#robotics Logs

Oct 05 2015

00:23 copycat is 3d interpolation on a gantry pretty standard for most motion controllers to have?
02:52 deshipu Nothing-: if it's a teleoperation military drone, teeth might be useful
02:52 deshipu Nothing-: otherwise I see no reason to even make it humanoid
03:01 Nothing- that's what i was thinking at first too.. applied as a weapon
03:02 wolfmanjm anyone done a selfbalancing robot?
03:04 deshipu wolfmanjm: like this? https://www.youtube.com/watch?v=P5j619mdesM
03:04 deshipu (it's not mine)
03:05 wolfmanjm no like this https://www.pololu.com/blog/528/zippy-an-arduino-nano-based-balancing-robot
03:05 wolfmanjm I can't get mine to stabilize at all
03:06 deshipu tuning the pid takes some patience
03:06 wolfmanjm I've totslly rebuilt it with more powerful motors but it still tilts in one direction and takes off
03:07 wolfmanjm I'm not sure this is totally PID issues, I'm very familiar with PID tuning :)
03:07 deshipu it wants to be free
03:07 Jak_o_Shadows The dynamics of it are a pretty well known problem. Have you got a decent model of it?
03:07 wolfmanjm but it seems even at full power it is not enough to tilt it back afer about 10° it just takes off and cannot recover
03:08 wolfmanjm if I start with it straight up it pretty much balances, but if it tilts one way then it kind of takes of in that direction and PID is full power
03:09 wolfmanjm not sure what I am doing wrong
03:09 deshipu make it higher then?
03:09 wolfmanjm I could try that :)
03:10 deshipu or put more weight at the top
03:10 deshipu (not sure if that won't have the opposite effect)
03:10 wolfmanjm but I would think that would make it worse. more top heavy so more weght pulling it over
03:11 wolfmanjm it slows the pendulum down yes so gives more time to react, that may work.
03:11 wolfmanjm I'll try that next
03:12 Jak_o_Shadows Yeah. Increases your second mass moment of inertia
03:15 deshipu height should help -- longer pendulums move slower
04:21 deshipu wow, 5 pounds for a capacitor and a vibro! https://www.kickstarter.com/projects/460355237/the-crafty-robot-the-5-robot
05:43 drebo woah this channel exsists
05:43 drebo p.rad
05:43 drebo freenode has a good userbase
05:44 deshipu of course
05:44 deshipu not that there is anything useful here ;)
05:46 drebo neither on the other channels ;D
05:58 Tom_itx so contribute.
06:20 drebo NAH
06:20 drebo nah *
10:43 doMynation Morning everyone. I'm looking for advices to start in robotics. I have a degree in software engineering and I've been developping Web software for years now. I read a lot of guides to help me choose the appropriate "starter kit" but one last question remain: Should I go with Arduino or Raspberri (in other words: Microcontroller OR Single-board-computer). What would you recommend to a guy looking to build small device with basic
10:43 doMynation AI (e.g. a small tank) using mature programming language (C# or Java preferably) ? (sorry for the wall of text).
10:49 deshipu what the tank is supposed to do?
10:58 doMynation deshipu, nothing much. Simple autonomous navigation, detect obstacles and re-orient accordingly.
10:58 doMynation It might be too much for a beginner though, maybe I'm being too ambitious too.
11:14 deshipu doMynation: what sensors?
11:15 deshipu doMynation: what I mean is, if you need any serious signal processing, like a camera image processing or sound processing, then Arduino can't handle it
11:15 deshipu also, network connectivity is tricky on arduino
11:15 deshipu but anything else will be probably easier on arduino than on the rpi
11:31 doMynation Alright, thank you very much for your help deshipu and sorry for the late answer.
11:32 doMynation Just like the guys on #arduino and #raspberrypi recommende, I'll definitely start off with an arduino.
11:35 deshipu get a bunch of pro minis, you won't cry when you fry them
11:36 deshipu and if you ever want to make a spider bot, check out my project http://tote.rtfd.org
15:31 veverak /me will receive his paycheck
15:31 veverak http://www.aliexpress.com/item/10pcs-lot-Pro-Mini-328-Mini-3-3V-8M-ATMEGA328-3-3V-8MHz-for-arduino/1967122432.html?spm=2114.031010208.3.2.3RlsHy&ws_ab_test=201556_1,201527_2_71_72_73_74_75,0_0
15:32 veverak why this still sounds too good to be true?
16:17 rue_school if you work at it, you can get them down to $1.50 ea
16:17 rue_school its true
16:18 rue_school http://www.aliexpress.com/item/USB-To-RS232-TTL-Converter-Adapter-Module-PL2303-with-Transparent-Cover-Freeshipping-Dropshipping/1985011037.html?spm=2114.01020208.3.2.oNSqdv&ws_ab_test=201556_3,201527_4_71_72_73_74_75,0_0
16:18 rue_school get some of those with it
16:18 rue_school find a lot of like 10 tho
16:19 rue_school then get http://www.aliexpress.com/item/Free-shipping-Dupont-line-120pcs-10cm-male-to-male-male-to-female-and-female-to-female/32260100368.html?spm=2114.01020208.3.12.uAb1uH&ws_ab_test=201556_3,201527_4_71_72_73_74_75,0_0
16:19 rue_school F-F dupont to interconnect them
16:20 orlock rue: http://en.crypt.net.au/TStar/
16:20 rue_school then get http://www.aliexpress.com/wholesale?catId=0&initiative_id=SB_20151005125544&SearchText=DC-DC
16:20 rue_school some power supplies for them
16:20 orlock also, chasing suggestions
16:20 rue_school crikey thats a big one
16:21 orlock i have 19x 5mm 4 leg LED's
16:21 orlock i'd like to attach them via wire to perfboard
16:22 orlock currently the best way i can think of is 4 pin header sockets, with matching crimp/solder plugs
16:22 orlock so solder wires onto ends of LED's, other end of the wires have crimped/soldered sockets, with header pins on the perfboard
16:23 orlock http://www.jaycar.com.au/Interconnect/Terminals-%26-Headers/Imperial-Locking-Headers/4-Pin-0-1-Header-with-Crimp-Pins---2-54-pitch/p/HM3404
16:23 rue_school is that a heated bed? I could never print something that big without it turning into a bannana
16:23 orlock going to http://www.jaycar.com.au/Interconnect/Terminals-%26-Headers/Imperial-Locking-Headers/4-Pin-0-1-Straight-Locking-Header---2-54-pitch---Single/p/HM3414 or http://www.jaycar.com.au/Interconnect/Terminals-%26-Headers/Imperial-Locking-Headers/4-Pin-0-1-90-degree-Locking-Header---2-54-pitch---Single/p/HM3424
16:23 rue_school screw that, use dupont
16:23 orlock nope
16:23 orlock PLA doesnt warp that much
16:23 rue_school ooooh
16:24 rue_school wait, your printing pla with no heated bed?
16:24 orlock yeah
16:24 rue_school I thought you had to have a heated bed for it
16:24 rue_school ARG
16:24 orlock hell no
16:24 rue_school wait
16:24 rue_school I AM printing pla
16:24 rue_school wtf
16:24 orlock whats the surface?
16:25 rue_school blue or green tape
16:25 orlock i had a tiny bit of lift on some of the edges of the black star
16:25 orlock the white star had almost no lift
16:25 rue_school yea, I try to print something 4x8cm and it lifts about 5mm
16:25 orlock and when it did, it was pulling the tape off the bed
16:25 rue_school huh
16:25 orlock took me half an hour to get the white star off
16:25 rue_school do you sand the tape?
16:25 orlock nope
16:25 rue_school why dosn't anything work for me
16:26 orlock http://en.crypt.net.au/TStar/20151005_221003.jpg - thats through the back of the glass
16:26 orlock using scalpel blades to slowly lever it up
16:26 orlock and a 13mm wood chisel
16:27 orlock what lifts?
16:27 orlock the print off the tape?
16:27 orlock or the tape off the glass?
16:28 orlock and apparently some of the tape has a waxy coating that needs removing?
16:46 rue_school the print off the tape, yea
16:46 rue_school hmmm
16:46 rue_school I'v tried blue and green tape
16:48 orlock Theres a setting in slicer
16:48 orlock which doesnt do what i thought it did
16:48 orlock (apparently)
16:48 orlock anyway - do you brim?
16:48 orlock and measure brimp/single layer skirts?
16:50 anonnumberanon I was making a servo bracket last week and it turned out a little horrible. First the filling wasn't dense enough because I did not know to make it better. My friend played with it last night and it took him less than 60 seconds to break the bracket.
16:50 rue_school I hvae it run the nozzel around a few times, but not really brim
16:51 orlock brims help with adhestion and prevent lifting
16:51 orlock i find i'll use a 4-6mm brim depending on the part
16:51 rue_school I also have a drool problem that gets to be a problem when the nozzel xy velocity is too slow
16:51 rue_school hmm, ok, I'll try that
16:51 orlock when moving between parts?
16:51 orlock using retraction?
16:52 orlock also, you can try lowering your Z height a bit so you "squish" the pla into the tape more
17:16 Tom_itx http://robo3d.com/
17:16 Tom_itx is that one any good?
17:29 [cube] Tom_itx: no idea, seems decent but someone posted this in #reprap lol:
17:29 [cube] http://imgur.com/a/MjTRe
17:31 Tom_itx seems they had a bad time with it
17:31 Tom_itx more than just the printer's fault i'd say
17:31 [cube] maybe it's because everything is enclosed, hard to get at
17:31 [cube] yeah, user error hehe
17:32 [cube] seems to be better options out there
17:32 Tom_itx looks like they used drawer slides on the lower axis
17:32 Tom_itx can't tell
17:32 [cube] yeah i noticed that
17:32 [cube] could just be a custom bracket
17:33 Tom_itx doesn't look all that sturdy
17:33 [cube] people seem to be impressed with ultimaker on the whole
17:33 Tom_itx but i haven't seen a reprap yet that does...
17:33 [cube] when i built my reprap it was ridiculously unstable
17:34 Tom_itx i'm not getting one.. just wondered
17:34 [cube] especially lateral movement on x-axis
17:34 [cube] the triangle is strong along the y-axis
17:34 [cube] but extremely wobbly on x
17:35 [cube] poor design on the original mendel
17:35 [cube] ended up reinforcing it bigtime
18:02 robotust1a hey
19:27 rue_school orlock, if my nozzel just sits hot it'll drool
19:27 rue_school the rate screws up the feed rate when the volecity is low
19:27 rue_school its before it even is ready to retract
19:28 orlock yeah
19:28 rue_school tried lowering z, the machine is strong enough to carve paths thru the tape on the bed
19:28 orlock it should be moving so fast all the time its not a problem though?
19:29 rue_school when it comes to the end of a trace it slows down to stop
19:29 rue_school the deaccel time
19:29 rue_school and during reaccel
19:29 orlock ahh
19:29 orlock hmm i should fiddle with those
19:29 orlock see if it cleans up my ringing
19:39 rue_school http://imgur.com/gallery/D70Olsu
19:40 rue_school we need automated cars?