#robotics Logs

May 19 2013

00:03 ace4016 causing the companies to be forced to abide
00:03 ace4016 (it cost them a lot of money to prove it wont)
00:04 RyanS I was reading a blog by a guy who custom-designed something from scratch and used a RoboteQ dual motor robot controller, but said it was a very real risk it could drive you into danger.. so he installed a kill switch
00:04 RyanS That obviously is not ideal if you can't reach for the kill switch
00:04 ace4016 i'm not sure if wheel chairs are regulated actually...
00:04 theBear indeed
00:05 theBear pretty sure even my walking stick has a standards sticker/number on it
00:05 ace4016 so you actually might have a chair that has a chance to run you into a pool, traffic, off a cliff, etc.
00:05 RyanS Wheelchairs don't have kill switches, so there must be failsafes in the electronics?
00:06 ace4016 but if the gubermints were smart, they'd attempt tp regulate it
00:06 theBear mmmm, gophers don't have much/anything in the way of failsafes (i've worked on them extensively, not wheelchairs so much) but maybe it's like x/y mains caps, the switches are designed to fail open if they fail
00:07 RyanS gopher ?
00:07 ace4016 i think those mobile chaits they have at grocery stores
00:07 theBear you know, like a err, whaddya callit, shoprider, old persons electric scooter thing
00:08 ace4016 in the US, they seem to primarily be used by obese and/or lazy people
00:08 theBear doesn't surprise me :)
00:08 ace4016 lol
00:08 theBear shoprider is a brand/series btw
00:08 theBear for those of you that don't regularly visit mobility stores
00:09 RyanS in terms of engineering it's a no-brainer to implement failsafes, to prevent a disastrous run away?
00:09 RyanS those 3 wheeled scooters are so dangerous
00:10 theBear i mean, it's easy to add killswitches and seat switches and various things, but if something is 'in working order' and someone leans on the controller, there's nothing to stop it going into a swimming pool or off a cliff or into a woodchipper....
00:11 RyanS no I'm not talking about leading on the controller but a total electronics failure
00:11 ace4016 RyanS, from an engineering sense, yes. from a business sense, it depends if the rate of failure is enough to make the investment into putting the failsafe worth it compared to just paying out money when sued
00:11 ace4016 it's a sad thing to have to recognize, but business sense takes precidence over engineering sense
00:12 RyanS You can't even move this thing with the battery charger connected
00:13 RyanS It beeps at me if the brakes (which are clutches but they call them brakes ) are off
00:14 RyanS this one has too many failsafes, lol
00:15 RyanS So what do you think, brushless DC motors and lithium polymer batteries? or something more exotic?
00:17 theBear those modern rc brushless motors are pretty unbelievable, sounds exotic enough to me
00:17 theBear i mean, brushless 'jet' engines, outta control !
00:17 RyanS Gas turbine engine with AC and generator and AC motors? Like a train
00:18 theBear heh, that'd be some fancy-ass wheelchair
00:18 theBear but the rc ones are really just brushless turbine kinda engines
00:18 theBear ridiculously lightweight fast powerful ones
00:18 theBear the rc-sized actual jet engines are pretty special in my opinion tho
00:19 RyanS they have turboprop radio controls too
00:19 theBear years ago a local guy built a i dunno, 747 or something like that, maybe 4 or 5 meter wingspan from memory, jets and all, out of control !
00:19 theBear this was the 'olden days', way before brushless
00:20 RyanS Turboprop engine start-up sounds make me want to cream my pants
00:20 theBear probably more like 3 or 4... i was smaller then :)
00:22 haryv bear, see the video of a guy who had 10 of those mirco jets attacked to a pack, and hovered for 10 minites?
00:22 RyanS http://www.youtube.com/watch?v=gROutaMsyCw
00:22 RyanS R/C pc-7
00:26 theBear i don't think i did
00:27 RyanS http://www.youtube.com/watch?v=Tp1UW0eDYY0 scratch built turboprop!!
00:31 theBear that's pretty cool, but it hurts my ears :)
00:31 RyanS How on earth would you build a turbine fan on hobby machine tools...
00:31 theBear i think the kids call it 'mad skillz' <grin>
00:32 theBear wow, the sun is real skinny and quick moving in the 'backyard' this time of year
00:33 RyanS i miss summer
00:33 theBear don't worry, it'll come back sooner or later
00:38 RyanS ummmmm that turboprop radio control aircraft.... The motor is $5000
04:32 rue_house goodnight internet
06:18 theBear goodnight rue :)
19:43 MrCurious new rule, when picking up piece(s) of a broken glass, use 2 hands, especially when the glass is wet.
19:44 MrCurious and always have a magic word ready in mind for when you fail this new rule.
19:44 theBear like "tada" or "shazam !" ?
19:44 rue_shop3 or "F***"
19:44 rue_shop3 ?
19:44 MrCurious the latter
19:45 MrCurious got a good 2cm cut across the thumb pad of my palm
19:45 theBear i've never heard a magician say that when he pulls a rabit out of a hat :)
19:45 rue_shop3 would if it bit him
19:46 theBear rabbits bite ?
19:46 theBear i haven't had close contact with them since i was a kid
19:46 MrCurious vorpal bunnies do...
19:47 MrCurious or is it vorple
19:47 theBear i dunno, but it gives me hazy recollections of something to do with vampires
19:47 rue_shop3 any animal can bite
19:48 Tom_itx even you
19:49 MrCurious thats what she said?
19:51 theBear yeah, but apparently it's nice when i do it :)
19:51 theBear if i really wanna hurt someone i just swing my giant furry arms gently then watch them fly across the room, kungfu movie style :)
19:52 theBear all legs and arms trailing behind them like there's an invisible battering ram in their chest :)
19:53 MrCurious you have bear arms?
19:53 MrCurious i heard that was a right
19:53 theBear yup, and i exercise it :)
19:54 theBear sometimes in public i sprinkle alcahol over them and set them alight too, but it's cool, they're legal fire arms :)
19:54 theBear heh, and far from concealed
20:00 MrCurious heh
22:49 MrCurious wife says "dont call me sudo!"
22:49 orlok you need sudocream!
22:58 theBear sudo make me a sammich !
22:59 MrCurious who is this sudo, is she your lover!
22:59 orlok http://www.sudocrem.com/australia/home.php
22:59 orlok Its expensive, white, and coats TV's
23:00 theBear rofl sudocreme
23:01 MrCurious sudocream wile my as#!
23:02 theBear hmmm, does that make conditional programming while'ing away the time ?
23:33 shuggans rue/rif - have the tank here FINALLY
23:34 shuggans http://visuafusion.com/Robotics/IMAG1819.jpg -http://visuafusion.com/Robotics/IMAG1820.jpg
23:36 MrCurious you built that?
23:36 shuggans My brother doing the mechanical
23:36 MrCurious is that a differential?
23:37 shuggans me the electrical / robotic / programming
23:37 MrCurious so tread with traction will or wont get all the power
23:37 shuggans he built what you see so far
23:38 MrCurious trying to work out how it turns with that 2nd pic orange gear box
23:38 orlok i redid my perfboard layour over the weekend
23:38 shuggans going to be sprockets off the motors onto the axles by the differentials to drive the motors
23:38 orlok and managed to cram it all in a tiny area, and avoided the use of any wires on the top side
23:38 MrCurious so the treads can go in different directions, or one at a time
23:38 MrCurious as teh differential i think serves to sync them
23:39 orlok MrCurious: nice, not going for two seperate motors though? you going to stick with a single chain too?
23:39 MrCurious what will you use for tank treads? wood slats, runner on wood, plastic plastic with rubber metal?
23:39 shuggans motors will drive independantly (either foward or reverse, when turning one iwll aid the other the other if driving foward by pulling its side everse
23:39 shuggans revers*)
23:40 MrCurious wouldl have to have 2 motors, or some extra wheels, to steer
23:40 orlok ahh, so two motors.. why have a diff then?
23:40 orlok shuggans: skid steering is the common term
23:40 shuggans not sure why he has a diff
23:40 orlok yeah
23:41 orlok unless.. one way it could work, is single motor, feeding into diff
23:41 orlok and then you somehow have a break on each track
23:41 orlok brake
23:41 shuggans I think he has a reason.
23:41 shuggans the motors have built in breaks
23:41 shuggans brakes*
23:41 orlok so if you dont want one track to turn, apply brake
23:42 orlok differential only makes sense for a single motor driving two wheels
23:43 MrCurious probably be fine if you pluck the 2 gears from inside teh diff out, seperating the 2 axels
23:43 shuggans I can roll it foward/back
23:43 shuggans and the whoel thing rolls
23:43 MrCurious other than that issue, looks real promising... i want to see this when its more polished!
23:43 shuggans when rolling each the opposite, the diff kicks in
23:44 shuggans no clue how he did that...
23:44 shuggans O.O
23:44 orlok thats what they do.. but is there any input to the differential?
23:44 shuggans lol. He's the mechanic/fabricator in the family (from our generation)
23:44 orlok shuggans: have you seen the 60's "differentials explained" clip?
23:45 MrCurious great youtube clip!
23:45 orlok oh
23:45 orlok 1930's even
23:45 orlok http://www.youtube.com/watch?v=K4JhruinbWc
23:45 MrCurious explained the diff, why we have it, how it works..
23:46 shuggans no, there will just be sprockets straight on the motor with a chain straight foward to another sprocket on the axle (on each side)
23:46 MrCurious are you planning on arming it?
23:46 shuggans yep.
23:46 MrCurious or thought about sensor packages or processing power
23:46 shuggans .223 SAIGA
23:46 shuggans I have a mini PC which I wrote a server application to run on
23:47 MrCurious guessing you or a family/friend is in the mil and deployed, and in need of a extra-life...
23:47 shuggans which is waiting on a network port (goign to run it on mobile broadband 3g or 4g) and then the program sends commands received from the controller application (controller pc remotely through the internet) to an arduino via serial port
23:47 MrCurious that should be the name used for combat robots... "the extra life"
23:48 shuggans I have all of that working
23:48 shuggans rue helped me design some motor driver boards
23:48 shuggans (Which Im thinking of revisiting now that i have the tank in front of me and see the spacing I have to work with)
23:48 MrCurious done any battery run time testing? how long can it stay in motion and computing before the battery goes flat
23:49 shuggans he jsut delivered the tan ktoday - lives 3 horus away.
23:49 shuggans I have my program etc working with a small motor driver board
23:50 shuggans Just need to build out my driver system now, mount the arduino and pc etc
23:50 Jak_o_Android Time to Start assembling the hell-bridge
23:50 shuggans it's gna be badass when it's done - Im pretty stoked
23:54 MrCurious still cant get over thinking it would only take 2 months to learn robotics and make a cool robot
23:54 MrCurious (2 years ago)
23:54 shuggans I havnt doen battery testing etc - need a power inverter for the pc
23:54 shuggans :P
23:54 shuggans Rue taught me alot in two months
23:55 shuggans I can mak a motor driver and understand different concepts etc
23:55 shuggans no expert by any means
23:55 shuggans but I can make this tank! :)
23:56 MrCurious you can opt for ARM based computer board if you want a leaner power system
23:56 MrCurious like a beagle bone black.
23:56 MrCurious or an odroid u2
23:58 shuggans (Im a .net developer)
23:58 shuggans need windows OS + .net 3.5 to run my server app
23:59 orlok *barf*
23:59 orlok :)
23:59 shuggans haha
23:59 shuggans I know - I know.
23:59 shuggans I need to learn C++ or java.
23:59 shuggans on the to-do list.
23:59 orlok or python