#robotics Logs

Jun 09 2013

02:15 Jak_o_Shadows depends on how readily available the sensors are.
02:19 SecretFire what kinds would I need
02:19 SecretFire i was thinking about programming it in c++
02:20 Jak_o_Shadows depends on what you want to measure. I just can't imagine that you'd be able to make them. You might be better off just dispensing set amounts of nutrients, and monitoring more basic stuff like temperature, water level
02:21 SecretFire and time of light output
02:22 SecretFire Im sure if the system knew how much of a certain nutrient, it could add if it was low
02:22 SecretFire a fixed value
02:32 cjgau hey ppl has anyone here ever used a or purchased a shapeoko cnc or grbl shield
02:35 cjgau im needing a pinout diagram for the stepper motors
07:47 Jak_o_Shadows trying to figure out what degrees of freedom my future robot arm needs to reload a nerf gun
08:25 ace4016 depends on how it will go about the reload
08:25 ace4016 and which nerf gun it's reloading
08:33 Jak_o_Shadows I'm thinking one of the clip system ones. I'll figure out the trigger, clip ejection separately , the arm just needs to be able to knock the old one out of the way(or pick it up, if I mount it upside down), pick it up from a holder, and put it in.
08:40 Jak_o_Shadows So I suppose I should figure out the weight and stuff eh.
09:17 Lamp Does anyone have information on shape recognition sensors?
09:18 theBear i don't think there is such a thing
09:19 Faeks First step is defining what you mean by shape recognition sensors
09:19 Faeks (why am i in here? I'm not usually in here)
09:19 theBear lol
09:19 Lamp lol
09:20 theBear if you mean 'cameras', well, there's lots of information on cameras... but maybe you mean shape recognition software
09:21 Lamp I want to be able to recognise a variety of object
09:22 theBear well, you already can... maybe you should use more words so i don't have to guess what you mean
09:22 Lamp for example, if i want the robot to sense an object i want it to be able to 'know' what object it is detecting
09:22 theBear orright, robot, there's a start... how does this robot 'see' ?
09:22 Lamp image sensor?
09:23 theBear when you say image sensor what do you refer to ?
09:23 Lamp like CCD or CMOs?
09:24 theBear orright, a camera
09:24 theBear specifically a video one
09:24 theBear so you're interested in object recognition software
09:24 Lamp yes
09:25 theBear maybe lookup openCV for a start, it's both a comprehensive and useful framework, and has a lot of related documentation, both general and specific
09:29 Lamp does it contain shape recognition modules?
09:30 theBear it includes everything you can imagine, just look at it
09:31 Lamp wow, thanks!
09:32 Lamp is there a page where I should start?
09:32 theBear i dunno, ask the wide wide world of web where opencv lives, and start there i guess
09:36 Lamp thanks for your help! I'm going to have a look at it. See you around
09:38 theBear heh, guess he doesn't have multitasking
09:38 theBear or even multiple tabs
11:40 GuShH theBear: multitasking? If he's still using a palm-pilot that's not a possibilty!
11:40 GuShH I'm so glad they're long gone.
11:40 GuShH pieces of shit, although they were the first "tablets"
11:40 GuShH or, among them.
11:40 GuShH now kids just get born and have a cellphone and shit. we only got SHIT when we were born!
11:40 GuShH damn these kids
14:04 GuShH RifRaf: hmm well your lathe costs 2x here, but we all know everything does...
14:04 GuShH why do I pay for premiums when I live in such a shitplace country? damn it
14:04 GuShH still, could be worse.
14:14 MrCurious could move...
14:14 eadthem would anyone else be concernd about a 7$ berring? http://www.vxb.com/page/bearings/PROD/Kit7358
14:15 Tom_itx their prices are going up soon
14:15 Tom_itx they sent me an email
14:15 eadthem ?
14:15 MrCurious ebay. buy chinese
14:16 Tom_itx those are chinese
14:16 MrCurious vxb is over the top priced any way
14:16 MrCurious no, direct from china via ebay
14:16 eadthem 7$ for a 1 inch shaft berring flange mount
14:16 MrCurious actually, that price seems rather reasonable
14:17 eadthem i would of expected it to cost more
14:17 Tom_itx send me $20 then and i'll send you one
14:17 MrCurious pricing error. order before they catch it
14:17 eadthem i mean more like mc master
14:17 MrCurious i could send you one for $80
14:17 eadthem at maby 40$ each
14:17 Tom_itx mcmaster aren't known for being cheap
14:18 eadthem no
14:18 eadthem there known for tearing off a arm to go with your legs
14:19 MrCurious mcmaster is for when you arent paying, or when you cant find it anywhere else
14:20 Tom_itx eadthem, what are you making with it?
14:21 eadthem ordering the bearings for the bandsaw, and the gears and stepper motor for the table saw fence
14:22 Tom_itx low rpm should be fine even with a cheap bearing
15:20 eadthem ya 200 pounds force is the only part thats even demanding
15:44 MrCurious its a little hot today
16:27 eadthem im trying to find a gear that will mesh well with 3/8 threaded rod 24TPI
16:30 Tom_itx sdp-si
16:30 eadthem ya not having any luck
16:30 Tom_itx not gonna be pointed like you want though
16:31 eadthem i need a 6 foot rack
16:31 Tom_itx you want a pinion style gear
16:31 Tom_itx i forget what the big one is called..
16:31 eadthem but the price of such a thing is more legs than im willing to give up
16:31 Tom_itx so make one
16:31 eadthem i was looking at worm gears (the gear the meshes with a worm
16:32 eadthem a diametrical pitch of 64 is .049" tooth spaceing
16:32 Tom_itx http://tom-itx.dyndns.org:81/~webpage/reprap/drive6.jpg
16:32 eadthem on its circumphrence
16:32 Tom_itx that was made with a tap
16:32 eadthem this is close to the rods .0416
16:32 eadthem tooth spaceing
16:33 eadthem ooo
16:33 Tom_itx figure the root diameter
16:33 eadthem spinning a tap with the metal on a pully
16:33 Tom_itx of the one you need
16:33 Tom_itx and it will come out even
16:33 Tom_itx i cheated
16:34 Tom_itx i figured the drill size for the tap, subtracted that from the gear diameter to get the root
16:34 Tom_itx but i'm not sure you can be precise with the number of teeth that way
16:35 Tom_itx i didn't care on that project
16:35 eadthem dont have to be
16:35 Tom_itx it was a pinch roller
16:35 MrCurious 11:30 am on a sunday, people come to the door selling bibles. does being home at that time not betray that we probably have all the bibles that we need...
16:35 robotustra hi Tom_itx
16:36 robotustra as soon as I understand you are guru here and in @avr channel?
16:36 Tom_itx 3/8 24 takes a Q drill which is a .332 diameter
16:37 Tom_itx robotustra, who want's to know?
16:37 MrCurious careful tom, looks like a trap...
16:37 Tom_itx it is
16:37 dthem wispers to tom, "
16:38 Tom_itx so take the .332 into account when you figure your pulley size
16:38 Tom_itx cut a round groove in it half that diameter etc
16:38 eadthem a 20 TPI is .05" tooth spaceing a 64 diametrical pitch wormgear is .049
16:38 eadthem that might work
16:38 eadthem only off by 1 thou
16:38 Tom_itx so you can figure your inner diameter from the .05 tooth spacing
16:39 Tom_itx and you know the groove size you need
16:39 MrCurious http://www.ebay.com/itm/10-pcs-Gear-Rack-0-5-modulus-Plastic-pinion-drive-rod-DIY-parts-/111089470766?pt=LH_DefaultDomain_0&hash=item19dd72cd2e
16:39 robotustra I
16:40 MrCurious or one with the gear :D http://www.ebay.com/itm/10-pcs-x-Gear-Rack-0-5-modulus-Plastic-rack-pinion-drive-rod-DIY-parts-/251205029427?pt=LH_DefaultDomain_0&hash=item3a7cfc8e33
16:40 eadthem 0.5 modulus teeth per what?
16:40 robotustra I'm kust looking a channel where people do android robots
16:40 robotustra *just
16:41 MrCurious i think you are there...
16:41 eadthem if you mean like data your there
16:41 eadthem if you mean like the cellphone keep looking :p
16:42 eadthem MrCurious, when they say .5 modulus that mean .5mm pitch?
16:42 MrCurious why am i searching for rack and pinions. do i need those?
16:42 Tom_itx it's my pinion you need a better rack
16:42 MrCurious sry, not an engineer. programmer. cant parse that even
16:42 GargantuaSauce i think this is a good opportunity to whine about how expensive ballscrews are
16:42 MrCurious but i bet googling for pitch and modulous could explain the relationship
16:43 Tom_itx GargantuaSauce, nobody cares
16:43 eadthem GargantuaSauce, try amazon
16:43 Tom_itx i want some too
16:43 GargantuaSauce maybe i don't care that you don't care
16:43 Tom_itx i don't care that you don't care that i don't care :)
16:43 GargantuaSauce well crap
16:44 eadthem mmm theres another way i could do this, i could run this setup like a leadscrew
16:44 eadthem then i wouldnt need to mesh anything but standard gears
16:44 Tom_itx belt drive
16:44 GargantuaSauce for 6 ffeet you probably want a timing belt yeah
16:45 eadthem mmm i was thinking a 8 foot shaft with a worm gear on each threaded rod and the worm on the shaft
16:45 MrCurious wait! we have gone off topic... werent we worshiping tom :P
16:45 eadthem less backlash over that distance
16:45 Tom_itx http://bell-everman.com/products/linear-positioning/servobelt-linear-sbl
16:45 Tom_itx that's just what you want
16:46 Tom_itx look at 'how it works'
16:46 eadthem ya the threaded rods move the tablesaw fence the fence is 8 foot long
16:48 eadthem http://www.mcmaster.com/WebParts/Content/CtlgPageWebPart/CtlgPageShell.aspx?ReqTyp=CATALOG&CtlgPgNbr=3138&CtlgEdition=119&partNbrLookUp=92580A209&viewporthgt=597&envrmgrcharsetind=2&ScreenWidth=1600&McMMainWidth=1516#
17:00 robotustra the only one guy who do android robots in here?
17:01 robotustra eadthem: link does not work
17:01 eadthem ya that sound about right for mc master
18:40 rue_more http://www.youtube.com/watch?v=4tG2bTOGxK0 linear positioning with a standard solinoid
18:50 GargantuaSauce how much current does it draw to hold it in the middle?
18:51 rue_more I didn't check the current draw
18:51 GargantuaSauce i guess a better question is what's the relation end up being between duty cycle and position once it's converged
18:52 GargantuaSauce is it linear-ish?
18:52 rue_more yea the spring has a linear inclreasing foce, and the solinoid is logrithmic responce
18:52 rue_more all current was under 2A
21:19 GargantuaSauce http://workman-industries.net/images/reprap/tri_1.jpg finally