#robotics Logs

Mar 22 2018

01:35 AM Jak_o_Shadows: rue, I got a 70MHz scope for $300 - and that's AIUD as well
01:38 AM Jak_o_Shadows: theBear, make your links links mate
01:50 AM Jak_o_Shadows: Also, i totally agree, I can't wait for cyborgs
02:28 AM aep is now known as Guest47242
03:00 AM theBear: whaddyamooiin ? you some wacky olde timey folk that likes a protocol in a proper err, unc? style address, and expects not typing www. infront of a website name to not find a website ? <grin> i been dabbling with this wacky new browser i stumbled on in hurry-not-really-desperation... it does a few odd things, it's called vivaldi, and it's surprisingly functional and in many ways different/above-avg for something i never even heard a mention of
03:03 AM theBear: then agian, i worked out how i broke my ffox earlier, so i probly slip back to that and my 10 odd sessions and many hundreds of not-properly-dealt-with/filed/closed/bookmarked/saved tabs across an unusually high number of windows <grin> i'm hoping i fell aslepp on the keyboard while in the 3d settings thinger, cos otherwise the liquor IS finally making me dangerously not-average-or-higher-intelligence-and-presence-of-mind finally, which is kinda the
03:03 AM theBear: long-term goal, try to get dopey and happy like those lucky fools i see out in the public places, BUT if so, is dangerously uninhibited in the random changing settings i KNOW i don't want set that way, just kinda going click-happy, like those normal people we fix computers for ... "something popped up so i just clicked in the affirmative to make it dissappear as quickly as possible ! what's wrong with that ?"
04:43 AM Jak_o_Shadows: hmm, that tab groups in vivaldi is nice
04:43 AM Jak_o_Shadows: and I always need another web rbowser installed
11:24 AM Snert__ is now known as Snert_
07:02 PM rue_: 8 packages from china~
07:28 PM logicmoo is now known as dmilez_
07:29 PM dmilez_ is now known as dmiles[m]
08:19 PM Rez is now known as LoRez
10:17 PM z64556 is now known as z64555
11:11 PM z64555: anybody have some good references for solving kinematic chains? I feel like this is highschool level/college years 1/2 problem
11:11 PM z64555: but unable to find a book that covers it in detail
11:12 PM rue_: for the hexapod?
11:12 PM z64555: yes
11:12 PM rue_: its a series of translations and rotations, just work it out
11:12 PM rue_: from the tip of the leg to the body
11:12 PM rue_: what is the length of the first segment?
11:13 PM rue_: -timeout-
11:13 PM z64555: Honestly have no idea, which is part of the reason why I'm looking for general solutions
11:15 PM rue_: translation, rotation, translation, rotation...
11:15 PM rue_: you have to have a design before you can do it
11:16 PM rue_: otherwise you might as well just use the matrix [A, B, C, D; E, F, G, H; I, J, K, L; M, N, O, P ]
11:17 PM rue_: where everything is a complex number.
11:17 PM rue_: :)
11:17 PM z64555: like a Jacobian matrix?
11:19 PM rue_: a maxtrix where every value is an unknown value
11:19 PM rue_: one for each point you want to solve for
11:19 PM rue_: each with different variables
11:19 PM rue_: a hexapod right?
11:19 PM z64555: ah, that matrix
11:19 PM z64555: yes
11:20 PM rue_: so, a total of 25 matrixies with completely unknown values
11:20 PM rue_: DESIGN THE ROBOT FIRST
11:21 PM rue_: its like asking how to calculate how much a bridge can hold, generically, with no bridge defined
11:28 PM orlock: rue: Did i show you the stepper/nano carrier i found on ali?
11:28 PM rue_: ? I dont think so
11:28 PM rue_: is it 3d printable?
11:29 PM orlock: https://www.aliexpress.com/item/3D-Printer-CNC-V4-engraving-machine-A4988-Reprap-Stepper-Drivers-Nano-3-0-with-USB/32809594653.html
11:29 PM rue_: oh
11:29 PM rue_: hmm $11
11:29 PM rue_: let me think
11:30 PM rue_: the nano is worth about $4
11:30 PM rue_: the drivers are worth about $2.50 ea
11:30 PM rue_: 7.50 +4
11:30 PM rue_: 11.50
11:30 PM rue_: hmm, ok, its an ok price
11:31 PM orlock: i was looking for something more like https://www.aliexpress.com/item/DRV8825-A4988-3D-Printer-42-Stepper-Motor-Driver-Control-Expansion-Board-Shield-Module-For-Arduino-UNO/32838869245.html
11:31 PM rue_: I wonder if its config fits grbl
11:31 PM orlock: it stecofically says grbl on the board
11:31 PM * rue_ zooms in
11:31 PM rue_: damn...
11:32 PM orlock: annyway, i just wanted to drive 2x steppers from a nano, i was going to get a pair of those carrier boards, but then saw that whole 3x stepper thing
11:32 PM rue_: $3.50 for just that pcb isn't stellar
11:32 PM rue_: the kit is a descent deal
11:32 PM orlock: yeah
11:33 PM orlock: theres also these
11:33 PM orlock: https://www.aliexpress.com/item/1set-CNC-Shield-Expansion-Board-for-Arduino-3D-Printer-4-x-A4988-Stepper-Motor-Driver-with/32698011662.html
11:33 PM orlock: 4x steppers on an arduino
11:33 PM * rue_ thinks
11:33 PM orlock: but i only need to drive 2 steppers, and i'm limited in my verticle space
11:34 PM orlock: its nice seeing module aolutions that are not just another rammps board
11:34 PM orlock: modular solutions, even
11:35 PM rue_: :/ I didn't take pics of the controller on my new machine
11:35 PM rue_: I used larger stepper drivers
11:36 PM rue_: well, make a custom one on veroboard
11:36 PM orlock: using stepper drivers, or H bridge?
11:37 PM orlock: i wanted to be able to easily toggle between full and microsteps
11:37 PM rue_: using the 4988 drivers
11:38 PM rue_: er, no
11:38 PM rue_: mine uses drivers from a printer
11:38 PM rue_: their 3A drivers
11:38 PM orlock: printer...
11:38 PM orlock: that term has more meanings now
11:38 PM rue_: 2d printer
11:38 PM orlock: ahh
11:39 PM rue_: they take serial data for the amplitude of each phase
11:39 PM orlock: ahhh
11:39 PM orlock: big printer?
11:39 PM rue_: so I had to put a tiny13 in there to translate the step/dir into the 4 phase amplitudes
11:39 PM rue_: office, HP
11:39 PM rue_: document feeders and scanners and such
11:40 PM rue_: they have a board with 3 drivers in a row
11:40 PM rue_: so I hacked it (micocontroller came off)
11:43 PM orlock: this is.. diffeent
11:43 PM orlock: https://www.aliexpress.com/item/NANO-L298P-L298P-2A-Dual-Channel-DC-Stepper-Motor-Driver-Shield-Module-5V-12V-PWM-DC/32799216665.html
11:51 PM rue_: hah, where there is a will there is a way
11:52 PM rue_: http://ruemohr.org/~ircjunk/images/pi/IMG23Mar2018_044534.jpg
11:52 PM rue_: huh, bad orientation to take a pic of a pcb really...
11:52 PM rue_: SLA7044, check 'er out