#robotics Logs
May 02 2012
#robotics Calendar
00:06 katsmeow-afk as a capacitance meter, it works
00:06 home_ wow
00:06 katsmeow-afk digital display on it is huge
00:07 home_ i wonder if mine does it
00:07 home_ I have one of those at our school
00:07 home_ anyways
00:07 home_ need t oget my self a host..
00:07 home_ finally got myseld a domain
00:07 home_ I really want to get a dev board and a kinect :/need
00:55 delinquentme specific name for stepper motors which slide along a shaft?
01:09 katsmeow-afk sliding motors?
01:10 katsmeow-afk how would they grip the shaft to turn it, if they are sliding all over it?
01:20 rue_house trains use sliding motors
01:20 rue_house I'm back from work
01:20 katsmeow-afk ??
01:22 katsmeow-afk where does a train slide a motor?
01:30 rue_house all the way down the track
01:30 delinquentme yeah so the motor comes pre-mounted on a shaft
01:30 delinquentme and it slides from end to end along the shaft ... or if you're holding the motor portion
01:30 delinquentme the shaft slides in and out
01:30 delinquentme thrust stepper had no luck
01:33 katsmeow-afk ok, why would you want a shaft sliding thru your stepper??
01:34 katsmeow-afk where is the stepper hollow, such that a solid shaft can slide thru it?
01:34 yla slides his shaft through your ste
01:34 katsmeow-afk :-/
01:35 thyla >_>
01:35 delinquentme in the center of the stepper
01:36 delinquentme im not 100% sure that the motor IS a stepper
01:36 delinquentme I just know that there is some kind of motor driving the shaft
01:37 katsmeow-afk what do you do with this shaft, if there's a motor sliding around on it?
01:38 delinquentme well the shaft will be fixed at the ends
01:38 delinquentme but i dont want the ends with substantial mass
01:38 delinquentme however the central sliding part can be thicker
01:38 delinquentme ( yes I know all very counter intuitive )
01:39 katsmeow-afk so the shaft is useless as a shaft, and you put a linear bearing in the stepper where it's shaft should be, so you can sling the motor side to side?
01:39 delinquentme im not sure how it works
01:39 katsmeow-afk i have never heard of such a pricey waste of material
01:40 katsmeow-afk linear bearings aren't cheap, and neither are most steppers
01:40 katsmeow-afk trashing them this way doesn't sound bright
01:42 delinquentme katsmeow-afk, like i said im not sure how it works soooo
01:42 delinquentme yeah IDK if its trashing a linear bearing
01:43 katsmeow-afk it prolly isn't trashing the bearing, but to trash a stepper to insert a bearing where the stepper's shaft should be, trashes the stepper
01:44 katsmeow-afk what is this for? a steampunk abacus?
01:46 katsmeow-afk using steppers as giant beads?
01:46 katsmeow-afk do you have a picture?
01:46 delinquentme liquid handling
01:47 katsmeow-afk how is a stepper sliding back and forth on a shaft going to move liquids? stirr them?
01:50 delinquentme hmm just not seeing it
01:50 delinquentme nah its going to move parts under a stationary head
01:51 delinquentme the nice thing about robotics for biotech?
01:51 katsmeow-afk once you take the shaft out of that stepper, it's not going to move anything
01:51 delinquentme http://img.directindustry.com/images_di/photo-g/microplate-458564.jpg <, everything is designed around these things
01:52 delinquentme like i said
01:52 delinquentme im not sure its a stepper
01:52 katsmeow-afk once you take the shaft out of that motor, it's not going to move anything
01:52 delinquentme it is a box with some kind of actuation for a rod
01:52 katsmeow-afk what is a box?
01:53 katsmeow-afk you have a box with a rod inside that swings around and bats stuff to bits?
01:54 katsmeow-afk what kinds of drugs are you on?
02:10 rizlah Is a soldering iron absolutely necessary when starting out?
02:27 rizlah be back in bit
02:47 iR0b0t1 yeah
02:48 iR0b0t1 but you can use a lighter and a rock if need be
03:42 thyla http://www.youtube.com/watch?v=gDvoe091tk4
05:59 rizlah http://pastebin.com/7NvQmf9w
06:22 rizlah Suggestions for add/removal are welcome
06:40 Tom_itx rizlah get a resistor assortment off ebay
06:40 Tom_itx cheap
06:40 Tom_itx and a walwart instead of batteries
06:41 Tom_itx with a 5v regulator and a couple caps for it
06:41 Tom_itx http://tom-itx.dyndns.org:81/~webpage/how_to/atmega168/mega168_howto_main_index.php
06:41 Tom_itx see
06:56 rizlah Yeah, was thinking of getting a 100per pack of each of those resistors from ebay at 1€ or something.
06:56 rizlah What about the comments on tools?
06:59 dunz0r rizlah: Get screwdriver and screws as well. In case you want to assemble stuff :)
06:59 dunz0r A multimeter is important. For testing conductivity for example.
07:03 rizlah Hmm. What about other stuff apart from resistors?
07:03 Tom_itx wire cutters / strippers
07:04 Tom_itx soldering iron
07:04 Tom_itx solder
07:04 Tom_itx welder
07:04 Tom_itx plazma torch
07:04 rizlah switches/capacitors/etc
07:05 Tom_itx get alot of it after you get started
07:05 Tom_itx on a per need basis or you'll end up with a bunch of crap you'll never use
07:05 rizlah Hmm, true
07:06 rizlah Just thinking of usablity. Need some basics so I can test out various things without having to wait for the delivery of a few cheap items I could have bought at the same time as the other stuff
07:09 Tom_itx 5mm leds are kinda big
07:10 Tom_itx 3mm are more common
07:11 rizlah I see, kats suggested 5mm last night
07:11 Tom_itx it's your call
07:11 rizlah I suppose size wont matter too much on a breadboard because you can locate things where you want
07:11 Tom_itx http://www.dealextreme.com/p/weitus-stainless-steel-tweezers-for-electronics-diy-2-pack-19856?item=25
07:11 Tom_itx i got those
07:14 Tom_itx and another type of straight pair
07:14 Tom_itx but i do mostly smt
07:15 rizlah Looks good
07:15 Tom_itx temperature regulated soldering iron
07:15 rizlah What about a soldering iron?
07:15 Tom_itx i got a weller but you will pay more
07:15 Tom_itx you can get a cheaper regulated one
07:16 rizlah regulated?
07:16 Tom_itx temperature
07:16 rizlah Ah
07:18 Tom_itx http://www.dealextreme.com/p/60w-soldering-station-ac-220v-123591?item=47
07:18 Tom_itx make sure you get one that works on your power mains
07:18 Triffid_Hunter rizlah: it's worth getting a proper temperature controlled iron. be aware power control != temperature control! if the adjustor dial has 1-10 instead of 150,200,250 etc, it's only power control
07:19 Tom_itx agreed
07:19 rizlah Hmm
07:19 Tom_itx and if you're not sure ask
07:20 Triffid_Hunter rizlah: picked up http://www.sureelectronics.net/goods.php?id=1593 recently. haven't put it through its paces properly yet but it's great for the price
07:20 Triffid_Hunter rizlah: I have noticed that the temp sensor in the iron is a long way from the tip, so it may not be great for larger joints
07:21 Tom_itx solder wick
07:22 Tom_itx http://www.dealextreme.com/p/soldering-remover-3mm-x-1-5m-9159?item=69
07:22 Tom_itx and flux
07:25 dunz0r rizlah: I've got an Aoyue 2900. Great soldering iron.
07:25 rizlah Hmm. Not sure if it's better to leave the soldering iron out for now, as will only be using a breadboard to begin with
07:26 dunz0r rizlah: Do that. Save up so you can buy a good one.
07:26 dunz0r It's totally worth it :)
07:26 dunz0r Wooho. My steel profiles are on their way \o/
07:26 nz0r is going to build himself a
07:26 rizlah CNC?
07:27 dunz0r rizlah: If you are starting out with robotics later, get some random motors and some transistors to drive said motors as well.
07:27 rizlah Sure. but that is a few months off at least
07:27 Tom_itx or tear apart an old printer
07:28 Tom_itx with the soldering iron you forgot to order
07:28 dunz0r Tom has a good point. A soldering iron is great for scavenging as well :)
07:29 Tom_itx you can always find old electronics
07:29 Triffid_Hunter rizlah: yeah probably a good half the parts I used with my breadboards were scavenged
07:29 Triffid_Hunter and a lot of them would have been 1000% easier to remove with the hot-air gun I have now
07:29 rizlah Hmm
07:30 Tom_itx k, i'm out
09:13 rue_house I match and raise 4
09:17 e_house looks around the t
10:05 dunz0r rizlah: Remember to write down capacitors and some LM7805s as well on your list.
10:05 dunz0r So you can power your breadboarded stuff :)
12:45 tsmeow-afk recommended 5mm instead of 3mm only because the 5mm may be cheaper, because everyone is buying 3mm, and size won't matter to you at this mo
12:47 Steffanx katsmeow-afk is reading my mind
12:47 Steffanx I just looked at something, something you can get in sizes of 3mm and 5mm :D
12:47 Steffanx I didn't know which one to choose
12:49 katsmeow-afk sorry bout that
12:50 katsmeow-afk the absolute cheapest, unless someone is dumping 5mm parts, is chip leds, but those are a pain to use on breadboards because they have no leads and are bloody tiny
13:17 rizlah dunz0r: Can you suggest some capacitors to buy? Not sure what ones I would need. Also, do you know which MCU would be best ?
13:18 rizlah Also, you said "some LM7805s", how many?
13:20 katsmeow-afk depends on how many you are going to connect backwards or overheat
13:20 katsmeow-afk the mcu seriously depends on what you are going to do with it
13:20 katsmeow-afk 7905 may be hnady too
13:21 katsmeow-afk 78xx are positive regulators, 79xx are negative
13:22 katsmeow-afk get 10 78L05 in to-92 case (100ma max current), that's about $1 , get 2 - 5 7805 in a to-220 case, in case you wanna pull an amp
13:23 rizlah katsmeow-afk: with regards to the MCU, it should be as "general purpose" as possible so I can test as many things as needed without hinderance
13:25 i-make-robots hello!
13:25 katsmeow-afk still depends on what you wanna do, the general purpose 4-port 8080 clones have no usb ports, those with usb ports are all smd , etc, it's a huge tradeoff, depends on what you wanna do
13:26 Steffanx 8080 === old crap? :P
13:26 katsmeow-afk it's still general purpose, and still being made
13:26 katsmeow-afk and in a dip package, fits his protoboard
13:26 i-make-robots anyone here worked with IMUs? I want to add a 6- or 9-axis sensor to a robot that drives some 6v motors. I'm trying to research best purchase choice.
13:26 Steffanx Go AVR katsmeow-afk :P
13:26 Steffanx * rizlah
13:27 katsmeow-afk atmel makes avr and the 80xx clones
13:27 katsmeow-afk there's at least one avr number for an 80xx clone
13:27 Steffanx The good old AVR's :)
13:29 katsmeow-afk how i know i am getting off to a slow start today : i haven't started yet
13:31 Steffanx And it's 1:20 pm ..
13:31 Steffanx or am
13:31 Steffanx I always forget
13:32 katsmeow-afk i got no sleep last nite
13:33 Steffanx That was your own choice i guess?
13:34 rizlah Steffanx: What AVR would be good? I'm thinking ATmega, but there are far too many to choose from
13:34 rizlah http://search.digikey.com/us/en/cat/integrated-circuits-ics/embedded-microcontrollers/2556109?k=Atmega An example of the sheer magnitude
13:35 Steffanx I think 88 or 168 are the most popular onces to start with
13:35 Steffanx atmega88
13:35 katsmeow-afk no, it was not my choice
13:35 Steffanx The recent versions also have a extra additions, like p, pa etc. , but that doesn't really matter for most hobbyists rizlah
13:36 Steffanx The Arduino also uses the 88/168/328 rizlah, so i think it's a good choice to go with that one :)
13:36 Steffanx Arh, Arduino isn't something good :P
13:36 Steffanx katsmeow-afk, sure?
13:36 katsmeow-afk i cannot understand humans: these people spelled "campaign" right, and misspelled "goodnight" : http://abcnews.go.com/Politics/OTUS/newt-gingrichs-campaign-childrens-book/print?id=16260560 <<== in the <title.../title>
13:37 Steffanx It's "good night"?
13:37 katsmeow-afk Steffanx, i am sure i have a bad back injury and nerve damage and prolonged problems
13:37 Steffanx Ay
13:37 katsmeow-afk i said look in the title, they spelled it "goonight"
13:37 Steffanx Why you English/American split everything up anyway?
13:37 katsmeow-afk shit
13:37 Steffanx ooh :P
13:37 Steffanx oh
13:38 Steffanx I never read the text between the title-tags
13:38 katsmeow-afk it's shown in the browser titlebar too <sigh>
13:39 Steffanx There is a reason why i never read it
13:39 Steffanx http://www.naffets.nl/share/a-20120502-202931.png
13:57 i-make-robots ah well. got my answer elsewhere. cheers!
18:30 Gevallen_Engel hihi
20:22 Tom_itx katsmeow-afk, what size was the outer holes?
20:22 Tom_itx i forgot
20:47 tsmeow-afk takes a few minutes to find the calipers a
20:49 katsmeow-afk 0.235 is a 0.0005 press fit for me,, i think you said 6mm
20:50 katsmeow-afk tobbit, what's 6mm equal?
20:50 katsmeow-afk tobbor, what's 6mm equal?
20:50 katsmeow-afk !tobbor what's 6mm equal?
20:50 katsmeow-afk !tobbor help in whatever language you use
20:51 katsmeow-afk !tobbor !help in whatever language you use
20:51 katsmeow-afk hmm
20:52 katsmeow-afk 6mm = 0.0236
20:52 katsmeow-afk that's good
21:40 katsmeow-afk mouw
21:57 Tom_itx katsmeow-afk, pics to come
21:59 katsmeow-afk kewl
22:08 Tom_itx http://tom-itx.dyndns.org:81/~webpage/kat/hub4.jpg
22:08 Tom_itx http://tom-itx.dyndns.org:81/~webpage/kat/hub5.jpg
22:08 Tom_itx http://tom-itx.dyndns.org:81/~webpage/kat/hub6.jpg
22:09 Tom_itx the left one was a setup / test part
22:10 katsmeow-afk *very* nice
22:11 katsmeow-afk look slike one hole blew out on the one on the right?
22:11 katsmeow-afk er, left?
22:11 Tom_itx yeah i had to figure out the best way to drill those
22:11 Tom_itx that wasn't it
22:12 katsmeow-afk how did you do it?
22:12 Tom_itx so it's a scrap part
22:12 katsmeow-afk send it too, unless you need it
22:12 Tom_itx i had to drill a pilot hole first
22:12 Tom_itx i don't need any of them
22:12 katsmeow-afk even the mill walked the bits?
22:13 Tom_itx now the question is, whether i want to press fit the hub or run a reamer thru it and slide it on the shaft
22:13 Tom_itx i left it .004 undersize i think
22:13 katsmeow-afk is there a setscrew hole in it?
22:13 Tom_itx nope
22:14 Tom_itx not yet
22:14 Tom_itx if i press it, there won't be
22:14 Tom_itx and the only way i will press it is to heat the hub and freeze the shaft. if that doesn't work, i'll ream it out
22:14 katsmeow-afk how about if i get a shaft size mic'd, and you can ream to +/- .0005 that, and i can tap it in, and torque the setscrew?
22:15 Tom_itx it should drop right on the shaft
22:15 Tom_itx i have a shaft
22:15 katsmeow-afk shipping it in an envlope would be much easier than with a shaft thru the hub
22:15 Tom_itx meh, it'll fit
22:15 tsmeow-afk shall leave it up to
22:16 Tom_itx i haven't tried the heat method in a long time
22:16 Tom_itx it does work but you only get one chance to get it right
22:16 katsmeow-afk umm,,,, er,, umm, if you ,, right
22:17 katsmeow-afk because it can cool too fast and sieze on the wrong place
22:17 Tom_itx how long does the shaft need to be? 3"?
22:17 katsmeow-afk sure, if you put it centered on a 3", i can fit everyting around it and trim to fit
22:18 Tom_itx i was gonna press it toward one end
22:18 Tom_itx leaving about 1/2" shaft exposed
22:18 katsmeow-afk witht he disk towards the center?
22:18 Tom_itx yes
22:18 katsmeow-afk cool
22:18 Tom_itx the smooth part of the hub would be toward the short end of the shaft
22:19 tsmeow-afk
22:19 rrywolf hops on katsmeow-afk's
22:19 tsmeow-afk looks at furry wolf on fishst
22:20 rrywolf likes fishsti
22:20 Tom_itx those rings were a pain in the ass
22:20 tsmeow-afk sets the entire plate elsewhere for the furry
22:20 rrywolf squishes under katsmeow-afk's plate, so as not to be on the fishst
22:20 katsmeow-afk rings? the discs?
22:20 Tom_itx yeah
22:21 katsmeow-afk i figured they'd be difficult to do well, but you did that center one perfect, near as i can tell from here
22:21 Tom_itx it's pretty close
22:21 Tom_itx the right one is for you to cut
22:21 katsmeow-afk yeas, for coil layouts
22:22 katsmeow-afk wonderful :-)
22:22 Tom_itx you can etch the copper off if you want
22:23 katsmeow-afk i will for sure on the center disc, at least the outside inch
22:23 katsmeow-afk eddy currents and all that being detrimental
22:24 katsmeow-afk the copper can't weigh much, but it might add enough to strength to leave it on at the center
22:24 Tom_itx so was that what you described?
22:24 katsmeow-afk very much so, like you saw the pic in my head
22:25 tsmeow-afk hopes this isn't $100/hr labor or shop re
22:27 katsmeow-afk but do ship it with no discs bolted to the hub, so shipping gorillas cannot fracture the disc or bend the shaft
22:27 m_itx goes to sh
22:28 tsmeow-afk looks h
22:29 lok gig
22:29 orlok http://www.ebay.com.au/itm/Rack-Pinion-Car-Parts-Holden-LC-LJ-Torana-/330724770660?pt=AU_Car_Parts_Accessories&hash=item4d00bb8364
22:29 orlok "All items come from a smoke free environment."
22:30 katsmeow-afk hey! i have ~30 electric-boost versions of those!
22:31 furrywolf do you run a scrapyard, or are you just a redneck like me who accumulates stuff? :)
22:31 katsmeow-afk those long blank lenghs of steel tube, on mine are 3-phase electric motors with ball nuts on the shaft
22:31 orlok furrywolf: i just need a new steering rack for me car
22:32 katsmeow-afk i got them for almost nothing, really nothing since the guy who i was paying almost nothing sold the business and left
22:32 orlok i just find it funny "smoke free enviroment".. its a steering rack from a 40 year old car.
22:32 furrywolf orlok: I was asking kats... since she has twenty of something most people consider two of to be plenty.
22:32 orlok oh, haha
22:33 orlok no redneck would collect what she has.. they are from a lexus iirc
22:33 katsmeow-afk furry, i wanted the bearings for robot joints, thought the ball screws mught be worh something somewhere (don't know where yet tho)
22:33 furrywolf might even be useful as a complete unit... high-strength high-speed linear actuators.
22:33 katsmeow-afk yeas, Lexus had a big recall on these, afaik the problem was the sleeve bearing binding at extreme wheel angles
22:34 katsmeow-afk yeas, but only 6" stroke?
22:34 furrywolf useful for something, I'm sure. heh.
22:35 furrywolf how about building a hexapod mill out of six of them?
22:35 katsmeow-afk for all the very pricey bits in these things, the sleeve bearing is a .020 slip of nylon in a bushing, handling all the side thrust of the steering when it's at limits
22:35 katsmeow-afk stroke is too short
22:35 furrywolf a hexapod gets lots of movement with not much stroke...
22:36 katsmeow-afk i did think a lil of making cheapo ball-rods for these nuts tho, but i can't see how i'd make them accuartely
22:38 katsmeow-afk http://designerthinking.com/Lexussteering.html
22:39 furrywolf those would make a really cool hexapod mill, actually... I assume they have no built-in position feedback though?
22:39 katsmeow-afk the position feedback is on the input shaft, i have not tested it's accuracy, but there's no slop in the rack or drive gear
22:41 furrywolf bolt six of them to trunions, put a platform on top, build a nice big spindle, install emc2. :)
22:42 katsmeow-afk see the pic at the bottom? that was ONE HAUL , i got more
22:43 katsmeow-afk so i also got a lot of 90 deg tierod ends, and straight-on rod ends
22:44 katsmeow-afk i wonder if i changed out the rotor, i could make a monster stepper
22:45 furrywolf why go for stepper when you have the makings of a servomotor system?
22:45 katsmeow-afk like i said, the stroke is so short it's almost useless
22:45 katsmeow-afk tehre's near zero friction tho
22:46 furrywolf dunno, I still think 6" is plenty for a hexapod mill. :)
22:46 katsmeow-afk these things are pristinely clean inside tho, cept for dust from the thrust bearing plastic at one end on the used ones
22:46 katsmeow-afk look more closely at a hexapod running, some have 2ft strokes
22:47 furrywolf yes, some do. some have 1" strokes, too. :)
22:47 katsmeow-afk show me one?
22:47 furrywolf my milling machine only has 8x3 inches of travel, so it'd beat my mill by quite a bit. :)
22:49 katsmeow-afk got one moving on youtube or somewhere?
23:15 katsmeow-afk <cough>
23:15 tsmeow-afk has about decided to stop waiting 30 minutes on pe
23:17 m_itx goes to s
23:35 katsmeow-afk i tidied up http://designerthinking.com/Lexussteering.html so it fits on one screen width, basically converted it to use the css and not tables for img display (which did work once upon a time)
23:47 katsmeow-afk <cough>
23:47 katsmeow-afk is this thing on?