#robotics Logs

Mar 17 2017

#robotics Calendar

12:03 AM MrCurious: anyone order a beaglebone blue?
12:05 AM anniepoo_: nope
12:08 AM MrCurious: arrow.com has a special on it free shipping + free raspberrypi 3 https://www.arrow.com/
12:08 AM MrCurious: $80
12:08 AM MrCurious: board details… perfect for budding roboticist's https://beagleboard.org/blue
01:12 AM rue_house: zhanx, you didn't answer about the nema steppers
02:33 AM Jak_o_Shadows: Got the 3D printer kossel rod ends
02:33 AM Jak_o_Shadows: Just pressed them all together with the vice
02:33 AM Jak_o_Shadows: vise
03:01 AM Jak_o_Shadows: Through, now I have to buy M4 bolts
04:35 AM Jak_o_Shadows: rue! (and others) What's a good number of M4 bolts to get
04:35 AM Jak_o_Shadows: http://pasteall.org/pic/show.php?id=113631 one of those is what I'm considerin gnow
04:35 AM Jak_o_Shadows: But I really really don't know
07:47 AM deshipu: I accidentally a delta: https://cdn.hackaday.io/images/3830521489752366638.jpg
07:47 AM deshipu: old pcbs make a nice building material
08:08 AM veverak: nie :)
08:10 AM veverak: hmm
08:10 AM veverak: mine hand itches to start to write macros in C++
08:25 AM joga: deshipu, heh neat
08:57 AM rue_bed: Jak_o_Shadows, 100
08:58 AM veverak: so
08:58 AM rue_bed: Jak_o_Shadows, that knee, there is no mechanical advantage for it...
08:58 AM veverak: graph for movement of 3DOF leg, with 30 steps per joint
08:59 AM veverak: now takes around 47MB of memory
08:59 AM veverak: finally, there is all adata i need, but nah
08:59 AM * veverak wanted to fit it in cache originaly
08:59 AM rue_bed: 30^3
09:00 AM veverak: 30k nodes, each node has around 26 edges, each edge is 56 bytes big
09:00 AM veverak: maybe I can decrease the size a bit more
09:05 AM veverak: and I am "tad" close to write python script to parse C++ code to generate helpful functions
09:05 AM veverak: generaly because C++ lack of introspection
09:05 AM veverak: like serialization/deserialization, something to print memory layout of strucutres
09:34 AM pokmo: do servos usually draw current even holding still?
09:36 AM rue_house: yes
09:36 AM rue_house: unless there is no load
09:36 AM rue_house: and then they only draw just a tiny bit
09:37 AM rue_house: you can easily tell the difference in them driving the motor or not by the current
09:37 AM rue_house: and thats how you get force feedback
09:44 AM veverak: yup
09:45 AM * veverak waits for pcb to control servo that got this included
09:48 AM rue_house: its just a diode and pulse capture, I keep saying it and nobody will listen, you can also do it with a transistor BE junction
09:50 AM pokmo: right
09:52 AM rue_house: I'll add it to the servo101 page
09:52 AM rue_house: remind me in 9 hours
09:55 AM rue_house: maybe it should bea servo 102 course
09:56 AM deshipu: 404
09:56 AM deshipu: at the least
09:56 AM rue_house: you not have a link for the servo101?
09:59 AM rue_house: http://ruemohr.org/~ircjunk/tutorials/elex/hobbyservo/servo101.html
09:59 AM rue_house: http://ruemohr.org/~ircjunk/tutorials/elex/hobbyservo/servo101.html
09:59 AM rue_house: http://ruemohr.org/~ircjunk/tutorials/elex/hobbyservo/servo101.html
09:59 AM rue_house: http://ruemohr.org/~ircjunk/tutorials/elex/hobbyservo/servo101.html
09:59 AM rue_house: http://ruemohr.org/~ircjunk/tutorials/elex/hobbyservo/servo101.html
09:59 AM rue_house: http://ruemohr.org/~ircjunk/tutorials/elex/hobbyservo/servo101.html
09:59 AM rue_house: http://ruemohr.org/~ircjunk/tutorials/elex/hobbyservo/servo101.html
10:00 AM rue_house: http://ruemohr.org/~ircjunk/tutorials/elex/hobbyservo/servo101.html
10:00 AM rue_house: http://ruemohr.org/~ircjunk/tutorials/elex/hobbyservo/servo101.html
10:00 AM rue_house: http://ruemohr.org/~ircjunk/tutorials/elex/hobbyservo/servo101.html
10:00 AM rue_house: http://ruemohr.org/~ircjunk/tutorials/elex/hobbyservo/servo101.html
10:00 AM rue_house: http://ruemohr.org/~ircjunk/tutorials/elex/hobbyservo/servo101.html
10:00 AM rue_house: http://ruemohr.org/~ircjunk/tutorials/elex/hobbyservo/servo101.html
10:00 AM rue_house: http://ruemohr.org/~ircjunk/tutorials/elex/hobbyservo/servo101.html
10:00 AM rue_house: http://ruemohr.org/~ircjunk/tutorials/elex/hobbyservo/servo101.html
10:00 AM rue_house: http://ruemohr.org/~ircjunk/tutorials/elex/hobbyservo/servo101.html
10:02 AM rue_house: http://ruemohr.org/~ircjunk/tutorials/elex/hobbyservo/servo101.html
10:18 AM veverak: rue_house: you did not read my comment correctly
10:18 AM veverak: I need done thing
10:18 AM veverak: like "here is link to site where you can buy it | here is link to PCB source and design files"
10:57 AM veverak: so
10:57 AM veverak: little play with memory aligment, data types
10:57 AM veverak: and graph is now 24MB
10:58 AM veverak: -> done()
09:26 PM rue_house: well
09:26 PM rue_house: how many channels?
09:27 PM rue_house: veverak, and you folks only want 4 bit resolution on the positioning dont you?
09:27 PM rue_house: cause you want 10000 channels
09:29 PM rue_house: I bought a shaft coupler, 8mm to 3mm, and I remember that I was going to drill the 3mm out to what I wanted
09:29 PM rue_house: but I have no idea what I wanted it for
09:40 PM deshipu: isn't drilling a worthy goal on of itself?
10:27 PM pokmo: are hobby servos meant to be not very durable because they're designed for "hobby" purposes?
10:30 PM deshipu: no, because they're cheap
10:30 PM deshipu: however, "not very durable" varies greatly