#robotics Logs

Nov 13 2015

01:54 Hyratel1 banana for scale https://dl.pushbulletusercontent.com/KdiGy1nBadEnyA4VP8d162JuUJOceWKB/20151113_010833.jpg
02:05 deshipu that's a cheap-ass banana
02:09 Hyratel1 it's not my Good Probe
02:12 deshipu that's what she said
03:00 anonnumberano https://www.youtube.com/watch?v=OcC_K8L52I4
03:00 anonnumberano epic fight
03:24 deshipu I wonder how well a computer simulator of such a robot would work as a game
03:27 anonnumberano Very well given the cult following young people have for Gundam and Gunpla (plastic models of Gundam).
03:27 anonnumberano and Japanese competitions like Robo-One
03:27 deshipu should be relatively easy
03:27 deshipu use a ready physics engine
03:28 anonnumberano The fact that's the robots are hard to make makes it hard to get into the field but if a game was made it would be much more accessible to kids.
03:29 anonnumberano Prolly best to make an phone app.
04:03 akem hello robots
04:04 akem roomba versus bender, round one: fight.
04:57 anonnumberano The Neato wins.
06:17 Keukpa where are people on here based? I'm UK located.
06:18 veverak well
06:18 veverak on 20.10.2015 my package left china airport
06:18 veverak and it didn't arrived in my country yet
06:18 veverak and can't find a thing about it in tracking systems
06:18 veverak I suppose I shall contact the seller
06:19 veverak Keukpa: Czech Republic
06:19 Keukpa veverak: cool! :)
06:20 Keukpa THe home of the word Robot :)
06:21 veverak !!! :D
06:21 verak passes beer to Ke
06:21 veverak :D
06:22 veverak nah
06:22 veverak aliexpress seller just extended protection by 20 days
06:22 veverak and said that it's in 'customs'
06:22 veverak well, I will trust him.
07:11 LiohAu what is the difference between a 2 channel and 3 channel encoder?
07:15 Tom_itx 3rd channel is index
07:15 Tom_itx A&B are quadrature
07:16 Tom_itx 3rd is one ppr
07:16 LiohAu "ppr" ?
07:16 Tom_itx pulse per rev
07:17 LiohAu why would I need to know the ppr ?
07:17 LiohAu isn't this "hardcoded" depending on the encoder ?
07:17 Tom_itx when orientation is important
07:18 LiohAu hm not sure to understand
07:18 Tom_itx https://en.wikipedia.org/wiki/Rotary_encoder
07:22 LiohAu it's the word "orientation" that I don't really understand in this context.
07:23 LiohAu an absolute encoder tells the initial state, and you have 2 channels that indicates how much you moved. So you already know the "orientation"
07:23 LiohAu unless the "orientation" word had another meaning in your sentence
07:24 LiohAu I really don't see the point of this 3rd channel :(
07:24 Tom_itx a device may need to start in the same place every time. the 3rd channel lets you do that
07:25 Tom_itx otherwise you're just counting A B pulses
07:25 LiohAu So the 3rd channel gives you the PPR, and from the A B and PPR, you know how many ticks you have to wait to obtain a given position ?
07:26 Tom_itx generally when the index pulse is given, the device will stop
07:26 Tom_itx ie: a spindle on a cnc for a tool change
07:26 LiohAu ah?
07:27 Tom_itx when the index pulse is received it knows it's in place and will stop there
07:27 Tom_itx later..
07:29 LiohAu well i'm not sure to understand everything, but based on what you say, a 2 channel encoder would be enough on the wheel of a robot, while a 3 channel may be required to build a kind of servo, right?
07:30 LiohAu (1st case only needs to know how much it moved against how much was request, 2nd case needs to know its position at any time)
07:31 LiohAu well actually my 2nd example is probably wrong as an absolute encoder may be needed to keep the position with power off
07:36 LiohAu well at least I know what data the 3rd channel provide, even if I still don't really see the point. Thanks Tom_itx :)
07:55 anonnumberanon heh
07:56 anonnumberanon my nrf24l01 modules are working and communicating
07:56 anonnumberanon heh
08:43 anonnumberanon okay, moving servo remotely now
09:08 rue_house are you using the arduino libary to move a servo?
09:29 anonnumberanon oh god
09:29 anonnumberanon the leg moved
09:30 anonnumberanon yeah rue_house
09:30 anonnumberanon and I'm ahead of schedule, now to make some controller with 17 servo outputs
09:36 anonnumberanon i wonder if atmega328 has 17 usable ports for such endeavor
09:49 anonnumberanon gonna need multiplexers I think
10:08 Snert there are many. you might need level shifting too.
10:31 anonnumberanon Snert ah thanks for the heads up. What does that do?
10:31 robopal leveling up your signals ie. from 5v to 3.3v or reverse
10:33 anonnumberanon what kind of wizardry?
10:36 Snert it converts from 5v logic to 3.3v logic. or vice versa.
10:36 anonnumberanon Cause I may need to run the multiplexers on 3.3?
10:37 Snert cause the arduino/controller might use 3.3v on it's pins instead of 5v.
10:38 Snert or even 1.8v if it's an edison.
11:29 anonnumberanon Snert turns out one or more demultiplexers is what i need as the core of my controller.
12:42 LiohAu Snert: still here?
12:44 LiohAu I'm trying to find DC motors, any brand to recommend ?
12:44 LiohAu something cheaper than portescap, maxon, faulhaber
12:44 LiohAu I found http://www.mfacomodrills.com but the price are so low that I may be missing something in their datasheet :P
12:45 robopal for what usage LiohAu, how large
12:46 LiohAu robopal: something with RPM > 5000, and torque > 50 mNm
12:46 LiohAu it's to drive the lead screw of the arm I'm working on
12:47 LiohAu 24v would be perfect, but less is fine too..
12:51 robopal 5000rpm ungeared?
12:51 LiohAu robopal: sure
12:52 robopal you have your own gearbox?
12:52 LiohAu I'll have to use belt/pulley to drive the lead screw, so i'll use it to reduce the RPM
12:53 LiohAu anyway I just plan to reduce to 1000RPM, so ratio will be around 1:5 <-> 1:10
12:53 LiohAu depends on the motor..
12:54 robopal hmmm sound like a printer motor would be best for this application
12:54 robopal rue* should know ;p
12:55 LiohAu robopal: no, I don't want a stepper
13:01 robopal how ridiculous are motor prices... we can make mobile phones with tons of different technologies in them as cheap as dirt but no, plain simple motors you must pay as much money as an iphone :-/
13:03 LiohAu yeah... If they could just try to make low prices, they would have a lot of products using them, and they would probably get more cash..
13:05 LiohAu robopal: found the motor I need, https://prototypes.haydonkerk.com/ecatalog/brush-dc-motors/en/brush-dc-motors-9237S011-R1-SP
13:05 LiohAu just not in my price range.
13:56 robotustra hi
14:13 robopal have you heard before the term "suicide motor"?
14:14 robopal https://www.youtube.com/watch?v=JpLA4SBm-A4
14:14 robotustra me?
14:15 robopal all*
14:16 robotustra and what the problem with it?
14:18 robotustra motor as a motor
14:19 robotustra what's new about robotics?
14:26 SpeedEvil robotustra: A motor with a field and a armature winding, that is connected in series, and unloaded, will wind up to a very, very high speed
14:26 robotustra you mean async motor?
14:27 robotustra that's the plan http://imgur.com/xZEKXIT
14:28 SpeedEvil A universal motor
14:29 robotustra yeah, but for robotics it's good to have big torque and low voltage motors
14:30 robotustra I need such motors now
14:30 robotustra ideally very sort, line less then 2 cm
14:30 robotustra big torque
14:31 robotustra diameter could be up to 60mm
14:33 LiohAu_ So I come back, and someone is looking for a motor too? :)
14:34 robotustra I'm looking for my harmonic drive
14:34 LiohAu_ robotustra: maybe your requirements are easier to satisfy than mine ?
14:34 robotustra small motor
14:34 robotustra I didn't saw such DC motor
14:34 LiohAu_ oh, harmonic drive, no, your requirements are harder to satisfy :d
14:34 robotustra I actualy already build one
14:35 robotustra harmonic-like gearbox
14:35 SpeedEvil robotustra: what are you wanting it for?
14:35 SpeedEvil As a general principle motor output scales with volume * internal RPM, for any given technology.
14:36 robotustra I know but I want something like outrunner but with simple controller
14:37 robotustra to have 2 wires - plus and minus
14:38 LiohAu_ but why do you need an harmonic drive?
14:38 robotustra apply DC voltage - turns one direction, swap - goes other direction
14:38 SpeedEvil robotustra: outrunner + ESC
14:39 robotustra I want to jerk voltage very fast
14:42 robotustra so this solution probably will not work
14:42 robotustra and I heve to use special outrunners with angle position feedback
14:44 SpeedEvil Define 'jerk voltage'
14:44 robotustra I will swap voltage and use PWM to supply it
14:44 robotustra swap voltage frequently
14:50 robotustra so I want this motor to work as usualDC collector motor
15:04 robotustra SpeedEvil: I'll use such gearboxes and I need a small DC motor do drive it https://www.youtube.com/watch?v=POSKD3lSD8E
15:07 SpeedEvil What sort of wattage do you want?
15:07 robotustra small, 10-20 watts
15:09 robotustra actually I want to place about 11 motors like this
15:10 robotustra so the total wattage should not be more than 100 W in peak
15:12 robotustra average is planned about 50W
15:22 robotustra bbl
15:28 LiohAu_ SpeedEvil: can I ask you a dummy question about torque
15:29 LiohAu_ ?
15:32 SpeedEvil Sure
15:32 LiohAu_ So, still working on my kind of scara arm. The Z translation of the shoulder system is almost ok (with a ball screw and a motor driving the screw throught a sync/toothed belt), and now I would like to determine the torque required to make the Z rotation.
15:33 SpeedEvil Watts = watts
15:33 SpeedEvil If it's force * distance, or force * radial distance
15:33 LiohAu_ but in my case the distance is really small, no?
15:34 LiohAu_ let's say I have a box with only the ball screw + motor of the Z translation inside. And this box is on a susan turntable, this turntable is driven by another motor
15:35 LiohAu_ what distance should I use? the box width?
15:35 LiohAu_ Or does it depends on the distance of the full arm ?
15:35 eedEvil is mostly asleep, so
15:37 LiohAu_ I'm gonna try to make a drawing
16:07 Hyratel1 banana for scale https://dl.pushbulletusercontent.com/KdiGy1nBadEnyA4VP8d162JuUJOceWKB/20151113_010833.jpg
16:32 ace4016 clever girl
17:02 LiohAu_ SpeedEvil: still there?
17:03 LiohAu_ anyway i'll ask on #mechanics it will be more appropriate :)
18:33 robotust1a evening
20:13 Snert How does a cop pull over a google self driving car when it is speeding?
20:14 robotust1a google selfdriving cars do not speed
20:15 Snert too fast, too slow, same difference.
20:15 Snert HOw does the cop let googlecar to pull over?
20:16 robotust1a police should have a button
20:17 veverak robotust1a: 'blow up button'
20:17 veverak :)
20:17 Snert well, it happened. So evidently there is already some sort of built in mechanism.
20:17 veverak Snert: aren't they still driving with human inside?
20:17 veverak he could do it...
20:18 Snert not all the time.
20:18 Snert http://www.cnn.com/2015/11/13/us/google-self-driving-car-pulled-over/index.html
20:21 veverak I see
20:22 robotust1a Snert: why do you care?
20:22 robotust1a do you have one car?
20:22 robotust1a such car?
20:22 Snert I don't! just find it interesting.
20:23 Snert it hints at cops having kill switches for the average citizen's things.
20:23 Snert like cops killing all cell phones during a time of unrest and rioting.
20:27 robotust1a it's called EMI
20:28 robotust1a but I thinc they will ask politely google to make a button for them
20:33 ace4016 Snert, i have a feeling they have microphones and cameras looking for things like that and try to park themselves off to the side in the case of passing emergency vehicles, or to stop if there's some persistence
20:38 Snert so it might be easy to pull over a googlecar with a speaker and some strobes.
20:38 Snert prolly specially coded light pulses or something the average guy doesn't know about.
20:40 Snert so what does EMI stand for, besides electromagnetic interference?
20:40 Snert after all, the authorities don't want their own cellstuff wiped out.
20:43 ace4016 they have radios that operate on another band
20:43 ace4016 just don't jam your own band :P
20:47 robotust1a I thought this channel is about robots
20:49 Snert thatz whachaget for thinkin
20:51 ace4016 well, we did talk about the google car, which is totally a robot
20:51 ace4016 and jamming is a concern for autonomous robots that use remote communication :P
20:51 robotust1a it's a robot done by google, not your robots
20:51 ace4016 pfft, i never saw the rule that we can only talk about our robots
20:53 robotust1a you are so seriously taking my words
20:54 Snert I might want a kill switch on the front of my arm for in case it runs amok.
21:03 robotust1a what problems it will solve&
21:03 robotust1a ?
21:16 robotust1a girls comming
21:16 robotust1a curious about robots?
21:16 ace4016 ?
21:16 robotust1a who is becca_KB1WRP
21:17 ace4016 ah; i turned joins/parts off.
21:17 ace4016 i think she's been in here before
21:17 ace4016 usually a lurker >_>
21:17 robotust1a not too much alive ppl in here
21:18 ace4016 happens
21:18 ace4016 robots are hard, and expensive :P
21:18 robotust1a hard?
21:19 robotust1a expensive? it depends
21:19 ace4016 well, i guess you can make toys
21:20 robotust1a the first robot I did costed me about 1500$
21:20 robotust1a and it has only 3 stepper motors
21:20 ace4016 bit on the pricey side :P
21:20 robotust1a it was a cnc
21:21 robotust1a it a cnc
21:21 robotust1a ti's
21:21 ace4016 ah
21:21 ace4016 bootstrapping your lab
21:21 ace4016 :D
21:22 ace4016 brings the cost of future projects down when you can do things yourself
21:22 robotust1a the second robot was made from kit
21:22 robotust1a and it is a 3d printer
21:23 robotust1a the price is about the same
21:23 robotust1a 1300$ about
21:23 robotust1a and now I'm building a robot of approximate cost of 5000$
21:24 robotust1a with about 100 motors
21:24 rue_house servos or motors?
21:25 robotust1a motors
21:25 robotust1a servos are not serious
21:26 rue_house are you talking hobby servos or any servos
21:26 robotust1a I'm talking about any servo
21:26 rue_house huh
21:26 robotust1a I don't like the SOUND
21:27 robotust1a they produce
21:27 robotust1a the eyes of my robot have 8 motors and they are almost silent
21:28 anonnumberanon the sound they make is what I like the best about them
21:28 robotust1a ha ha
21:29 ace4016 WHHRHRRRR
21:29 robotust1a listen to the sound https://www.youtube.com/watch?v=om_hhY21Tbg
21:31 anonnumberanon how many servos can you drive from atmega328 without demultiplexers? I want to do work before my demultiplexers arrive. Also I have several 328s.
21:32 rue_house an avr can run 8 servos with perfect timing
21:32 anonnumberanon i moved the leg of my robot a bit but each leg has 5 servos so I think I may be able to move two legs right now
21:32 anonnumberanon ah, I see
21:32 rue_house anymore than that and you WILL have timing glitches from overlapping interrupts
21:32 ace4016 if you want to do it via the PWM ports, like 4 or 8? it has the power for you to do one per output pin thoughif you really need to
21:33 robotust1a if you'll write the programm good you can drive as many as you have GPIOs
21:33 ace4016 you'll have to get clever to do so
21:33 ace4016 yea
21:33 rue_house I have code for a 328 that does serial access to 8 ports with shutdown and caching (iirc)
21:33 rue_house anymore than 8 and you WILL have timing glitches from overlapping interrupts
21:34 robotust1a are you sure?
21:34 robotust1a did you make debug with oscilloscope?
21:34 rue_house yes,
21:34 robotust1a show me the code
21:34 rue_house ok
21:34 anonnumberanon rue_house, what do interrupts have to do with this, just whenever you want to change the position?
21:34 rue_house I'll find the code
21:35 rue_house I think its posted but I'll check
21:35 robotust1a interrupts are not necessary to drive servos
21:36 rue_house look, I did it right, if you want to make a hack job out of it like the arduino does, be my guest
21:37 rue_house I only posted the mega32 version, pls stand by
21:37 robotust1a for my eyes- I have atmega 32u4 which drives 4 motors, read 4 analog sensors and 1 SPI communication with optical position sensor
21:38 robotust1a and they report to uart at 19200
21:38 rue_house I said my code drives 8 hobby servos with perfect timing
21:38 robotust1a have no trobles
21:38 rue_house thats what it does, NO glitches
21:38 robotust1a and you say that it's max amount?
21:39 anonnumberanon i need 10 servos right now
21:39 rue_house unless you overlap interrupts which will cause timing glitches
21:40 robotust1a anonnumberanon:
21:40 robotust1a I think you can drive 10 servos
21:40 anonnumberanon just want to make it stand until i recxeive demultiplexers
21:40 rue_house but my code also gives you 24000 counts of positioning, which nobody else can do
21:40 anonnumberanon im counting about 14 free ports
21:40 Jak_o_Shadows Use two uC's in the mean time
21:41 rue_house most of the systems they say are 16 bit barely come out to 7 when the overhead is done
21:41 robotust1a but I suggest you to take controller which can handle extra servos
21:41 anonnumberanon Jak_o_Shadows, means I'd have to synchronize them somehow.
21:41 anonnumberanon robotust1a, I'm designing my own controller.
21:41 robotust1a for what
21:42 rue_house :/ I didn't finish implemtning cached positions
21:42 Jak_o_Shadows Not if you just have some static powered on
21:42 anonnumberanon what do you mean?
21:42 anonnumberanon robotust1a,
21:42 robotust1a I mean describe your project
21:42 robotust1a if you can
21:42 anonnumberanon yeah ill give it a try
21:42 Jak_o_Shadows Think of it as an exercise in getting it to balance with less control than normal
21:43 anonnumberanon so I need 17 servos (17th not critical because it is the head) 5 per leg, 3 per arm
21:43 anonnumberanon end goal is to control it with a gamepad or joysticks
21:43 robotust1a humanoid like robot?
21:43 rue_house http://ruemohr.org/~ircjunk/robots/arm9/hobbydriver.tgz
21:43 rue_house thats the code, its for mega328
21:44 anonnumberanon must have recorded moves, and also react to joysticks to make it walk in whatever direction I want
21:44 anonnumberanon so buttons for recorded moves and the joysticks for walking (semi recorded walk gait im guessing)
21:45 rue_house 8 channels of perfect timing, with a 24000 count resolution, on a $3 atmega328 on a protocol that lets you use up to 32 servos on a serial port
21:45 anonnumberanon rue_house, how do you control your servos, what is your UI?
21:45 rue_house [255][servo #][MSB][LSB]
21:45 rue_house I could be persuaded to finish the extra features
21:46 rue_house servos 0-31 are direct write to servos
21:46 rue_house servos 31-63 are a position cache for servos 0-31
21:46 rue_house if you write to servo 255, it enguages the cached position to each servo at once
21:46 rue_house so no streaming delays
21:48 rue_house 14.some-odd bits of resolution
21:48 anonnumberanon rue_house, what do you use for your UI? have one yet?
21:48 rue_house you _will not_ find a REAL 14+ bits of timing on ANY other system
21:48 rue_house I dont have a gui, I have a library and a real time capture system
21:49 rue_house capture or puppet, whatever you want to call it
21:49 robotust1a what baud rate do you use?
21:49 rue_house did you look at the code?
21:49 robotust1a didn't find
21:49 anonnumberanon you move the servo by hand or in a controlled way? and then you record the positions in real time?
21:49 rue_house http://ruemohr.org/~ircjunk/robots/arm9/hobbydriver.tgz
21:49 rue_house http://ruemohr.org/~ircjunk/robots/arm9/hobbydriver.tgz
21:49 rue_house http://ruemohr.org/~ircjunk/robots/arm9/hobbydriver.tgz
21:49 rue_house http://ruemohr.org/~ircjunk/robots/arm9/hobbydriver.tgz
21:49 rue_house http://ruemohr.org/~ircjunk/robots/arm9/hobbydriver.tgz
21:49 rue_house http://ruemohr.org/~ircjunk/robots/arm9/hobbydriver.tgz
21:49 rue_house http://ruemohr.org/~ircjunk/robots/arm9/hobbydriver.tgz
21:49 rue_house http://ruemohr.org/~ircjunk/robots/arm9/hobbydriver.tgz
21:49 rue_house http://ruemohr.org/~ircjunk/robots/arm9/hobbydriver.tgz
21:49 rue_house did you find it yet?
21:49 robotust1a I'm looking through it
21:49 rue_house http://ruemohr.org/~ircjunk/robots/armcontroller/p1070088.jpg
21:50 robotust1a 9600?
21:50 rue_house I should update the images, I hadn't put the wires on yet!
21:50 rue_house yes 9600
21:50 rue_house and thats not too slow
21:51 rue_house in the time it takes to update every servo on a full bus, the servos havn't started a second update cycle yet
21:51 robotust1a you send the commands in the loop?
21:51 rue_house I send position updates as they are required, if the position dosn't change, I dont rewrite it
21:51 robotust1a one by one?
21:51 rue_house [255][servo #][MSB][LSB]
21:51 rue_house tahts the packet
21:52 robotust1a I got it
21:52 robotust1a it's ok
21:52 rue_house would you like an application example?
21:52 rue_house I have linux pc code I can post that takes positions from a file and streams them out
21:52 robotust1a no, I got what you do from code
21:53 rue_house yes, but this comes with all the spooler code
21:53 robotust1a all servos are holding position, each moment of time you change the ONLY servo
21:54 robotust1a one by one
21:54 rue_house in the time between servo pulses, the serial stream updates any servo positions that need to change for the next update pulse
21:54 rue_house its not 8 bit positioning, you need atlaest 2 bytes for the position
21:54 robotust1a I have to solve more difficult task - my robot arm will have about 30 motors
21:54 ace4016 so you don't have sub ms updates?
21:55 rue_house that code allows you to operate 32 servos on one serial port
21:55 rue_house :)
21:55 robotust1a and I need to send them the code to all of them at the same time
21:55 rue_house then get me to finish the caching
21:56 robotust1a 1 hand, athther hand and to all other motors
21:56 robotust1a I see your arm is more accurate for this time
21:57 rue_house my interpolator code can do 65536 axies at once
21:57 rue_house the interpolator code thats part of the example you said your not interested in
21:58 robotust1a I don't need 65535 axii, I heed only 100
21:58 robotust1a and they are not servos
21:58 rue_house your thinking small
21:58 rue_house the axies DO NOT HAVE TO BE PART OF THE SAME ROBOT
21:58 rue_house and they dont ahve to be hobby servos
21:59 robotust1a I DON'T HAVE MONEY FOR SUCH AMOUNT OF SERVOS :))))00
21:59 rue_house your spent $1500 on a machine with 3 motors
21:59 rue_house I spent $30 for each of 6 robot arms
21:59 robotust1a h hahahaaaaaa
21:59 rue_house which all have 6 axie
21:59 rue_house s
21:59 robotust1a I spent like 300$ for spidle
22:00 robotust1a and about 200$ for rails
22:00 robotust1a shit
22:00 rue_house I bought a drill chuck from the thriftstore for $2.50, new in package
22:00 robotust1a luck
22:00 rue_house new it would have been $15
22:00 robotust1a bit as aoon as I know you live in junk yard?
22:01 rue_house http://ruemohr.org/~ircjunk/robots/arm9/roboplayer.tgz
22:01 rue_house thats the code you dont want, dont download it
22:01 rue_house its got lots of good things you dont need
22:01 rue_house but its not written in oop
22:02 robotust1a int main( void ) {
22:02 robotust1a
22:02 robotust1a unsigned char pkt[2];
22:02 robotust1a unsigned char ptr;
22:02 robotust1a unsigned int temp;
22:02 robotust1a unsigned char data;
22:02 robotust1a it's your code
22:02 robotust1a here is the proof
22:03 robotust1a I write such code almost every day at work
22:03 robotust1a because I'm kinda programmer, embedded btw
22:03 rue_house the point isn't about it being simple or complex code, its code that WORKS
22:03 rue_house properly
22:03 robotust1a I'm glad
22:03 rue_house less the bits that dont cause I didn't write them ;)
22:04 robotust1a I'm telling that the task to contol 5 servos
22:05 rue_house sorry, I get pissed off when I see things like http://www.ebay.ca/itm/PCA9685-16-Channel-12-bit-PWM-Servo-motor-Driver-I2C-Module-For-Arduino-Robot-WC-/181849285199
22:05 rue_house cause, you DO NOT get even 8 bits from it
22:05 anonnumberanon yay just got my esr LCR meter in the mail
22:06 rue_house oo how low does it read?
22:06 rue_house 4 wire probes?
22:06 rue_house and the arduino libraries are a mockery of timing
22:07 anonnumberanon It's a device where you plug in your component: L, C, R diode, transistor.
22:07 anonnumberanon rue_house, we know
22:07 rue_house oh, one of the component testers, I got one, they are SWEET
22:08 anonnumberanon Yah. Mine is the one with buttons in the bottom right hand corner.
22:08 anonnumberanon Off and Test.
22:08 rue_house went thru all my transistors and found about 10 duds, and a fet things I didn't know I had like ujt's
22:08 rue_house mine uses a text screen, all the new ones seem to use graphics
22:08 anonnumberanon you saw the esr was bad on them?
22:10 rue_house some of the transistrs were just wires to blocks of resistance ;)
22:10 rue_house I got some of them used, so not a total surprise
22:10 robotust1a do you see strings? http://i.imgur.com/Rkbuxti.jpg
22:11 robotust1a I need a motor to each string
22:11 rue_house nice
22:11 robotust1a and I need to control them
22:11 rue_house is that yours?
22:11 robotust1a at 25Hz
22:11 robotust1a yes
22:11 rue_house 25 hz sucks
22:11 robotust1a it's enough
22:11 rue_house use dc motors and current control with position feedback
22:12 rue_house guitar wire?
22:12 robotust1a 30 DOF?
22:12 rue_house yea
22:12 robotust1a no, it's metal cord
22:12 robotust1a in plastic
22:12 rue_house personally, I'd use pneumatic muscles, but the controller would be big :)
22:12 rue_house I'd also only do 3 digits
22:12 robotust1a that's it
22:12 rue_house let me think on this
22:12 rue_house do you have motors?
22:13 robotust1a http://i.imgur.com/c201ilj.png
22:13 robotust1a I already know what I will use
22:13 robotust1a I'm just showing you what task I'm solving
22:13 rue_house why are there no teeth in the wrist to limit sideways slide?
22:13 robotust1a INTERESTING TASK :)
22:14 rue_house so, do you have motor drivers yet?
22:14 robotust1a do you have limiters in your hands?
22:14 rue_house how much force to you need on the lines when operating?
22:14 robotust1a no i didn't yet
22:14 rue_house yea, hands use ligaments
22:15 robotust1a the average force will be like 1-2 kg
22:15 rue_house ok
22:15 robotust1a max force
22:15 rue_house what speed of motion on the cable?
22:15 rue_house short throw I'm guessing
22:15 robotust1a 10 mm/c
22:15 rue_house maybe 5cm/sec?
22:15 rue_house k
22:16 robotust1a 5cm - is too fast
22:16 rue_house per sec?
22:16 Jak_o_Shadows who cares about AVERAGE force?
22:16 robotust1a yes
22:16 robotust1a I told max
22:16 rue_house wait, your range is 10mm?
22:16 robotust1a do you think your ligament do aster?
22:16 robotust1a do you think your ligament do afster?
22:17 robotust1a do you think your ligament do faster?
22:17 rue_house if your range is 10mm @5cm/sec on the cable your 10mm takes ... oh I went the wrong way
22:17 rue_house so, 3mm/sec?
22:17 robotust1a it's slof motion
22:17 robotust1a slow
22:18 robotust1a notmal speed is about 10 mm/s
22:18 rue_house 3 seconds for full retraction is pretty slow
22:18 rue_house you can move your finger between its limits in a hell lot less than 1 sec
22:18 robotust1a yes, but it's not me
22:18 robotust1a it's robot
22:18 rue_house a second is a really long, borring amount of time
22:18 robotust1a I don't want it to be faster than I
22:19 robotust1a 35 motors - one hand, 35 motors another
22:19 e_house thinks, 2kg 3mm
22:19 robotust1a 11 motors is the base
22:19 robotust1a 8 motors - eyes
22:20 rue_house linear conversion...
22:20 robotust1a + 20 DOF for just in case
22:20 rue_house say 32tpi...
22:20 rue_house f that... gimme metric
22:20 rue_house na, 32tpi
22:20 rue_house .79mm pitch..
22:21 robotust1a I don't know what are you calculating
22:21 rue_house 10mm
22:21 rue_house 12.6 threads
22:21 robotust1a I prefer to make a real and measure
22:21 rue_house call it 13 threads...
22:22 robotust1a I'll not use screws :)
22:22 rue_house in 3 seoncds
22:22 rue_house 260rpm
22:23 rue_house hmm, take that from, lets see, small motor, maybe 4000rpm
22:23 robotust1a 18000 rpms
22:23 robotust1a actually
22:23 rue_house under load tho?
22:23 rue_house lets say 8k under load
22:23 robotust1a ok
22:23 rue_house 31:1 gearbox
22:24 rue_house so, lets see
22:24 rue_house 2kg...
22:24 rue_house get my head around this bit now..
22:25 rue_house wedge...
22:25 rue_house ... go frictionless for now...
22:26 rue_house .. where is my black book...
22:26 rue_house ah there is another way
22:28 robotust1a ok, gonna sleep
22:28 robotust1a see u tomorros
22:28 robotust1a see u tomorrow
22:28 rue_house ah too bad
22:28 robotust1a what?
22:28 rue_house well I was gonna ballpark the motor size
22:29 robotust1a P = F*V
22:29 rue_house not that you havn't found one, but I'm interested
22:29 robotust1a f - is the force, V- is the speed
22:29 robotust1a P - is the power
22:29 rue_house no its T = Fnut/(2*Pi*p)*e
22:29 rue_house e being efficiency
22:29 Jak_o_Shadows +1 to rue
22:29 rue_house whcih I'll just set to 1 for now
22:30 rue_house p is pitch, but I'm not sure the units...
22:30 rue_house must be a ratio
22:31 robotust1a 10 mm/s = 0.01m/s , 2 kg is about 20N - so the power is 0.2 Watt
22:31 rue_house acgh, its accadenic so its in freaking newtons
22:31 robotust1a 2 W motor - can do 100 mm/s at 2 kg
22:31 Jak_o_Shadows Newtons are sane rue, please don't tell me you use lbf or lbm or slugs?
22:32 robotust1a he is so canadian
22:32 rue_house no I just prefer kg
22:32 robotust1a let him calculate
22:32 rue_house assuming WERE ON EARTH
22:32 robotust1a kg is not a force
22:32 rue_house I KNOW, AND IF YOU AREN'T ON EARTH PLEASE NOTE THE CALCULATION ERROR
22:32 robotust1a I'm canadian already, but not SO CANADIAN,
22:33 Jak_o_Shadows but then you stuff up the power calculations
22:33 robotust1a and I use Newtons )
22:33 robotust1a :)))))))
22:33 robotust1a I need to estimate the power of the hand - that's what I want
22:33 rue_house 2kg is 20N?
22:33 robotust1a yes
22:33 rue_house 9.81... yea
22:34 robotust1a so I go sleep
22:34 robotust1a good night
22:34 Jak_o_Shadows 9.81 is almost two significant digits too man
22:34 rue_house oh god it amounts to nothings
22:35 rue_house with a 31:1 gearbox they could be freaking pager motros and you would be fine
22:36 rue_house so pager motor -> 31:1 gearbox -> 8-32 threaded rod and your golden
22:36 Jak_o_Shadows you're moving bloody slow though
22:36 rue_house yea, well tahts the design
22:36 rue_house those little 3V toy motors would do too
22:37 rue_house either way, drivers are piffle
22:38 rue_house http://vegetronix.com/Products/AquaPlumb/
22:38 rue_house hahaha jus a few mo ago I made an avr do that
22:38 rue_house for my well
22:38 rue_house hahahaha
22:39 rue_house hmm, wonder how to print a 31:1 gearbox..
22:39 rue_house worm drive!
22:39 rue_house using threaded rod!
22:39 rue_house ;)
22:41 rue_house >> 10 mm/s = 0.01m/s , 2 kg is about 20N - so the power is 0.2 Watt<<
22:41 rue_house you realize he used acceleration, right?
22:42 rue_house cause otherwise it should have been joules...
22:43 rue_house its .2 joules of energy
22:45 rue_house over _3_ seconds
22:45 rue_house I wonder if he's a hobbyist or a student