#robotics Logs

Sep 07 2015

10:40 rue_bed just need a battery on the bot and I'm set
10:44 deshipu yay
10:44 deshipu do you plan to have an encoder too?
10:45 deshipu what are you using for wheels?
11:04 rue_bed 3d printed
11:04 rue_bed yes, prolly put an encoder on it
12:01 rue_house just a stick on the side dealie
12:01 rue_house basic tach
16:26 theBear rue_shop3, 6pin 74244 ...gnd 5v R S MISO MOSI, but i wanted the other side, tho i'll do it by eye in a minute, so don't worry
17:17 rue_school 6 pin?
17:17 rue_school oh, its pin
17:17 rue_school yea, 6 pin could be either of the two pinouts
17:41 rue_school oh damn I didn't take pics of hte little bot
18:13 theBear ponyprog stk200 pinout, howbout that...
18:13 theBear while we at it, don't spose you got a schem or something for your board, maybe err, babyboard mk2 or 3?
18:13 theBear some cute name like that
18:47 rue_school :)
18:47 rue_school atmega32?
18:49 rue_school http://ruemohr.org/~ircjunk/avr/babyboard_mk3/babyboard_III.html
18:51 rue_school I think i recommend upgrading to a 324? lots more pwm and pin change interrupts
18:54 rue_school today you can get arduino boards that have built on usb converters for less than that atmega32 chip costs
18:54 rue_school and some of them even have the isp header
19:20 rue_school _hanhart, ace4016 akaWolf Anniepoo Anniepoo_winders arty_knots bolt buzzykins CrazyEddy Crenn-NAS cylon512 de-vri-es deshipu dhtns eadthem Elleo ferdna hackkitten humerusj Hyratel jason_ joga JPaul JT-Shop jthornton jzk Kamondelious2 Kostenko_ kriskropd LeelooMinai Loshki mbrumlow MrCurious_ MrCurious_ msantana mulvane noodle Nutter orlock osssireesh peepsalot pinkmuffinere pythonsnake ralouf sherlock Shroo simcop2387 sphenxes01 T3rr0rByte
19:20 rue_school 13 TDog tumdedum wolfmanjm Zhyr
19:20 Hyratel !
19:20 wolfmanjm yea?
19:20 Hyratel I has no monies
19:20 Anniepoo_winders ?
19:20 ace4016 ?
19:21 LeelooMinai Way to highlight 50 people at once:p
19:21 ferdna rue_school, wtf?
19:21 wolfmanjm going to kick us all out for not saying anything?
19:21 ace4016 lol
19:21 rue_school I was thinking it
19:21 Anniepoo_winders wibbit wibbit eerk eerk, neena neena oi oik
19:22 wolfmanjm that is the most ridiculous thing I have seen BTW :)
19:22 rue_school how many people have an active project right now?
19:22 rue_school wolfmanjm, it keeps the channel alive for about another 6 months
19:22 LeelooMinai Only dead people don't have active projects...
19:22 Zhyr I do not at the moment.
19:22 ace4016 i do, though it's not (currently) a robotics one. though it might help me make parts later on down the line
19:22 wolfmanjm nah that is not true...
19:22 Zhyr If only because I'm about to restart school tomorrow.
19:22 niepoo_winders raises her
19:22 Zhyr And will be inudated with academic projects.
19:23 rue_school so, why is everyone hanging out here if never saying anytingm
19:23 ace4016 it looks like i might have to create my own burner
19:23 wolfmanjm we have 100 people lurking in smoothieware, not everyone needs to talk, but if they see somehtign useful they may chirp up
19:23 Anniepoo_winders Fiddling with a small humanoid, but recently started a startup and it, and everything else in my life, are on hold
19:23 rue_school cause you have to admit, the channels avitivity levels are pretty low, is the hope to catch something cool going on?
19:23 wolfmanjm lurkers
19:23 Zhyr If there is sudden activity, I may or may not be drawn.
19:23 LeelooMinai rue_school: Because typing /part takes too much effort nowadays:)
19:23 Anniepoo_winders 8cD startup involves machinery movin' bout with computer
19:24 rue_school yea, but we go up to 48 hours with nobody saying anything
19:24 e4016 pets LeelooM
19:24 wolfmanjm if I see a post I check it, if it is interesting or I have experience in the topic I will help
19:24 Anniepoo_winders I occasionally answer a question when it's something I can answer intelligently
19:24 LeelooMinai Hence it's so quiet
19:25 Anniepoo_winders mostly that's hobbyist struggling with physics
19:25 LeelooMinai Ok, that was brutal - sorry:)
19:25 wolfmanjm so? no big deal I have it on a tab in my client, if there is activity I see it change color and I check it out I don;t have to sit here all the time, I have 8 tabs open ie 8 channels I monitor
19:25 ace4016 lmao
19:25 wolfmanjm youi really want to kill this channel then keep booting people for no reason ;)
19:26 rue_school well, thats a dose of activity for the day anyhow
19:26 wolfmanjm it is not like the IRC gods kill off inactive channels
19:26 rue_school remember, we depend on YOU to report lurkers so they can be dealt with!
19:26 wolfmanjm I nominate rue_* as a lurker :)
19:26 LeelooMinai BUt 99% of freenode is lurkers...
19:26 Tom_itx is that bot finally gone?
19:27 Anniepoo_winders agreed- I'd suggest the best way to make the channel active is to go to the shop, start picking up robot pieces, and run back to computer every so often to report your progress
19:27 Anniepoo_winders 8cD
19:27 Loshki I admit it. I'm a lurker. Oops.
19:27 rue_school you cant report an op as a lurker, thats just silly
19:27 wolfmanjm FWIW my hexapod rocks :)
19:28 rue_school wolfmanjm, whats the latest photo update of it?
19:28 wolfmanjm and at some point I'll push all my code to github ;)
19:28 rue_school you said you got ik about right
19:28 LeelooMinai Anniepoo_winders: Right, because it always works on IRC. You go to the channel, show your project and ... "-- Meh, that's boring... -- I did it in kindergarten. -- O, time to unlurk and troll a noob!"
19:28 wolfmanjm https://flic.kr/p/vewvz1
19:28 Anniepoo_winders lol
19:28 wolfmanjm https://flic.kr/p/vhkcsD
19:29 wolfmanjm I have added a few more gaits, and it is now controlle dby a PS3 bluetooth controller
19:29 rue_school nobody who isn't building anything can validly critisize any work by anyone
19:29 wolfmanjm need to take a few more vids of the various gaits
19:29 Anniepoo_winders my robot just goes back and forth in XY, so not cool - on the posittive side it's got alaser that blows holes in things.
19:29 rue_school nice
19:30 rue_school the dog skin for it looks really convincing
19:30 LeelooMinai I hope it has a fire extinguiosher on the negative side:)
19:30 wolfmanjm FWIW I do spend more time building 3d printers and the firmware than the time I spend on the hexapod
19:30 Anniepoo_winders does the Tormach count?
19:31 Anniepoo_winders 8cD
19:31 rue_school did you have to hand create the hexagon pattern?
19:31 wolfmanjm it was a module in openscad
19:31 rue_school well, I'm glad I dont have to be the only one keeping the channel alive by building things all the time
19:32 rue_school who else is building what?
19:32 wolfmanjm so I just create a hexagon outline and union with the hexagon module
19:32 rue_school wolfmanjm, why did yo uchoose the circular config instead of the long body config?
19:32 wolfmanjm rue_school: I rad somewhere that it was more stable, my original one was rectangular
19:32 rue_school hmm
19:33 rue_school are those standard servos or serial robot servos?
19:33 wolfmanjm it complicates the S/W by about 10 extra lines of code :)
19:33 wolfmanjm they are MG90S
19:33 wolfmanjm barely enough torque at 6v to stand up, but with a special sequence I can get it to stand without help
19:34 wolfmanjm once walking it is fine
19:34 LeelooMinai I practically completed building a CNC, but then got sidetracked in a crazy way when I decided I want to map the table with a digital indicator and here I am - I built some FPGA boards for that and learned all HDLs there are, etc:)
19:34 ace4016 hrm...
19:34 wolfmanjm if i were to do it again I'd use bigger servos, or use mechanical advantage like stubby
19:35 elooMinai is a Master Yak Sh
19:36 niepoo_winders shaves LeelooM
19:36 rue_school wolfmanjm, what are you using to generate the servo pulses
19:36 rue_school 18 servos?
19:37 wolfmanjm a couple of 16 channel PWM boards from adafruit
19:37 rue_school what do they use to do it?
19:37 rue_school not a PIC is it?
19:38 wolfmanjm https://www.adafruit.com/products/815
19:38 wolfmanjm PCA9685
19:38 wolfmanjm also having two aloows be to psplit the load across two ubecs as one ubec does not seem to be able to handle the current
19:39 rue_school ugh
19:39 wolfmanjm even the 5A ubecs actually only handle about 2.5amps before shutting down
19:39 rue_school thats NOT true 12 bit
19:39 wolfmanjm I hate UBECS :)
19:39 rue_school my firmware prolly does better as far as resolution
19:39 wolfmanjm yea they work well enough for the 9G servos
19:40 wolfmanjm I tested the pulses on a logic analyzer and they do a reasonable job
19:41 wolfmanjm they can move at sub degrees resolution so any more resolution really wouldn't be of any advantage especially gven the lack of torque in my servos
19:41 wolfmanjm yea i could have used an arduino and S/W PWM
19:41 wolfmanjm but I am using an edison as the brains so I2C is a better communication option
19:43 rue_school my code does 24000 counts of real resolution
19:43 rue_school iirc
19:43 rue_school its rock stable, but yours will be too
19:43 wolfmanjm can it handle 18 servos :)
19:44 rue_school it does 8, properly
19:44 rue_school and it can be ganged up with other on the bos
19:44 wolfmanjm I get a lot of jitter but that is just crappy cheap chinese clone servos
19:44 rue_school bus
19:44 rue_school yes, the last few cheap servos I got jitter all on their own
19:44 rue_school some quite badly
19:46 rue_school I saw one article online on how to tune them down a bit, but it didn't match up with the servos I have
19:48 ace4016 any of you use non-R/C servos for servos?
19:48 e_school raises a robtic
19:49 ace4016 or are those the only things in the affordable range for most people?
19:49 ace4016 ah
19:49 e_school raises a robot gri
19:49 e_school is out of arms set up to r
19:49 rue_school my hexapod uses gearmotors and pots
19:50 ace4016 hrm
19:50 rue_school want the controller code?
19:50 ace4016 nay
19:50 rue_school mega32 runs 4 control loops
19:50 ace4016 gearmotor as in DC brushed motors?
19:50 rue_school serial control and analog feedback?
19:50 rue_school yea
19:50 ace4016 gotcha
19:52 ace4016 was thinking of messing with an SRM for a servo
19:52 ace4016 though that has nothing to do with the burner i'm designing/making/buying
19:52 ace4016 well...unless i can find a way to make a ceramic motor core :P
19:54 Anniepoo_winders sadly, ceramic magnets have high hysteresis (that being the point), you want low.
19:56 ace4016 wasn't looking at a magnet per se
19:56 ace4016 i wasn't sure if a ferromagnetic ceramic that wasn't a magnet could be made
19:57 eadthem rue_school finaly working on my mmo project
19:57 eadthem <rue_school> how many people have an active project right now?
19:58 ace4016 they'd be less conductive than silicon steel, though not as high magnetic permeability
19:58 rue_school well, if your interested in the code its around
19:58 rue_school so lets see
19:58 rue_school that adafruit board
19:59 rue_school 12 bits
19:59 orlock Eurgh
19:59 orlock i got a decent amount of sleep yay
19:59 Anniepoo_winders you certainly could make one - just don't cool it in a big magnetic field
19:59 orlock rue_school: that hot end mount plate i bought
19:59 rue_school servos have a max of 2ms every 20ms
19:59 orlock rue_school: if you remember? anyway - the slot for the neck is about .5mm too wide!
20:00 Anniepoo_winders the issue's the windings and insulation
20:00 rue_school 10%
20:00 rue_school 12bits is,
20:00 Anniepoo_winders fun fact - many electric motors work underwater
20:00 orlock Distilled water i assume?
20:00 rue_school 8 = 256 9 = 512 10 = 1024, 11 = 2048 12 = 4096
20:00 rue_school so, 10% of 4096
20:00 rue_school 409 counts
20:01 ace4016 Anniepoo_winders, aye, i figured if i cooled it outside the presence of a magnetic field, it wouldn't become a magnet
20:01 rue_school so between 8 and 9 bits
20:01 rue_school advertizing it as 12 bits is criminal
20:02 ace4016 though, i have no idea if the ceramic produced will be able to handle the forces an SRM will put out :P
20:03 Anniepoo_winders you could demagnetize one if you have a huge electromagnet and drove it with AC, then slowly turned down the current
20:03 Anniepoo_winders 8cD worked for ships in WWII
20:04 ace4016 hehe
20:06 ace4016 this burner design will be fun
21:01 mondelious w
21:01 ace4016 ahoy
23:10 sector_0 how accurate would a scara arm built from regular steppers be?
23:13 rue_school depends how its built
23:14 rue_school sector_0, it could have 100000:1 gearboxes and be really good, or it could have 20steps/rev and be really bad
23:14 rue_school then again, I suppose that wouldn't technically be an accuracy problem
23:15 sector_0 oops
23:15 sector_0 I forget to say NEMA17..
23:15 sector_0 I meant "regular NEMA17"
23:15 rue_school dosnt'' matter
23:15 rue_school did you want to connect it direct to the joint?
23:18 sector_0 haven't thought of concrete plans yet but I was thinking of a timing belt setup
23:27 rue_school well, stepper motors put out a lot of torqe as far as motors go, but they aren't geared
23:27 rue_school unless its a geared stepper