_mohr ##cprog
22:44 rue_mohr are you gonna bring it to life for me?
22:44 rue_mohr damn tom, almost had 3 people for a sec
22:45 rue_mohr that would be the 3 month high!
22:45 Tom_itx heh
22:45 rue_mohr oh oh oh I got 3!
22:45 home programming is a bitch.
22:45 home urgh
22:46 Tom_itx programming is eays
22:46 Tom_itx easy
22:46 rue_mohr you just have to see past the language, into the machine, and tell it what you want it to do.
22:47 rue_mohr ... the more languages you 'know' the easier that gets
22:47 Tom_itx keeping track of the syntax is a bugger
22:47 rue_mohr yea
22:48 Tom_itx and whether to indent or not
22:48 rue_mohr if I stray out of C I have to keep looking at examples to remember how to do things like write for loops :)
23:00 QWERT Can somebody help me out with FIRST robotics?
23:00 rue_mohr not if you dont ask us a question
23:01 rue_mohr sorry, its a requirement
23:01 QWERT ok
23:02 QWERT Which would be the most optimal programming language to use in FIRST robotics?
23:04 QWERT ?
23:04 rue_mohr C
23:04 rue_mohr its high level without high overhead
23:06 QWERT why not c++
23:06 rue_mohr c++ obscures the execution of you code, cause its execution path is execution path dependant, it makes debugging a nightmare
23:07 rue_mohr and it encurrs more overhead that just isn't neccissary
23:08 QWERT http://www.youtube.com/watch?v=KlPC3O1DVcg&feature=related
23:08 rue_mohr c++ is practical for acedemic programs, not for real world stuff.
23:08 QWERT what about LISP java and python?
23:08 rue_mohr all have tonnes of overhead
23:09 rue_mohr meaning you need POWERFULL processors to get anything done.
23:09 rue_mohr java is the worst
23:09 rue_mohr lisp is actually lower level than C...
23:09 QWERT why is "java the worst"?
23:09 rue_mohr but lisp is an evil language I woulnd't suggest to anyone
23:10 QWERT and what about ASM
23:10 rue_mohr because it consumes the most memory and processor resources for the least return
23:10 rue_mohr asm is fine, but you spend all your time writing code and no time making a program to do what you want done.
23:11 QWERT so c
23:11 rue_mohr no
23:11 QWERT ?
23:11 rue_mohr show me C code for adding 34+6 and storing it in a variable
23:12 QWERT im guessing
23:12 rue_mohr thats ok
23:12 QWERT int a,b
23:12 QWERT a=34
23:12 QWERT b=6
23:12 QWERT c=a+b
23:12 QWERT retrn,0?
23:12 rue_mohr fair enough
23:12 rue_mohr now show me assembler code for the same
23:13 QWERT my bad
23:13 QWERT int abc
23:13 rue_mohr you were close enough
23:13 QWERT no fucking clue...
23:13 rue_mohr ldi a, #34
23:14 rue_mohr ldi b, #6
23:14 rue_mohr add b
23:14 QWERT Thats it/
23:14 rue_mohr st a, #variable
23:14 rue_mohr a fair enough awnswer to the C question would have been
23:15 rue_mohr int C = 34+6;
23:15 QWERT That's inhuman to comprehend
23:15 rue_mohr now, want to see what you have to do to write 24.2+4.8 in asm?
23:15 rue_mohr it'll take about 69 lines if I'm carefull
23:16 QWERT ldi a, # 24.2
23:16 rue_mohr no
23:16 QWERT :(
23:16 rue_mohr you have to work out the floating point number in hexdecimal
23:16 QWERT well I thik I will start with c
23:16 m_itx wanders off into a cloudy mist never to be heard
23:16 QWERT just to be safe and prevent massive headaches
23:17 rue_mohr Tom_itx, LOOK OUT FOR THE WALL!
23:17 rue_mohr QWERT, I'll help you with any C question you can ask
23:17 ERT grabs Tom_itx quickly placing him gently in his poc
23:17 QWERT well I have none atm
23:17 QWERT jut do you know where i can get tuts
23:17 QWERT and learn the concept of it
23:18 rue_mohr I'll teach ya
23:18 rue_mohr running windows or linux?
23:18 QWERT mac/ windows
23:18 QWERT i can switch
23:18 QWERT i HATE MAC
23:18 QWERT caps
23:18 Tom_itx doesn't matter. c is c
23:19 QWERT well i prefer to use windows
23:19 QWERT one sec
23:19 QWERT well i have to sleep will you be on tomrrow?
23:19 rue_mohr yea, but the coding environment changes
23:19 QWERT tomorrow
23:19 QWERT what do you mean
23:19 rue_mohr oh sleep, right
23:19 rue_mohr sure
23:19 QWERT kk cya
23:19 QWERT and thansk for the help
23:20 QWERT thanks
23:20 rue_mohr the program you use to code C is different depending on what os you run
23:20 Tom_itx what �C does FIRST use?
23:20 rue_mohr no worries, I have embedded spelling and context correction
23:20 QWERT I have a windows but im sending it for diagnosis becasue it has a over heating problem
23:20 QWERT atm im using my mac
23:20 rue_mohr C spot run :)
23:20 rue_mohr we can start with your mac then
23:21 QWERT ok tomorrow
23:21 QWERT bye
23:21 rue_mohr bye
23:21 ERT releases Tom_itx into the
23:21 Tom_itx bye bye
23:23 rue_mohr hmm 24V 8Ah NiCd for $224
23:25 rue_mohr they dont tell me weight
23:33 rue_mohr Diesel trains use NiCd batteriest!!?!?!?!
23:33 rue_mohr damnit!
23:35 rue_mohr http://www.saftbatteries.com/Produit_STM___High_energy_module_for_traction_293_44/Language/en-US/Default.aspx
23:35 rue_mohr I THINK I FOUND THE BATTERIES I WANT TO USE IN MY TRUCK CONVERSION!
23:37 rue_mohr 6V, 100Ah, 13Kg
23:39 rue_mohr http://www.saftbatteries.com/doc/Documents/stationary/Cube782/NHE_pdt_en_0905.8ad292d8-3835-4fc5-b284-2d8b467eefce.pdf
23:39 e_mohr cries "I WA
23:40 rue_mohr 12V, 100Ah, 18.6Kg
23:41 rue_mohr zhanx, top of your head guess, how much does the 95Hp engine in my pickup weigh?
23:41 rue_mohr how much does a 80L gas tank full weigh?
23:42 rue_mohr I'm gonna say a full radiator weighs 20lbs
23:42 rue_mohr 9kg, thats almost half a battery! :)
23:43 rue_mohr I'm gonna say all the exhaust system weights another 20lbs, thats a battery right there
23:43 rue_mohr now I just need to find wieght for about 9 more
23:45 rue_mohr http://www.saftbatteries.com/Produit_Nickel_capacitor_SNC_455_298/Language/en-US/Default.aspx#DL2 <-- wuff, a CRANKING CAPACITOR
23:55 rue_mohr http://www.divms.uiowa.edu/~jones/step/index.html