#robotics Logs
Apr 09 2017
#robotics Calendar
12:15 AM jandor: may be you could hire some printwatcher
12:17 AM jandor: as a part-time job
12:17 AM jandor: to just sit there and watch
12:24 AM rue_shop3: I cant visually distinguish M5 from 10-32
12:24 AM rue_shop3: .08mm
12:24 AM rue_shop3: 32tpi
12:25 AM rue_shop3: 32tpi is 0.79375mm the M5 is 0.8mm
12:28 AM rue_shop3: the outter thread size of a M5 is 4.88mm
12:28 AM rue_shop3: the outter thread size of a 10-32 is 4.8mm
12:41 AM codepython7771: I want to build a small xy writing machine - just a simple pen and paper, but want to be precise. Any suggestions where i can start?
12:41 AM jandor: do you have experience with servos?
12:42 AM jandor: I suggest you to find a simple open-sourced 3d printer design
12:42 AM jandor: and then put a pen in place of an extruder
12:43 AM jandor: this involves working with two step motors
12:43 AM jandor: and maybe one servo to put pen down and bring it up
12:44 AM jandor: there should be a lot of ready opensource firmwares
12:44 AM jandor: like gcode-interpreters, step motor drivers, etc
12:47 AM jandor: from programmatic point of view it could be done with arduino and a simplest motor shield, for example
12:47 AM jandor: but you still need a good frame and motors
12:47 AM Jak_o_Shadows: Why the piss would you bother with g-code
12:47 AM jandor: why not?
12:47 AM Jak_o_Shadows: Slightly overomplicating things isn't it
12:47 AM jandor: once again, there should be a lot of ready software
12:47 AM jandor: which produces it
12:47 AM jandor: what do you suggest then instead?
12:47 AM jandor: a postscript?
12:47 AM Jak_o_Shadows: Do it by hand.
12:47 AM jandor: or some home-built protocol?
12:47 AM jandor: and then?
12:47 AM Jak_o_Shadows: Last time I tried to look, svg->g-code wasn't as simple as it seemed
12:47 AM jandor: build yet another vector editor?
12:48 AM Jak_o_Shadows: Not necessarily. Just the svg->plotter bit
12:49 AM mrdata: svg to dfs first probably
12:49 AM jandor: you mean interpret svg manually?
12:49 AM mrdata: no
12:49 AM mrdata: dfs is autocad
12:50 AM jandor: I was asking Jak
12:50 AM mrdata: oh
12:50 AM jandor: sorry
12:50 AM mrdata: then dfs to gcode is easier
12:50 AM Jak_o_Shadows: It's only xml. And you only need a teensy subclass of it
12:50 AM jandor: okay then
12:51 AM rue_house: Jak_o_Shadows, HPGL went out a LONG time ago
12:52 AM rue_house: I have a program for extracting some of the stuff from dxf
12:52 AM Jak_o_Shadows: Oh yeah. That then
12:52 AM rue_house: part of the dxf->NC CAM program I'm working on
12:54 AM Jak_o_Shadows: Was that up on github?
12:57 AM rue_house: er...
12:58 AM rue_house: https://github.com/ruenahcmohr?tab=repositories
12:58 AM Jak_o_Shadows: You had a github didn't you? Mostly stuff in C
12:58 AM rue_house: no
12:58 AM rue_house: its not there
12:58 AM rue_house: I'v only posted things that work to some degreee
12:58 AM Jak_o_Shadows: aha
12:58 AM Jak_o_Shadows: Fair enough
12:59 AM rue_house: oh oohohohohohoh I have to update TapeRunner
01:00 AM rue_house: how do I completely rewrite a project?
01:01 AM Jak_o_Shadows: What, in terms of git?
01:02 AM Jak_o_Shadows: If not in terms of git, I would suggest "better"
01:02 AM rue_house: what were the names of the 3 stooges
01:03 AM rue_house: I know the answer, I just want to see what order you say them in
01:03 AM rue_house: use the right order
01:03 AM Jak_o_Shadows: Where would you get the idea I would know their names?
01:04 AM rue_house: wtf, what planet you on!?
01:04 AM Jak_o_Shadows: "The Three Stooges were an American vaudeville and comedy team active from the late 1920s until the late 1960s" One a decent chunk after teh 1960s?
01:05 AM * rue_house folds his arms
01:05 AM * rue_house glares at Jak_o_Shadows
01:05 AM rue_house: W H A T P L A N E T
01:05 AM rue_house: -- or ship --
01:05 AM Jak_o_Shadows: Australia?
01:06 AM rue_house: (best translation is acceptable)
01:06 AM rue_house: australia is the name of the planet or ship?
01:07 AM Jak_o_Shadows: ship
01:10 AM jandor: what is going on?
01:12 AM mrdata: australia is a continent
01:12 AM jandor: on what planet?
01:13 AM jandor: isn't it an island?
01:13 AM mrdata: a pesky little one the inhabitants call earth
01:13 AM mrdata: jandor, technically australia is both the largest island and the smallest continent
01:13 AM mrdata: on this planet
01:14 AM jandor: wtf, this planet?! AM I ON EARTH?
01:14 AM mrdata: probably
01:15 AM rue_house: he dosn't know about the 3 stooges, he's not from earth
01:15 AM mrdata: tho lag wouldnt be all that much different if you were on earth's moon
01:16 AM rue_house: or if your using a quantum modem
01:17 AM jandor: I don't know about stooges either
01:17 AM jandor: is that some kind of folklore?
01:17 AM * mrdata bets jandor is a millenial
01:17 AM rue_house: WTF
01:17 AM Jak_o_Shadows: Hey, I said I didn't know the names, not that I didn't know it.
01:18 AM rue_house: WTF!!!!
01:19 AM jandor: here we are, the #robotics, arguing about I don't even know what
01:19 AM rue_house: YOU ARE NOT FROM EARTH
01:19 AM * mrdata grabs a sharpie and labels the 3-phase motor terminals curly larry and mo
01:19 AM rue_house: AND YOUR NOT INVITING ME OFF
01:19 AM Jak_o_Shadows: jandor, I mean, I was measuring something with calipers whilst this was on
01:19 AM Jak_o_Shadows: aha
01:19 AM Jak_o_Shadows: Rue, if I could, i would.
01:20 AM rue_house: policy, policy, :[
01:20 AM mrdata: right, then. rue will not be boarding the space craft.
01:20 AM mrdata: ok
01:20 AM mrdata: who's next
01:20 AM rue_house: better be more willing to help if I can make it to orbit
01:20 AM rue_house: grrr
01:20 AM rue_house: anyone familiar with git?
01:21 AM jandor: ok, now we're about to talk real thing
01:21 AM rue_house: I need to push an ugly update
01:21 AM jandor: who plays KSP?
01:21 AM Jak_o_Shadows: I am vaguely.
01:21 AM Jak_o_Shadows: I haven't played KSP in ages.
01:21 AM rue_house: do you know how to update files to it?
01:21 AM jandor: push
01:22 AM Jak_o_Shadows: add, commit, push?
01:22 AM jandor: git add some_files
01:22 AM jandor: git commit -m "message for commit"
01:22 AM jandor: git push
01:22 AM mrdata: closest to ksp i have been, is to watch youtube videos of it
01:22 AM mrdata: scott manley
01:22 AM mrdata: for instance
01:22 AM jandor: great scott
01:23 AM rue_house: I think I have to get the repo, then overwrite the files and push them back
01:23 AM rue_house: ?
01:25 AM jandor: don't you have the repo already?
01:25 AM rue_house: https://github.com/ruenahcmohr/TapeRunner/tree/v1.0
01:26 AM jandor: err
01:26 AM jandor: I mean,don't you have a working copy of it
01:26 AM Jak_o_Shadows: OH. Yeah. You do need to pull it first.
01:26 AM Jak_o_Shadows: clone*
01:26 AM rue_house: git...
01:26 AM jandor: no, Jak
01:26 AM jandor: rue, do you know how to use git and, more important, why
01:26 AM jandor: ?
01:27 AM rue_house: no, because I dont get anyone helping me
01:27 AM rue_house: I just used git cause I can post stuff
01:27 AM jandor: ok, I see
01:28 AM jandor: Юрий, привет!
01:28 AM Jak_o_Shadows: Printing something different.
01:28 AM rue_house: git clone username@host:/path/to/repository
01:28 AM Jak_o_Shadows: I changed most of the speeds to the default. Kinda scaring me how fast it is
01:29 AM jandor: you have to clone a repo only once
01:29 AM jandor: then you have to work in your so called "working copy"
01:29 AM jandor: add and commit changes there
01:29 AM jandor: and then push it to the server periodically
01:29 AM rue_house: I'm trying to figure out how to clone it
01:30 AM Jak_o_Shadows: git clone <paste the url from github> :P
01:30 AM jandor: yep, Jak is right
01:30 AM jandor: just don't paste his smiling face into the command line
01:30 AM rue_house: git clone https://github.com/ruenahcmohr/TapeRunner/tree/v1.0
01:30 AM rue_house: Cloning into 'v1.0'...
01:30 AM rue_house: p11-kit: invalid config filename, will be ignored in the future: /etc/pkcs11/modules/gnome-keyring-module
01:30 AM rue_house: error: The requested URL returned error: 403 while accessing https://github.com/ruenahcmohr/TapeRunner/tree/v1.0/info/refs
01:30 AM rue_house: fatal: HTTP request failed
01:30 AM jandor: that will ruin it
01:31 AM rue_house: next idea?
01:31 AM jandor: refs?
01:31 AM jandor: let me clone it
01:31 AM jandor: git clone https://github.com/ruenahcmohr/TapeRunner/
01:31 AM rue_house: https://github.com/ruenahcmohr/TapeRunner.git
01:31 AM rue_house: oh
01:31 AM jandor: did the trick
01:32 AM jandor: omg
01:32 AM jandor: you've put an unmerged file there
01:32 AM rue_house: ?
01:33 AM jandor: or what is that
01:33 AM jandor: A patch for serial?
01:33 AM Jak_o_Shadows: the 'tkdialog.py' file
01:33 AM rue_house: ssls?
01:33 AM rue_house: oh, its a ... you know, dont LOOK at that code
01:34 AM rue_house: its a heap
01:34 AM jandor: ok, rm -rfing it then
01:34 AM Jak_o_Shadows: tkdialog doesn't seem so bad
01:35 AM jandor: what help do you need, rue?
01:35 AM rue_house: I got the status right, i just need to push it now
01:35 AM rue_house: commit!
01:35 AM rue_house: or something
01:35 AM rue_house: I dont know
01:35 AM jandor: I mean, do you need some help with your projects?
01:36 AM rue_house: maybe...
01:36 AM Jak_o_Shadows: add
01:36 AM jandor: because git manual can explain how to use git way better than me
01:36 AM Jak_o_Shadows: Basically: add tells git to do those files. Commit actually does the files. Push uploads
01:37 AM rue_house: :/
01:37 AM rue_house: it didn't work
01:39 AM jandor: rue
01:39 AM jandor: https://try.github.io/levels/1/challenges/1
01:39 AM jandor: please
01:39 AM jandor: you gonna need it
01:39 AM jandor: it's not a one-time problem
01:41 AM rue_house: no I have 2 mins and want to use git
01:43 AM Jak_o_Shadows: WHere was the error?
01:43 AM Jak_o_Shadows: In the add, in the commit, or in the push?
01:43 AM rue_house: the new files did not come up on the git server
01:44 AM rue_house: does commit transfer it to the server?
01:44 AM Jak_o_Shadows: nope
01:44 AM rue_house: does push?
01:44 AM Jak_o_Shadows: yup
01:45 AM rue_house: https://github.com/ruenahcmohr/TapeRunner
01:45 AM rue_house: hahhah, my gitfoo needs work
01:45 AM rue_house: how do I remove files from a repo?
01:46 AM jandor: git rm
01:46 AM Jak_o_Shadows: git rm
01:46 AM jandor: git help rm
01:46 AM Jak_o_Shadows: Note that it deletes the files off disk for you
01:46 AM jandor: and then you have to commit the deletion
01:47 AM jandor: files still stay at the repo, though
01:47 AM jandor: both locally and remotely
01:47 AM jandor: if they ever were pushed
01:47 AM rue_house: ?
01:47 AM rue_house: what if its not part of the project anymore?
01:48 AM jandor: you see
01:48 AM jandor: the deletion is recorded
01:48 AM jandor: they are deleted from current working tree
01:48 AM jandor: but you can revert them any time
01:48 AM rue_house: yea
01:48 AM jandor: since they still stay as some commit in the repo
01:48 AM Jak_o_Shadows: they stay in history
01:48 AM Jak_o_Shadows: But not directly visible.
01:48 AM Jak_o_Shadows: So you can recover them, but basically, you can easily pretend they're ogne.
01:49 AM jandor: hence, try not to add large binary files to git
01:49 AM Jak_o_Shadows: Unless they're hundreds of megabytes. Then it gets annoying cause you're still downloading it.
01:49 AM rue_house: so
01:49 AM rue_house: https://github.com/ruenahcmohr/TapeRunner
01:50 AM rue_house: tkdialog and paintsprayer.nc should not be part of the project anymore
01:50 AM jandor: sorry guys, I'm out
01:50 AM rue_house: they wont go away tho
01:50 AM jandor: it is morning here
01:50 AM rue_house: I git rm'd them, and did a commit
01:50 AM jandor: I need to sleep for two hours at least
01:50 AM jandor: c ya
01:51 AM Jak_o_Shadows: git rm'd, commit, push?
01:52 AM rue_house: forgot to commit
01:52 AM rue_house: bingo!
01:53 AM rue_house: ok, remember all that, i'm gonna ask again in about a month
01:53 AM rue_house: https://github.com/ruenahcmohr/TapeRunner
01:53 AM rue_house: there is the new project, if you want to play with it
01:53 AM rue_house: I oop'd it
01:53 AM rue_house: it oop'd nicely
01:53 AM rue_house: its not done, but it works
01:57 AM rue_house: isn't it great how you have to have a browser released this week for just about every non-hello-world webpage out there now?
01:57 AM rue_house: if your browser is more than a week old, its not supported
01:57 AM rue_house: "OUR ADS DONT WORK ON YOUR BROWSER, UPDATE IT!!!!"
01:58 AM Jak_o_Shadows: i got noscript a while back
01:58 AM Jak_o_Shadows: Got sick of the javascript
01:58 AM rue_house: :)
01:58 AM rue_house: I have a local apache with a default page with just a cat rolled up in a newspaper
01:58 AM rue_house: ,
01:59 AM rue_house: cat /etc/hosts
01:59 AM rue_house: 127.0.0.1 localhost
01:59 AM rue_house: 127.0.0.1 ad.doubleclick.net
01:59 AM rue_house: 127.0.0.1 pinterest.com
01:59 AM rue_house: 127.0.0.1 images-cdn.onsidelines.com
01:59 AM rue_house: ...
01:59 AM rue_house: there are only about 10 ad servers that do everything on the internet
01:59 AM rue_house: its stupid
02:00 AM rue_house: and I just hate pinterest
02:01 AM Jak_o_Shadows: ahaha
02:01 AM Jak_o_Shadows: 9.4mm up out of 75ish
02:01 AM rue_house: every time I see a cat rolled up in some paper, I know I'v been spared an ad
02:18 AM rue_house: hmm I should get to work on my force feedback controller again
08:40 AM jandor: hi
08:44 AM weyland|yutani: hi
08:49 AM mumptai: hi
09:07 AM veverak: hi
09:23 AM jandor: i'm angry
09:24 AM jandor: one of my students seem to fail to complete his thesis before the deadline in june
09:24 AM jandor: and now he asks me if I could complete it
09:24 AM jandor: for money
09:24 AM jandor: how to politely tell him go f*ck himself?
09:25 AM jandor: well i'm actually triggered
09:52 AM veverak: isn't it again university law?
09:52 AM veverak: or what's the proper term...
09:52 AM veverak: jandor: anyway, on our uni, afaik the student could be send to disciplinary comittee
09:52 AM veverak: or if he was allready there, thrown out of the university
10:17 AM jandor: yes, it is against the law
10:19 AM jandor: jkdsljfsdlfjksdf
10:20 AM jandor: does anyone work with gazebo?
10:20 AM veverak: maybe soon
10:20 AM veverak: :)
10:20 AM jandor: not yet?
10:20 AM jandor: okay
10:20 AM jandor: I'm trying to find info on some obscure parameters
10:21 AM jandor: I don't want to skim through the sources yet
10:21 AM jandor: but it seems to me that'll be my only hope
10:32 AM anniepoo: politeness isn't required -
10:32 AM anniepoo: and yes, you should report him to the faculty -
10:34 AM anniepoo: jandor - sorry. I think many of us on this channel have similar take on ROS, that it's a pit of such issues.
10:35 AM jandor: And I know why
10:35 AM jandor: ah
10:35 AM jandor: misread that
10:35 AM jandor: still agree
10:36 AM anniepoo: (meant 'politeness isn't required when responding to an offer to do something unethical')
10:36 AM anniepoo: jandor - trick I've found sometimes works.
10:36 AM anniepoo: ask us anyway.
10:37 AM anniepoo: Often, I find the process of explaining my problem to others helps me clarify it for myself
10:46 AM anniepoo: I suspect it's 'not that bad', but as you're finding, it's poorly documented.
10:47 AM jandor: I'm writing that article, you know
10:47 AM jandor: on gazebo sim
10:48 AM anniepoo: oh, cool
10:48 AM jandor: may be I'll translate it to english and contribute
10:48 AM anniepoo: that'd be neat
10:48 AM anniepoo: if you'd like, I'd be willing to help clean up the english, if that would be helpful
10:49 AM anniepoo: (I'm an American)
11:09 AM jandor: that would be great )
11:09 AM jandor: because otherwise it'll suffer from double translation
11:10 AM jandor: all materials I've found are in english (no surprise, though)
11:10 AM jandor: so I'm translating and interpreting them into Russian
11:10 AM jandor: then we'll have to go back to English
11:19 AM jandor: test
11:20 AM anniepoo: hello
11:20 AM jandor: hi
11:20 AM jandor: killed my x session by mistake
11:21 AM anniepoo: oops
11:21 AM jandor: was playing with emacs
11:21 AM jandor: hit ctrl-meta-backspace
11:21 AM anniepoo: so, anyway, if you translate it, I'd be willing to help copy edit.
11:22 AM anniepoo: I have gazebo installed
11:23 AM jandor: which version
11:23 AM jandor: ?
11:23 AM anniepoo: 7.5.0
11:24 AM jandor: they have released 8 on march 31
11:24 AM jandor: seems like they have fixed the friction params at last
11:24 AM anniepoo: so, dumb question
11:25 AM anniepoo: the example model is wheeled.
11:25 AM jandor: aha
11:25 AM anniepoo: how's it do the physics of the wheels - is it doing a friction model?
11:25 AM jandor: yes
11:26 AM jandor: for wheeled models to behave adequately, you have to specify friction coeeficients
11:26 AM jandor: a lot
11:26 AM jandor: mu and mu2, fdir1, slips
11:26 AM jandor: and static friction, of course
11:26 AM jandor: I hope example model has it all already
11:26 AM anniepoo: ok, and getting accurate friction values from the bot seems painful
11:27 AM jandor: you can take mu and mu2 from tables
11:27 AM anniepoo: whats fdirl?
11:27 AM jandor: since the gazebo by default uses approximated but still believable friction model
11:27 AM jandor: pyramid one
11:27 AM jandor: you can take it from physics primer
11:28 AM jandor: I mean mu
11:28 AM anniepoo: <jandor> mu and mu2, fdir1, slips
11:28 AM jandor: gazebo and ode can calculate an anisotropic friction
11:28 AM anniepoo: right
11:28 AM jandor: so mu is a frict coeffictient along fdir1
11:29 AM anniepoo: ah, fdir1 is the vector direction the coefficients are wrt
11:29 AM jandor: and mu2 is a friction coefficient along fdir2, which is calculated automatically as normal to both contact normal and fdir1
11:29 AM anniepoo: right
11:30 AM jandor: aaaand before this version fdir1 was broken
11:30 AM anniepoo: lol
11:30 AM jandor: it was expressed in world coordinated instead of local body
11:30 AM anniepoo: good grief
11:30 AM jandor: now it should have been fixed
11:30 AM anniepoo: that seems a very basic thing to be broken
11:30 AM jandor: haven't tried it yet
11:31 AM jandor: but you know, as long as mu = mu2 it doesnt' really matter
11:31 AM anniepoo: right - so anisotropy didn't work
11:31 AM jandor: I'm digging that thing right now
11:31 AM anniepoo: ok, I loaded the gazebo worlds/pioneer2dx.world
11:31 AM anniepoo: demo
11:32 AM jandor: copypasting from sdformat.org, translating, adding comments, etc
11:33 AM jandor: the fun part
11:33 AM jandor: which is not very fun actually
11:34 AM jandor: is that sdformat is broken and doesn't show half of the sdf specs
11:34 AM jandor: default values, to be specific
11:34 AM jandor: so it is better to clone the repo and see for yourself what's there and what you can put there
11:35 AM anniepoo: aaargh
11:35 AM anniepoo: ok... this seems like it's very broken
11:35 AM jandor: yep
11:35 AM jandor: but it works!
11:40 AM anniepoo: 8cP think I'm sticking with what I've got
11:40 AM anniepoo: if you type enough arbitrary coefficients into a model it can say anything
11:41 AM anniepoo: and I really doubt my ability or interest in making all these measurements
11:42 AM jandor: After I finish this thing, publish it and get some feedback, I'll tell you should it be worked with or not
11:42 AM anniepoo: eg coeff of fric of rubber wheel on indoor-outdoor carpeting probably has a coefficient that's aligned with the weave direction of the carpet
11:42 AM jandor: I think this think has sane defaults
11:42 AM jandor: *g
11:42 AM jandor: yes
11:43 AM anniepoo: well, it's a simulator. 'sane defaults' is fine, but I can get same results much simpler in blender
11:43 AM jandor: and there is a little trick to specify fdir for a wheel
11:43 AM anniepoo: in my case my robot's physics aren't that interesting
11:43 AM jandor: it has to be parallel to axel
11:43 AM anniepoo: makes sense
11:44 AM jandor: so fdir2 will be "on" the wheel
11:44 AM anniepoo: the snail has treads that actually move it
11:44 AM anniepoo: fdir2 is forward?
11:44 AM anniepoo: or down?
11:45 AM anniepoo: has to be forward
11:45 AM jandor: fdir2 will be forward
11:45 AM jandor: you see, wheels can have contacts not only at the lowest point
11:45 AM jandor: but on any point
11:45 AM jandor: it depends on what they roll on
11:46 AM jandor: so unless you want to write a plugin which recalculates fdir1 based on where the contact point is
11:46 AM jandor: simple way is to define fdir1 to be parallel to the axel
11:47 AM jandor: if you don't need to evaluate dynamics, stick to blender
11:47 AM jandor: gtg, bb
11:48 AM jandor: may be in 4 hours
11:50 AM anniepoo: yes, got it
11:51 AM anniepoo: oh fudge
11:51 AM anniepoo: I'm working on a fork of a project, and accidentally pushed to the actual project
11:52 AM rue_bed: kill the branch and refork?
11:52 AM rue_bed: or wasn't yours?
11:52 AM jandor: git revert?
11:56 AM jandor: rue_bed, no she's working with other people
11:56 AM jandor: this push might actually affect some of them
12:00 PM anniepoo: yes
12:00 PM anniepoo: I'm working on an OS project
12:01 PM anniepoo: I'm new to this part of the project, and in the 'figuring it out' stage, but working on an enhancement
12:01 PM anniepoo: so I forked, intending to send PR's, though I have push rights
12:01 PM anniepoo: I just pushed to the real project, instead of my fork
12:04 PM jandor: you might try git revert
12:04 PM jandor: this will add another commit, reverting the changes
12:05 PM anniepoo: ok, I need to keep my local changes, obviously
12:13 PM anniepoo: oh crap
12:55 PM logicmoo is now known as dmiles
12:56 PM veverak: state-graph search online
12:56 PM veverak: deshipu: ok, I implemented it faster than week
12:56 PM veverak: holded my overkill optimalizations back
01:08 PM veverak: but hey, 5s per search is bad
01:39 PM deshipu: depends on what you need it for
01:41 PM deshipu: also, "held back"
01:41 PM deshipu: it's one of those old german verbs
01:56 PM branjb: if a motor driver calls for 100 uF, can I just add two 50 uF caps in parallel, or is it not that simple?
01:57 PM Snert: yes, pay attention to voltage ratings though
01:59 PM branjb: yeah, that's what i am trying to overcome
01:59 PM branjb: limited to only ceramic caps, and ceramic caps that are 10uF + and rated for 26+ volts tend to get pricy fast
01:59 PM Snert: what is the cap value, and what is the voltage rating?
02:00 PM branjb: need 100uF
02:00 PM branjb: 26 V
02:00 PM branjb: ceramic only
02:01 PM Snert: 2ea. 200uf 16v would be right for that.
02:01 PM Snert: in series.
02:01 PM branjb: voltage rating in series doubles?
02:01 PM Snert: yep. but capacitance halves.
02:01 PM branjb: good to know
02:02 PM branjb: does voltage rating half in parallel?
02:02 PM deshipu: no
02:02 PM Snert: no, it stays the same since each cap has the exact same voltage across it.
02:06 PM Snert: and trying to get 100uf in ceramic is hard to find. Ceramics generally are not that big.
02:06 PM branjb: yeah
02:07 PM Snert: I wouldn't even try. 100uf is electrolytic territory.
02:07 PM branjb: it's for a high pressure environment where most other caps crush and fail
02:07 PM branjb: ie, electrolytic/film caps
02:07 PM Snert: oic.
02:07 PM branjb: weird project
02:08 PM Snert: that encased probe you drop down inside something you were working on?
02:09 PM branjb: a control board for a pan/tilt camera on an underwater ROV
02:10 PM branjb: ends up getting ~10k PSI on all components
02:10 PM Snert: why not encase the electronics inside something that can withstand the pressure?
02:10 PM Snert: rather than expose the electronics to direct pressure.
02:11 PM Snert: but yea, thems is tough requirements to meet.
02:12 PM branjb: cost i think
02:12 PM branjb: and weight
02:12 PM Snert: pressurize the container to 5K psi ... then at depth the container itself only has to withstand 5k psi.
02:13 PM branjb: cheaper to fill an enclosure with mineral oil than to have a heavy metal case in a weird spot on the ROV
02:14 PM Snert: yea, I got no grasp on that sort of stuff. tis is a WOW project.
02:14 PM branjb: i don't really know actually, other than thems the requirements
02:15 PM Snert: 10k psi is how many feet down?
02:15 PM deshipu: both
02:15 PM branjb: 5km
02:16 PM deshipu: and one hand
02:16 PM Snert: 32 feet per atmosphere so......
02:16 PM Snert: which is 17 pound per atmosphere....
02:17 PM Snert: eh, scrooit. No math on Sunday :)
02:17 PM branjb: i think in actuality it's like 8k PSI @ 5km
02:17 PM branjb: but tested @ 10k PSI
02:18 PM deshipu: but are they nautical feet or duck feet?
02:19 PM Snert: meeters.
02:19 PM deshipu: metric feet, I see
02:20 PM branjb: 10k metric feet
02:21 PM Snert: is that like my email?
02:21 PM Snert: don't mess with my email.
02:21 PM Snert: hahaha
03:21 PM rue_house: metric feet?
03:22 PM rue_house: a metric foot is 30cm, right?
03:22 PM rue_house: .48cm shorter than an imperial one, but the same price
03:23 PM rue_house: lets just use 3.1710025e-17 lightyears
03:35 PM Snert: I prefer furlongs per fortnight.
03:39 PM rue_shop3: is a 24c01 1kbyte or bit?
03:39 PM rue_shop3: bit
03:39 PM rue_shop3: 128 bytes
03:40 PM rue_shop3: suppose thats not enough for a fat fs
04:54 PM Tom_L: rue, no maybe a thin one would fit
05:01 PM jandor: how goes it?
08:08 PM rue_house: hacking printer
08:24 PM jandor: writing stuff
08:24 PM jandor: I've dived into gazebo source code
10:15 PM rue_house: :)that not how you do it
10:22 PM rue_house: anniepoo, ever seen a usb touch screen?
10:22 PM rue_house: is screen, is mouse, is keyboard
10:22 PM rue_house: is usb
10:22 PM rue_house: is not vga, is not dvi
10:22 PM rue_house: is not hdmi
10:23 PM zhanx: is slow
10:23 PM rue_house: yea
10:23 PM rue_house: is from HP printer :)
10:24 PM rue_house: I have one hour to rescue a 4L jug of milk from the store, get it home, and give it some tea
10:24 PM zhanx: better hurry then
10:24 PM rue_house: yup.
10:25 PM * rue_house takes another sip of pop
10:26 PM rue_house: ok. I'm ready
10:26 PM * rue_house looks for the car keys
10:48 PM rue_house: made it
10:56 PM rue_house: git wont push my file change
10:56 PM Tom_itx: pull it then
10:56 PM Tom_itx: i don't use it
10:57 PM rue_house: it wont update the file on github
10:57 PM Tom_itx: seems like one more tool to have to learn
10:57 PM Tom_itx: may be useful for groups
10:58 PM Tom_itx: rue_house
10:58 PM Tom_itx: how many canadian geese do you actually have in canada?
10:58 PM Tom_itx: seems we have most of them here
10:58 PM Snert: a gaggle.
10:58 PM Tom_itx: and you're welcome to have them ALL back
10:58 PM rue_house: like all the rich people they go south for the winter
10:59 PM Tom_itx: some stay forever
10:59 PM Tom_itx: like a vacation paradise
10:59 PM Snert: we call them snowbirds.
11:00 PM Tom_itx: i swear they should declare open season on them for a good spell
11:01 PM Snert: americans don't eat much geese compared to the asians.
11:02 PM rue_house: or slugs, or bugs, or dogs....
11:02 PM rue_house: americans are just damn pickey eaters!
11:02 PM Tom_itx: i don't get the whole fried bug thing
11:03 PM Snert: I'll never eat bugs. Chocolate covered grasshoppers? YUCK.
11:04 PM Tom_itx: i just hope the canadians aren't as annoying as their geese
11:04 PM rue_house: Healthy diet of salt, sugar, MSG, and Maltodectrin-inosinate-guanylate-caseinate.
11:04 PM Snert: with a side dish of cigarettes, beer and weed.
11:04 PM rue_house: (cancer causing in california)
11:04 PM Tom_itx: makes us ammune to just about everthing. we're slowly being preserved
11:05 PM Tom_itx: Snert, not all of us
11:05 PM Tom_itx: that's just the stereotypical view
11:05 PM Snert: some are sin free, true.
11:05 PM rue_house: cause like its not bad enough now, were gonna want some fresh trump in 100 years
11:06 PM rue_house: "THE BEST BEFORE ON THIS TRUMP WASN'T STAMPED!"
11:10 PM zhanx: fun fact rue is off his meds
11:11 PM rue_house: I went for milk and came back with a bag of chips too
11:11 PM rue_house: :( I was upsold
11:12 PM rue_house: what did Trump do this week anyhow? did he say its ok for industries to dump raw waste into drinking water sources yet?
11:13 PM rue_house: did he create insentives for burning tires?
11:13 PM rue_house: I dont follow the news
11:13 PM rue_house: did he rename obamacare into trumpcare?
11:14 PM rue_house: did he learn to read?
11:15 PM Snert: if he keeps this up I'll give him another 4 years.
11:20 PM zhanx: rue he is doing fine right now so as long as Canada stopping dumping raw waste in the St Lawrence river you can't talk
11:22 PM rue_house: hu!?
11:23 PM rue_house: ugh
11:23 PM rue_house: is it those stupid french again?
11:24 PM rue_house: well I suppose I need to shut down the shop
11:27 PM zhanx: yep the last dump was an est 4 million Liters
11:38 PM rue_shop3: didn't hear about it, amazing how the news can keep things quiet out here
11:40 PM zhanx: New york state has a lawsuit and tried to get an injunction and yea Canada ignored it. They dump on a regular basis and claim it "flooded"
11:54 PM rue_shop3: sewer?
11:54 PM rue_shop3: or soemthig from a us-owned ford plant?
11:56 PM zhanx: no its the waste treatment plant on the edge of the river on the canada side.