#robotics Logs
May 05 2017
#robotics Calendar
12:36 AM anniepoo: 8cD Y axis slide assy is done 8cD
02:34 AM rue_house: just install asterisk
02:41 AM rue_bed: dont go into business with friends!
03:25 AM agravier[away] is now known as agravier
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05:15 AM Tom_itx: rue_bed, not getting the parts out ehh?
05:16 AM * theBear gets his parts out
05:16 AM theBear: hehe, rude !
05:31 AM yCrazyEdd is now known as CrazyEddy
08:15 AM rue_bed: Tom_itx, no there was a emotional inncodent and its all come apart now
08:17 AM Tom_itx: sas
08:17 AM Tom_itx: sad
08:42 AM Ahmed___: hi all would someone help me with this ?
08:42 AM Ahmed___: https://electronics.stackexchange.com/questions/303547/line-follower-robot-using-pid-control
08:42 AM Ahmed___: ace4016: :D
08:42 AM rue_bed: learning too much about personalities
08:42 AM rue_bed: value and cost
08:43 AM rue_bed: one person proving themself right, cost the entire team
08:45 AM rue_bed: sensor 0, sensor 2, sensor 4, sensor 4?
08:46 AM rue_bed: and then you ask if they are 1, not zero
08:46 AM Ahmed___: omg a mistake
08:46 AM rue_bed: if they are 1, they are not zero
08:46 AM Ahmed___: how to correct the condition ?
08:46 AM rue_bed: it also follows that if they are not 0, they are not 1
08:47 AM rue_bed: er, sorry
08:47 AM rue_bed: still asleep
08:47 AM rue_bed: it also follows that if they are 0, they are not 1
08:47 AM rue_bed: when you stack if's its like saying 'and'
08:48 AM Ahmed___: ok
08:48 AM Ahmed___: so how would I correct it ? I would like to see if they are all one black and then all of them became white
08:49 AM rue_bed: you want to execute the code if they are all 0 or all 1?
08:49 AM Ahmed___: no
08:49 AM Ahmed___: if they are all 0 then they became all of them 1
08:49 AM rue_bed: aaah
08:49 AM rue_bed: so you have to remember what they were last time you looked
08:50 AM rue_bed: so you have to have a copy of the last info
08:50 AM rue_bed: buuuut, you also have to remember that there will be a slight timing difference between them all going from 0 to 1
08:50 AM rue_bed: it might be microseconds, but thats ages to the controller
08:51 AM Ahmed___: can you write a pesudocode please? www.pastebin.com
08:51 AM Ahmed___: I will implement it
09:00 AM Ahmed___: rue_bed: would you help me please ?
09:07 AM rue_house: cant, have to eat and leave for work
09:07 AM Ahmed___: ok
09:07 AM Ahmed___: so I have to check if prev ( if (current) ) { }
09:07 AM rue_house: sounds right
09:08 AM Ahmed___: thanks
09:08 AM rue_house: and them update prev to current
09:08 AM Ahmed___: prev = current;
09:08 AM Ahmed___: I got the problem
09:08 AM Ahmed___: but thanks a lot
10:38 AM nobody3099: hi all
01:45 PM SpeedEvil: http://imgur.com/gallery/W9ltQCI
01:46 PM robopal: creepy
01:46 PM robopal: but interesting
01:53 PM SpeedEvil: I just watched the first two cute coins.
01:53 PM SpeedEvil: I diddn't see the next
04:28 PM z64555: Anybody happen to know where I can get some good linear actuators?
04:30 PM z64555: scouting for parts for the 3d printer I'd like to build
04:34 PM mrdata: i drove out to mississauga and got some
04:34 PM mrdata: retail
04:35 PM mrdata: oh wait, mine were linear pneumatic actuators
04:35 PM z64555: That would be a heck of a roadtrip for somebody from Texas. :P
04:39 PM z64555: oh, just to make sure. linear actuator uses a continous motor, while a linear servo uses a stepper?
04:49 PM SpeedEvil: No
04:50 PM SpeedEvil: Linear actuators usually use conventional motors, and a ball screw or some other mechanism to make it linear
04:51 PM deshipu: we just got so good at conventional motors, that it doesn't make sense to use anything else
04:51 PM deshipu: z64555: depending on the size, you can get some at furniture stores
04:52 PM deshipu: z64555: also automobile parts
04:52 PM deshipu: and there are those tiny stepper motors for driving camera lenses that come with a screw and a slider
04:53 PM SpeedEvil: If your question is 'how do I make a 3d printer' a reasonable starting point is to consider if you are in fact smarter than every successful 3d printer designer in the past.
04:54 PM SpeedEvil: If your design differs lots from theirs, and has similar goals
04:55 PM SpeedEvil: Or, indeed, anything
05:00 PM z64555: ok, it looks like the linear servo is just an actuator but with a servo controller on it
05:01 PM z64555: My question isn't "how do I make a 3d printer," I'm asking for a specific part, the actuator.
05:02 PM Tom_itx: you want linear actuators or linear steppers?
05:03 PM Tom_itx: http://www.linengineering.com/products/stepper-motor-linear-actuators/?utm_source=adwords&utm_medium=cpc&utm_term=linear%20stepper&utm_campaign=linear%20stepper&gclid=CLGt6pfa2dMCFUK2wAod3sgODQ
05:03 PM z64555: preferabbly steppers, my plan is to gut them and drive four of them from the same motor, then re-use the other steppers for the other axes and use belt drives
05:05 PM Tom_itx: http://www.zaber.com/products/product_group.php?group=T-LSR&linkid=adwords&gclid=CNL5qdXa2dMCFQODaQodKJkGBg
05:06 PM * z64555 waits several minutes for the pages to load
05:12 PM z64555: something like the LE version on the first page, but I need space on the screw to mount a timing pulley
05:14 PM z64555: definitely not the servo on the second page, out of budget and I won't be using the platform for anything
05:21 PM Tom_itx: http://www.robotdigg.com/category/8/Linear-Stepper
07:37 PM rue_house: I have a linear stepper!
07:38 PM DagoRed: sweet!
07:40 PM DagoRed: I assume you built one?
07:42 PM rue_house: no
07:42 PM rue_house: its from a daisywheel printer
07:42 PM Snert_: sounds like a regular stepper coupled to a ball screw. Like a 3d printer.
07:43 PM rue_house: no, its actually got .... I suppose I could take a pic eh?
07:43 PM rue_house: I'll do it later, I'm tired
07:43 PM Snert_: yes please do this sounds interesting
07:43 PM Snert_: k
07:43 PM rue_house: (its a bar with teeth, and 4 lienar poles)
07:44 PM Snert_: ok. then 4sure you gotta show us :)
07:44 PM Snert_: I like the idea. It might provide vertical height on a robot arm.
07:45 PM Snert_: I can just about picture it too. I've seen daisywheel lashups like that before. An old apple daisy wheel.
07:56 PM nnumerals is now known as solol
08:03 PM theBear: daisywheel lashups would be a good stripper or porno name
08:03 PM theBear: i mean for an actor/tress, not a movie/show
08:41 PM rue_house: http://ruemohr.org/~ircjunk/images/linear_step1.jpg
08:41 PM rue_house: http://ruemohr.org/~ircjunk/images/linear_step2.jpg
08:41 PM rue_house: eh?
09:07 PM z64555: Huh, perferated strap
09:07 PM z64555: I'd love to see that stripped down
09:08 PM z64555: damnit, theBear
09:08 PM z64555: lol
09:08 PM Tom_itx: how much quicker is the PCIE buss over pci?
09:13 PM DagoRed: a lot.
09:14 PM theBear: like, a super lot
09:14 PM theBear: even one lane worth of it
09:15 PM Tom_itx: so a ssd with pcie is better than a regular ssd?
09:15 PM Tom_itx: by a factor of what?
09:16 PM theBear: i dunno, sata is super-fast too, and usually integrated into the chipset these days, pretty sure no current ssd can saturate one of them yet, gotta be getting close tho
09:16 PM Tom_itx: http://www.tomshardware.co.uk/samsung-sm961-ssd,review-33585.html
09:16 PM Tom_itx: checking that out a bit
09:17 PM Tom_itx: already using the samsung evo series
09:17 PM theBear: i ain't kept up since about 2nd gen ssd stuff years ago now, but evo do seem very popular
09:22 PM z64555: thought sata 2 was on the scale of GB/s
09:22 PM z64555: or maybe that was sata 3?
09:22 PM * z64555 gets is all mixed up
09:23 PM Tom_itx: it may be a while before they show up anyway
09:24 PM Tom_itx: right now they're OEM but a couple places have em
09:28 PM Tom_itx: 1.6GB/sec *random*
09:28 PM theBear: lotta online megastore kinda sites seem to have em these days, tho i spose they're kinda public-dealing oem's when i think about it, just that i kinda been an oem over the years and not noticed it... still effing expensive tho.... these days yer get a terabyte or two of crazy fast real hd for under $100, and raid1 is pretty cheap on modern hws, 2 or even more of them raid5'd up into a megaduperfast drive that can afford to partially die without
09:28 PM theBear: losing data is lookin good to me last ew years
09:28 PM Tom_itx: gotta watch for the controller though
09:28 PM Tom_itx: there may be 2 with different controllers, i'm not exactly sure
09:29 PM theBear: mmm, the random factor is attractive... recently i been using casper/ashitaka's old trick, for things like tmp build dirs and heavy duty stuff use a ramdrive/tmpfs kinda mount, and if you DO run out of yer several gb's of ram anything fairly static in there will just neatly shuffle off to yer swap drive, effecitvely making a lotta stuff happen on a ssd at native system ram speeds without even touching the drive
09:29 PM Tom_itx: it would show improvements in things like video processing probably
09:30 PM Tom_itx: mine uses all cores to process
09:31 PM Tom_itx: but i've got a cheapass video card too
09:31 PM theBear: no doubt, if i ever workout how to do that kinda thing... these days i do enjoy having a handful of various os and setup vm's on hand for odd jobs like flashing/fiddling silly fones with silly proprietry software and protocls, for example un-effing/no-booting/bootlooping iThings for friends
09:32 PM Tom_itx: i keep 4 drives in my main box
09:32 PM Tom_itx: 2 are same os but one is 32bit other is 64bit
09:32 PM Tom_itx: need to maintain older software on one
09:33 PM Tom_itx: and a shared data drive for both
09:33 PM theBear: i had what i 99% sure is a sata interface 256mb stick looks like that link image outta an old very-drowned mac air i inherited sitting here for years with a one-end-smashed sata cable and a snipped molex ready to wire up and use somewhere, but meh, i'm so busy getting nothing done these days, tho hot-damn i'm good at getting the nothing done, and i do it quick too !
09:33 PM Tom_itx: sometimes it bitches when i switch os
09:35 PM theBear: here's a handful of select lines i copied from my still live (silly reliable machine over th eyears) everything server, *.rememberit.com.au web mail and auth. dns, mysql, security cam/motion detect recordies etc, but it's very close to retirement i feel
09:35 PM theBear: 17:24:30 up 299 days, 9:42, 4 users, load average: 0.60, 0.49, 0.51
09:35 PM theBear: Linux curly 3.3.8-gentoo #12 Fri Sep 27 21:13:52 WST 2013 i686 Pentium III (Coppermine) GenuineIntel GNU/Linux
09:35 PM theBear: 4 Start_Stop_Count 0x0013 015 015 020 Pre-fail Always FAILING_NOW 87846
09:35 PM theBear: 9 Power_On_Seconds 0x0012 001 001 020 Old_age Always FAILING_NOW 53682h+59m+02s
09:36 PM theBear: those 2 smart failing lines are for the two 6gb mirror/raid1 drives that basically got everything outside the db/mail/website data and system logs <grin> and one of those warnings been sitting there for well over a year now :)
09:36 PM Tom_itx: not even sure what processor is in my server box
09:36 PM Tom_itx: it was a freebie tossout from someone
09:37 PM theBear: Vendor: Phoenix Technologies, LTD Version: 6.00 PG Release Date: 07/17/2002 -- hmm, guess i updated the bios a few years ago... sure it used to be dated '99
09:37 PM Tom_itx: i blow the cobwebs out of it once in a while but that's about it
09:38 PM theBear: yeah, this was, at least the box and first psu and mobo/cpu (it had a handful of psus/recaps now, but it's been running fulltime 24/7 probly over a decade outside of the few weeks when i moved back across the country here, effing ridiculous !) a gift from a work friend that just got a new one at the time
09:39 PM Tom_itx: this was sitting by the curb in the trash
09:39 PM theBear: kinda feel like it deserves some kinda special retirement party, the old gold watch and fancy dinner kinda package, only more for a p3 and some poor ancient hd's than an old cop
09:40 PM Tom_itx: you don't get those anymore
09:40 PM Tom_itx: they call you in for a private meeting nowdays
09:40 PM Tom_itx: give you 5 min to clear out your shit
09:40 PM theBear: mmm, most of my last few years desktop and "tv" machines have been curb pickups... not to mention to 15 or 20 (--> 5 or 8 by the end of this week i thinkin, 100% working and ready to dtv etc) all >30" tvs lying all around the house in various states of frankenstrippage
09:41 PM theBear: yeah, but i'm better than that, and it really is mindblowing how damned rock solid this old machine has been.... effing p3 1ghz ffs, must be 1000's, maybe 10's of 1000s of days with barely a hiccup
09:42 PM theBear: and those poor hds.... i can't even remember when 6gb was considered worth using for anything anymore... running so long that it run outta bytes to count age so insists that it's already dead every day or so in the slow logs dept !
09:45 PM theBear: even the poor max'd out 512mb of 100mhz ram, running all that mail server and db and website and motion detecting and then realtime encoding... i really gonna miss the feller when he's gone, tho i suspect i'm gonna enjoy ridiculously faster db and oooh yeah, it ram and disk proxies the lan for me too, i mean, even the oldest machine i got parts to put together now will just be so much more everything...
09:45 PM theBear: i'll be able to up the camera framerate into the double-digits and not have the thing bottleneck into a timewarp it can't escape if something out the front AND in the backyard moves at the same time ! so exciting
09:46 PM DagoRed: Tom_itx: after working in storage... PCIE is at least 4x faster than sata.
09:46 PM DagoRed: When done right.
09:51 PM Tom_itx: so where does the bottleneck end up on these? the PCIe buss, the ssd controller or the NAND itself?
09:51 PM DagoRed: PCIE bus, SSD controller isn't that far behind.
09:52 PM DagoRed: The SSD controller only gets slower with use.
09:52 PM Tom_itx: they put a new controller on these
09:53 PM DagoRed: doesn't matter when, it's because of the wear leveling over time.
09:53 PM DagoRed: A lot of advanced SSD's have a wear leveling indicator.
10:00 PM Tom_itx: what does the 'pro' series have over the standard samsung evo series?
10:00 PM zhanx: started my new job today
10:04 PM DagoRed: not a clue
10:04 PM DagoRed: doing what zhanx?
10:04 PM * DagoRed found out today he needs to start his search for a new position.
10:05 PM zhanx: DagoRed: Diesel Maintenance Supervisor / Lead
10:05 PM DagoRed: not bad
10:05 PM DagoRed: that's good money and you still get your hands dirty... ish
10:06 PM zhanx: yea today was mess with the new guy today
10:06 PM zhanx: I failed to play the game for them
10:08 PM DagoRed: aww... you're not as dumb as they look.
10:09 PM zhanx: dump truck camel leaf spring weigh like 750 pounds, show the new guy how to install them (new guy besides me is a kid)
10:10 PM DagoRed: ahh
10:10 PM zhanx: yea, i am big, but not that big. installed 2 sets in 20 minutes the easy way
10:14 PM DagoRed: nice
10:15 PM zhanx: DagoRed: i did this in the army and way worse, so i was expecting the "mess with the newbie" on day one
10:15 PM DagoRed: understood.
10:16 PM zhanx: i love to disappoint people that bet on me failing
10:40 PM z64555: what's the easy way, btw?
10:40 PM zhanx: z64555: cherry picker
10:40 PM z64555: huh, used it as a crane?
10:41 PM zhanx: yep
10:41 PM z64555: nice
11:19 PM z64555: hm, what's a super nut? (in terms of lead screws and linear actuators)
11:20 PM zhanx: has something to hold it in place, like a key
11:21 PM z64555: so, it's a bushing that's threaded on the outside?
11:21 PM z64555: the lead screw spins freely inside of the super nut
11:21 PM z64555: ?
11:22 PM zhanx: how is the bushing held etc.
11:22 PM zhanx: it could be a nut with a bearing in the center held with a pin
11:22 PM z64555: heck if I know, I'm looking at a catalog that just shows the part and a lead screw that's sitting inside it
11:23 PM zhanx: k
11:23 PM z64555: there doesn't appear to be any worm screw to affix the super nut to the lead screw
11:23 PM zhanx: one end should have a thread, center is open with a way to pin the center so you can replace it
11:26 PM z64555: Yeah, I think it's just a type of bushing. I'm looking at a different version that is flanged to be mounted to a surface perp to the axis of the lead screw
11:27 PM z64555: It prevents linear motion in 2 axes, and does not transfer rotational motion to linear motion in the third axis
11:28 PM DagoRed: so... should I apply for this job in robotics?
11:28 PM z64555: I dunno
11:28 PM DagoRed: It's keeping my pay low... but path planning, image processing, and embedded systems...
11:28 PM DagoRed: sounds too cool
11:29 PM z64555: Will it pay your bills sufficiently?
11:30 PM DagoRed: mostly
11:30 PM z64555: hmmm, wait a minute, I see another version of the super nut that's advertised as having anti-backlash capabilities... That's needed if your transferring rotational motion to linear.
11:31 PM * DagoRed needs to get out of his sys admin and modeling systems gig at NOAA
11:31 PM z64555: Dago: Since you answered "mostly," will the job leave you enough time to pick up a second one to cover your total expenses?
11:32 PM DagoRed: Ok...when I say mostly I mean "Damn it I want that Triumph Tiger as a second motorcycle".
11:32 PM DagoRed: It'll suffice fine. I'm just being a little greedy.
11:32 PM z64555: I asked about bills, not luxries
11:33 PM DagoRed: The biggest issue is that it is a 1 year contract.
11:33 PM DagoRed: 1 year contract, possible extension.
11:33 PM DagoRed: It does get me closer to DC for more DoD work.
11:33 PM z64555: if you're good, you'll get the extension
11:33 PM z64555: and at the very least you have the opportunity to make connections
11:34 PM DagoRed: yeah, that's what I'm thinking.
11:34 PM DagoRed: Strange thing, I've met a lot of poeple that were straight A students in college that I am finding can't hack it as engineers anymore.
11:35 PM z64555: that doesn't surprise me at all
11:35 PM z64555: engineering is applied science
11:35 PM z64555: It doesn't matter how much you know, but how well you use it
11:35 PM DagoRed: No... engineering is nothing shy of wizardry.
11:35 PM z64555: lol
11:35 PM SpeedEvil: It's really not.
11:36 PM SpeedEvil: It's knowing specific things, and knowing what you know.
11:36 PM DagoRed: It really is... for all the wrong reasons.
11:36 PM SpeedEvil: There are many, many ways to do things, and the set of things you know will often intersect with the set of useful things to do at a reasonable cost.
11:36 PM SpeedEvil: you don't need to know how to do everything, and probably shouldn't in many cases.
11:37 PM SpeedEvil: Knowing the properties of carbon carbon composite is not actually helpful if the structure has to cost $20
11:37 PM DagoRed: The hardest part about engineering is finding out you have customers that don't know what they want, a project manager that will screw it up, a marketting person that will oversell what you already have, and then not only making it work but documenting it well enough the junior tech that keeps shitting their pants can put the damn thing together.
11:37 PM z64555: lol
11:37 PM SpeedEvil: That's not engineering.
11:37 PM SpeedEvil: That's buisness.
11:37 PM DagoRed: You clearly haven't worked as an engineer.
11:38 PM SpeedEvil: Any technical aspect of anything has that problem.
11:38 PM DagoRed: true
11:38 PM SpeedEvil: From graphical art to ...
11:38 PM DagoRed: "Engineering: Solving problems in a way you don't know you have in ways you can't explain while making it simple enough for you to use or not know it existed."
11:39 PM DagoRed: I screwed that up
11:39 PM DagoRed: But regardless, engineering is a pain... I love it but it is a major pain.
11:40 PM z64555: I still say go for that job you mentioned earlier
11:41 PM DagoRed: I am. Resume getting polished up now.
11:41 PM z64555: cheers
11:42 PM DagoRed: Plus... getting paid to play with kalman filters...
11:45 PM SpeedEvil: Most important bit is the gaussian pump to backwash the filter so it doesn't get clogged.
11:54 PM DagoRed: gaussian pump?
11:54 PM z64555: possibly a gaussian noise generator
11:55 PM z64555: but nevermind me, I'm just a rookie
11:55 PM SpeedEvil: nvm - bad joke
11:55 PM DagoRed: sad thing is that exists
11:56 PM DagoRed: SpeedEvil: Good joke, terrible audience.
11:56 PM z64555: yes, we seem to take things too seriously. :P