#robotics Logs

May 18 2015

02:49 deshipu veverak: also https://www.youtube.com/watch?v=54kZbPzlTI8
03:52 veverak thanks a lot!
06:25 veverak deshipu: hmm, interesting
06:25 veverak specially the first one
06:26 deshipu it's from the "robotic vision" course
06:26 deshipu the course is pretty basic, though
06:27 verak finally put together doc about his
06:27 veverak 1000 chars tho
08:01 veverak https://scontent-ams.xx.fbcdn.net/hphotos-xft1/v/t34.0-12/11273432_1010670372277681_1789268099_n.jpg?oh=44e3f152573ac68bbdff0d4b76502127&oe=555BE077
08:01 veverak robot done!
08:01 veverak :)
08:02 deshipu looks slightly different than the openscad renders
08:02 deshipu can it navigate?
08:02 veverak nah, just attached electronics on old rc chassis
08:02 veverak ...
08:02 veverak deshipu: not yet
08:02 veverak finishing electronics
08:02 veverak or... basic electronics
08:03 deshipu an h bridge?
08:03 veverak not
08:03 veverak actually, I can lend raspberry pi with camera form hackerspace
08:03 veverak so I just need 5V for it
08:03 veverak (battery got 7.4V and it's lipo, so I will propably buy proper UBEC thingie)
08:04 deshipu how are you going to control the motors from the pi?
08:04 veverak pwm
08:04 veverak deshipu: whcih motors?
08:04 veverak there is only one
08:04 veverak :)
08:04 deshipu well, one is enough, you still need to control it
08:04 deshipu and pi won't be able to provide the power
08:05 veverak I use traditional RC electronics
08:05 veverak means, 10.5T brushless motor with proper ESC controler and 1:7 gearbox
08:05 deshipu so, PPA?
08:05 veverak it's racing motor for onroad models... so it have to be geared
08:06 veverak car would fly otherwise
08:06 veverak deshipu: esc is controled by PWM
08:06 veverak http://www.losi.com/Products/Default.aspx?ProdID=LOSB9554
08:06 deshipu ok, cool, what are you using to bit-bang the pwm on the pi?
08:06 deshipu because it doesn't have hardware pwm, mind you
08:07 veverak arduino so far
08:07 veverak firmwata inside
08:08 deshipu ah, so you have a piece of everything in there :)
08:08 veverak more or less
08:08 veverak "prototype"
08:08 veverak :)
08:09 veverak deshipu: it's easiest way to get something and try it
08:09 veverak lately I can use smaller arduino... just raspberry... or whatever will seem nice
08:10 deshipu sure
08:10 deshipu looks good
08:10 deshipu is that a gimbal in the front?
08:10 veverak it will be gimbail
08:10 veverak and it's actually in the rear
08:10 veverak :D
08:10 deshipu why?
08:11 veverak better position
08:11 veverak you see front wheels clearly
08:11 veverak so you can fit in tight space when you drive it wireleslly
08:12 veverak deshipu: and one of the servos that was there was useless, so had to replace it
08:14 deshipu I have one of those hexbug hexapods
08:14 deshipu a large one
08:14 deshipu I'm thinking about puttin an rpi with a camera on it
08:15 veverak yeah
08:15 veverak I started to like rpi A?
08:15 veverak it is?
08:15 veverak but it's sad that it got just one USB and no wifi
08:16 deshipu you can always add a hub
08:16 deshipu and a usb wifi dongle
08:17 deshipu I need to get some A+s
08:17 veverak yeah
08:17 veverak but.... why? :D
08:17 veverak I don't like mindlessly adding stuff into it
08:17 veverak new b+ of course looks awesome
11:38 rue_bed and so we see a new type of consumerism, rpi being disposed of unused because the new model came out before the project was started
11:38 verak never had
11:39 veverak cubieboard!
11:39 veverak :D
11:43 rue_bed I did throw out all my PIC stuff when microchip switched from the 16F877 to the completely non-compatable 16F877A and required a closed source programmer that had to be bought from microchip
11:44 veverak lol
12:16 deshipu rue_bed: rpi is at least mostly compatible
12:17 deshipu rue_bed: also, I fried my B
12:33 veverak killer!
13:41 rue_shop3 hmm
13:41 rue_shop3 need a good object for transforming data from the control arm to the robot arm
13:41 rue_shop3 I think what I need is a standard definition for a set of positions
13:43 rue_shop3 controller,
13:44 rue_shop3 polling and data collector
13:44 rue_shop3 input transforms
13:44 rue_shop3 standard position set from input controller
13:44 rue_shop3 input to output transfroms
13:44 rue_shop3 standard position set for ouput device
13:44 rue_shop3 robot arm transforms
13:45 rue_shop3 spooler
13:45 rue_shop3 robot arm
14:26 verak draw today schematic for his program for r
14:26 veverak nice schematic
14:32 rue_house thats pretty good, I wrote a whole axis transformation class before the pot of water for my lunch boiled dry
14:50 Hyratel1 can anyone suggest a source for brass Fillister cap 1/4-20 x 1" with 5/8" smooth shank machine screws?
14:55 veverak ideally
14:55 veverak I should be able to restart each part of my robot
18:39 Mister anyone have some goos suggestions for hardware?
18:40 Mister making a gyrostabilised wheel..
18:40 Mister need an IMU
18:40 Mister and a breakoutboard
18:40 Mister and motors
18:41 Mister and powersuply xD
18:41 Mister power supply*
19:04 Hyratel1 anyone know a good source for 20 degree white LED spot modules of 70-150 lm ?
19:04 Hyratel1 20 degree spot-beam
19:23 SpeedEvil cutter.com.au
19:33 Mister guys.. i'm wondering something
19:33 Mister does normal electric bicycles use 5volt for the control circuit?
19:34 Mister is there any reason why this cotnroller can't do in reverse?
19:34 Hyratel1 most likely yes
19:34 Mister http://www.conhismotor.com/ProductShow.asp?id=111
19:34 Mister hmm, cool
19:35 Mister so it should be possible to put the control wires into an arduino and control the speed+
19:35 Mister ?
19:35 Hyratel1 use a voltmeter first
19:35 Mister aha good idea! =)
19:35 Mister i honestly didn't think of that..
19:36 Hyratel1 what's this going onto?
19:36 Hyratel1 electric scooter?
19:36 Hyratel1 3 phase...
19:36 Hyratel1 there should not be any reason
19:36 Hyratel1 why it can't do reverse
19:36 Mister trying to make a gyro stabilized vehivle
19:37 Hyratel1 with rider?
19:37 Mister nah just a small one
19:37 Mister to test
19:37 Mister a big small robot xD
19:37 Hyratel1 then you want a hobby RC brushless motor driver
19:37 Hyratel1 what's your motor
19:38 Mister http://www.conhismotor.com/ProductShow.asp?id=373
19:38 Mister cheapest i found atleast
19:38 Mister it's a budget robot :P
19:39 Mister with wooden structure
19:40 Mister that motor should be able to go in reverse, right? just by changing polarity?
19:40 Hyratel1 how big a robot?
19:40 Mister uhm
19:40 Mister it's a prototype
19:41 Mister think 1.5 meters tall or something
19:42 Hyratel1 what battery voltage
19:42 Mister Hyratel1: u can see a concept drawing of it on http://tundra-telebotics.com/
19:42 Mister hmm thinking of 24v.. just a cheap battery too
19:42 Hyratel1 are you trying to run before you walk?
19:43 Mister that is something i am wondering aswell... guess i can only find out by trying
19:44 Hyratel1 have you ever built a 4-wheeled robot?
19:44 Mister programmed the motors or made the shell? or both?
19:44 Hyratel1 from the ground up
19:44 Mister not anything that some1 earns money on..
19:45 Hyratel1 because I remember you being in here a while ago
19:45 Hyratel1 so?
19:45 Mister yeah, was looking for hardware brands =)
19:45 Mister now i hae money to buy
19:45 Mister have*
19:45 Hyratel1 if you don't ahve a grasp on the basic finctions of driving, I can't expect you to have a grasp of more complex topics
19:47 Mister i believe i have a fairly strong grasp of that subject, my vaocabulary is another case, however...
19:47 Mister vocabulary*
19:47 Hyratel1 also you write with things like 'some1"
19:48 Mister it's not really that much about driving with wheels tho, trying to make a really flat rocket engine that also can be controlled the same way
19:49 Mister hehe, i learned english from world of warcraft..
19:49 Hyratel1 I know brushless is in all useful ways superior but here, brushed is the way to go because design simplcity
19:49 Hyratel1 http://www.andymark.com/Default.asp
19:50 Mister aha, and brushed is 2phase?
19:50 Hyratel1 no
19:50 Hyratel1 brushed is DC
19:51 Hyratel1 brushless is 3-phase
19:51 Mister oh i thought dc was usualy 2 phase
19:51 Hyratel1 what
19:52 Hyratel1 where do you get that
19:52 Hyratel1 ok time to stop and do a vocabulary purge
19:52 Mister uhm, i read about electric motor a very long time ago xD
19:52 Hyratel1 time to review it
19:53 Mister can you help me out with that? xD why is it called a brushless motor? does the brush change the polarity?
19:54 Mister or is that done with another magnet these days?
19:54 Mister since the magnets are molded onto the chassis
19:58 Hyratel1 a brushed motor has a commutator that changes the mangnetic field in the rotor
19:59 Hyratel1 you know what, search youtube for "how a brushed motor works'
19:59 Hyratel1 and 'how a brushless motor works"?
19:59 Mister ops.. *thoguth brushed was usualy 2phase
19:59 Hyratel1 WHAT DO YOU MEAN BY THAT
20:00 Mister never mind.. >.<
20:00 Mister i thought the brush was that thing that changes the polarity
20:01 Mister and it is..
20:02 Hyratel1 it changes the polarity yes
20:02 Hyratel1 but most motors don't have only 2 contacts
20:02 Hyratel1 they ahve a LOT of them
20:03 Hyratel1 and the angle from the contacts/brushes to the lead angle between the active winding and the stator magnet is where it derives the torque from
20:03 Hyratel1 say you have a motor with ... 16 contacts
20:03 Hyratel1 that's 8 sets of rotor windings
20:04 Hyratel1 the active winding will be between 30-45 degrees away from the stator magnets
20:04 Hyratel1 but as the rotor turns, the active winding gets closer to the magnet and is turned off, while the next behind it turns on
20:06 Mister a pulse motor =)
20:06 Hyratel1 ???
20:07 Hyratel1 stop making up words
20:07 Hyratel1 terms
20:07 Mister i didn't invent that name >.<
20:07 Hyratel1 "pulse motor'
20:10 Mister instead of exposing a magnet to another constant magnetic field
20:10 Mister you use a pules
20:10 Mister pulse*
20:10 Hyratel1 there's ...
20:10 Hyratel1 no motor that doesn't do that
20:11 Mister a dc motor has to change the field
20:11 Mister so it's not constant
20:11 Hyratel1 any motor has to change the feild
20:11 Mister or it can have a constant field and a mechanical way to turn the magnet relative to the driveshaft
20:12 Hyratel1 you're missing the point
20:12 Hyratel1 actively
20:14 Mister uhm, i'm mixing up alot atleast..
20:14 Mister there is a difference between the perendev motor and a normal pulse motor
20:15 Mister perendev doesn't need to change it's polarity but most other motors do
20:16 Mister you can have electromagnets on the outside of perendev and make it electric
20:18 Mister i just made an understanding a very long time ago that pulse motors need 2 phases, and perendev can use anything but one needs a freequencytransformer
20:19 Mister it works in my head but i guess it's wrong lol
20:24 Mister aha
20:25 Mister i thought brushless motors where like the perendev motor
20:25 Mister is that wrong?
20:25 Mister https://www.youtube.com/watch?v=FxReArGbE_s
22:21 robotustra_ old silent friend in here
22:30 adam789654123 hello
22:31 robotustra_ hi
22:31 robotustra_ non robot maker
22:34 adam789654123 well.... im interested in the subject
22:34 adam789654123 i think id start out with paper automata though
22:35 adam789654123 robotustra_: what kind of robot are you making?
22:45 robotustra_ http://i.imgur.com/mDADfj3.jpg
22:49 adam789654123 robotustra_: a robot head?
22:50 robotustra_ I started from head yes
22:50 adam789654123 what does it do?
22:50 robotustra_ just watching a little bit
22:51 adam789654123 can the head look around?
22:52 robotustra_ you that no - there is no muscles on the neck yet
22:52 robotustra_ but it will be
22:53 adam789654123 cool
22:53 robotustra_ next stage to do arms
22:55 adam789654123 what will they be made of?
22:56 robotustra_ PLA, carbon fiber tubes I guess
22:57 robotustra_ some metal
22:57 robotustra_ aluminium
23:00 robotustra_ I have to think a little bit about joints, but in general I know how they will look like
23:00 adam789654123 cool
23:01 adam789654123 im heading off
23:01 adam789654123 cya
23:01 robotustra_ bye
23:01 adam789654123 bye