#robotics Logs

May 18 2013

11:57 Lola8088 Knit sleeves for air muscles... would look cute, no?
13:30 rue_bed ni think it has to be a cross weave
13:31 theBear stupid weather ! i want clean clothes
13:31 rue_bed its still in rinse?
13:32 theBear nah, last round it wasn't great weather and a few things went smelly drying, so i ain't risked it yet
13:49 Lola8088 not in place of cross hatch... ontop of.
13:49 theBear like a teacosy :)
13:50 MrCurious got a pair of 5v dc-dc converters, and they are epoxy sealed. wonder if that makes them better or worse at heat venting
13:50 theBear probably slightly worse, but more reliable in other ways
13:50 rue_bed like when zhanx steps on it
13:50 rue_bed might be ok
13:51 theBear i wonder how epoxy compares to air tho, have to be slightly more temp conductive i would think
13:51 theBear whaddya all know about beans ? i'm getting very close to the last food in the house and i don't wanna screw this up
13:51 MrCurious my non sealed ones get hot, but if i blow a breath or two on them they are completely cool
13:52 theBear sounds like i put the beans and bean juice in a pot, heat it up a bit but don't simmer it, add some salt just as they stop being hard
13:52 theBear what are you, jack frost ?
13:52 MrCurious you been talking to my wife?
13:52 theBear heh
13:52 theBear doh ! i shoulda said something about beans there
13:52 theBear opportunity wasted !
13:53 theBear so hungry ! someone give me confidence to cook beans
13:53 MrCurious think of the musical implications down the road
13:53 theBear i'm seriously starving, i'll take the risk
13:53 MrCurious got a car
13:54 MrCurious there are places that sell ready to consume food
13:54 theBear i think at this point anything i eat will be completely absorbed anyway
13:54 theBear yeah, they sell it if you got more than a dollar
13:54 theBear i, have less than that
13:54 theBear and no car
13:54 theBear but 3 skateboards and 2 pushbikes, but that doesn't help
13:55 MrCurious so beans and rammon noodles
13:55 rue_bed theBear, you must be able to find some work
13:55 MrCurious got rice to add to that
13:55 MrCurious maybe some soy or sirachie sauce
13:55 rue_bed something you can do dispite
13:56 theBear no i don't ! asshole i gave a place to stay took all the rice and all kinds of stuff i kept for times like this
13:56 theBear i think i still got soy
13:56 rue_bed call answering service?
13:57 theBear rue_bed, i can't guarantee if i'll be able to walk to the kitchen any given day right now, you can't in good faith get work like that
13:57 MrCurious have care.... its best to filter your soy through food. do not attempt to inhale it directly and unfiltered
13:57 rue_bed from home
13:57 theBear meh, i like it, it's like white mans msg (salt) in liquid form
13:57 rue_bed your up all night aren't you?
13:57 theBear rue_bed, everything i come up with so far you still gotta be able to guarantee some kind of hours
13:57 theBear i am right now
13:57 theBear but that's only cos i can't sleep
13:57 MrCurious suppose you could game the system. look up some names of strangers creep their facebook, then knock on teh door, and insist you are old friends
13:57 MrCurious chit chat, know things, and play it for a meal
13:57 MrCurious and possibly a new friend
13:58 theBear huh ? i'd rather starve than go near a facebook
13:58 theBear i AM good at confidence/acting these days tho
14:00 rue_bed I think you could prolly be answering service for about 3 businesses at once with one line, that should bring in almost $100/mo
14:00 rue_bed is voip available there?
14:00 rue_bed get a headset...
14:00 theBear maybe, i have limited tolerance for patronising customers
14:00 rue_bed most businesses that are looking for that might only get about 4 or 5 calls a week
14:01 theBear course it is, my 'landline' has been remote end voip for years now
14:01 theBear but see, they need you to guarantee you can answer that line at given times, i can't do that
14:01 rue_bed do they give you 'multi-line' with voip up there?
14:01 rue_bed your up all night, you like that dont ya?
14:01 theBear well, you can get it, and of course there are pro services like paid skype with local numbers etc etc
14:02 theBear yeah, but sometimes i'm rolling around in pain unable to talk
14:02 rue_bed ah
14:02 rue_bed damn
14:02 theBear totally
14:02 rue_bed didn't they do surgery on ya?
14:03 theBear nup, no current surgery is expected to help
14:03 rue_bed its not tho?
14:03 theBear medically i'm pretty screwed
14:03 rue_bed I'm getting outa bed..
14:03 MrCurious dont do it
14:03 MrCurious its dangerous out there
14:03 MrCurious send a probe instead
14:04 rue_house I need food and shower
14:07 MrCurious i need a floating couch and a robot to bring me soda
14:07 rue_house fill the room with mercury, the couch will float great
14:07 rue_house but there might be side effects
14:08 MrCurious guessing if i am swimming in Hg, i wont really care about the side effects
14:08 GargantuaSauce it would conduct all the heat out of you and you'd die of hypothermia
14:09 GargantuaSauce and it would be awesome
14:09 MrCurious i like that phrase "creatively accident prone"
14:10 MrCurious imagine the best part is that its a preservative. i would no longer age
22:24 RyanS so the psychology bit, are we talking about human psychology or as it pertains to robots/artificial intelligence?
22:27 theBear huh ? how far back i gotta go to see us talking about this ?
22:28 RyanS Just read the topic :)
22:29 RyanS "Mechanical Electrical Programing and Psychology"
22:29 theBear ahh, i miss the left side when it's longer than my screen
22:33 RyanS Have you seen this robotic arm modelled on an elephant trunk? It's a prototype by that motion control company Festo
22:33 RyanS pretty cool
22:34 theBear i have not, and when you say motion control company, you don't mean powertool company ?
22:36 RyanS nope, Festool is the tool company which I think is a subsidairy unless of course they sold it off
22:37 RyanS http://www.festo.com/cms/en_corp/9655_10217.htm#id_10217
22:37 theBear fairy nuff
22:38 theBear wow, a robot trunk
22:38 theBear pneumatic eh
22:38 eBear thinks back to
22:38 theBear ahh, air
22:38 RyanS I don't know whether this is genuinely research into technology they plan to make into products
22:39 RyanS I guess it also has a marketing component 'these are our capabilities'
22:40 RyanS How about pneumatic 'muscles'.. I would have thought they'd be too unpredictable?
22:42 theBear rue is the guy to talk to about air muscles, usually pneumatic suggests more piston kinda things tho, which are very predictable, so long as you 'know' that air is compressible
22:42 theBear and of course the piston/tube sizes/volumes etc
22:44 RyanS I have only read that if you want speed = pneumatics, high force = hydrulics
22:45 theBear makes sense as a broad kinda rule i suppose, i tend to think that air/gases compress, liquids don't (much), therefore you get a springy/shock absorber effect with pneumatics, at least non-compressed/forced ones, and a more solid feel with hydraulics
22:48 RyanS I have been having a lot of problems with a electromechanical actuator on my wheelchair. but the manufacturers aren't interested, and the supplier can only replace it with the 'genuine' part. 'Linak' is the brand of actuator and they seem to make a lot of plastic crap
22:53 theBear you mean the joystick thinger you were talking about a while back ? or some kinda clutch/engagey thinger ?
22:54 RyanS nah.. this: http://www.linak.com/corporate/pdf/ENGLISH/DATA%20SHEET/Linear%20Actuator_LA31T_Data%20Sheet_Eng.pdf
22:54 theBear oh, linear actuator, i know what they, rif made one years ago
22:55 RyanS I think I use it a lot more than the designers of the wheelchair manufacturer anticipated
22:55 RyanS It's been replaced five times within two years
22:55 theBear mmm, you working on replacement not 'upgrading' the current one i guess ?
22:56 RyanS well because repairs go through the Department of human services you can't just request a different part.. It has to be replaced with the same part
22:57 theBear oh, mmm
22:57 theBear how does it fail ?
22:58 RyanS so I want to find an 'industrial grade' actuator (which I will have to purchase myself)
22:58 theBear mmmm... linear actuator is definately the keywods
22:58 theBear keyword
22:59 RyanS I'm not entirely sure how it fails but it jams in the push stroke (which is going against gravity in this situation)
23:00 theBear yeah, that'd make sense, attached to the bottom of the seat i gather ?
23:00 RyanS the pull stroke still moves
23:00 RyanS yes if you got a chair and tilted the entire thing backwards that's what it does
23:06 RyanS I don't know how true it is but wheelchairs are like 'design by committe'. They seek input from healthcare professionals who have no fucking idea about engineering
23:06 RyanS And you end up with poorly designed crap
23:09 RyanS Here you go http://www.pridemobility.com/quantum/seating/tru_balance_2_power_positioning/hd_tilt.asp
23:09 theBear yeah, like a lot of stuff these days :( not to mention the politics of bidding for contracts to supply the parts etc, it's all largely independant of the actual product and its needs
23:10 RyanS It hinges at the back and there are guide rails
23:11 RyanS but the actuator appears to be holding the entire load up
23:11 theBear ahh, i remember ones like that
23:11 theBear heh, it does indeed
23:11 RyanS Is that actually bad design?
23:11 theBear tho in theory those kinda actuators can be very strong, they're generally built like an integrated wormgear
23:11 theBear all depends how strong the actuator is
23:12 RyanS Right, do you think it matters whether it's ACME or ball screw
23:13 Tom_itx ball screw is smoother
23:13 theBear and probably more durable under heavy load
23:13 RyanS So if you use something all the time you was a higher duty cycle and probably ballscrews would be better?
23:14 theBear it's kinda like bushes vs ballbearings in a motor, the ballbearings are just 'better'
23:15 RyanS hmm, when it fails you can hear the motor spinning but the piston is stuck
23:16 RyanS The motion is 90� relative to the lead screw
23:16 theBear mmm, sounds like the actuatey bit/gear is stripping, little bit stripped it'll move with no load/some help from gravity, but won't be able to push too hard
23:17 RyanS There is and large plastic gear
23:18 RyanS the bevel or worm gear?
23:19 RyanS I have only briefly seen inside however I don't think it's a worm
23:20 theBear usually/often those things work with a driven thread and a nut/ballscrew style thing attached to the moving element, kinda like an integral worm
23:20 theBear pretty sure rif made his with some threaded/booker rod and a nut, like a diy cnc drive
23:22 RyanS Are you talking about the 'gearbox' that connects the output shaft of the motor at 90� to the driven end of the lead screw?
23:24 theBear i'm talking about the leadscrew
23:24 RyanS Linak is a brand that you see everywhere in healthcare equipment but apart from 2-3 models I fail to see how then can be used for industrial machinery
23:24 theBear they're like a worm except instead of turning a gear it moves the ballscrew thingy linearly
23:24 RyanS hmm I don't think the leadscrew is the problem
23:25 RyanS I think it's somewhere between the motor output shaft and the driven end of the lead screw
23:27 RyanS I can't see the local linak distributor telling me the shortfalls of their products.....
23:27 theBear nah, but the ratings/specs should give you a good idea, and if you can identify plastic/metal gears well, metal is always gonna last longer, specially under any kind of load
23:30 RyanS what about worm drive versus bevel gears? (timing belts seem to be only an option where the motor is parallel to the piston & leadscrew) In terms of durability
23:32 theBear mmm, deep bevel gears are damned strong, worm is very strong on the drive side but i would think tends to wear at the other gear, or at least you need nice slippy lubrication and not to let it ever go dry
23:38 RyanS hmm I use a lot of small travel, push/pull, repetitious movements of the actuator. I don't know should I be looking for a higher duty cycle actuator?
23:39 RyanS this model is "Duty cycle: Max. 10% or 2 minutes continuous use followed by 18 minutes not in use"
23:46 Tom_itx linear stepper
23:47 RyanS it needs to interface with existing electronics
23:48 RyanS I think it's just a plain old DC motor with limit switches
23:51 RyanS I need to get rich, hire a team of engineers and design myself a vehicle from the ground up
23:53 ace4016 heh
23:53 RyanS composites, titanium, lithium batteries
23:53 ace4016 i have a desire to design a car from the ground up
23:53 RyanS yeh but there is already plenty of cars to choose from on the market
23:54 ace4016 none that ooze engineering though
23:54 RyanS And car manufacturers actually innovate (sometimes)
23:54 ace4016 rarely
23:55 RyanS same as wheelchair manufacturers then
23:57 RyanS What do you suppose is used as a failsafe to prevent the motors going berserk and propelling me into a pool?
23:58 RyanS Traffic
23:58 RyanS Cliff