#robotics Logs

Jan 05 2015

02:08 GuShH not a big worry since I've got other, better chucks... but goes to show cheap is cheap.
02:19 rue_house its just when I overtighten mine
02:19 rue_house the jaws land on square on the bit, as you crank is they start to move away at the top
02:19 rue_house tip
05:24 GuShH rue_house: that doesn't happen on the real jacobs, just the knockoff and low duty chucks
05:24 GuShH they get bell mouthed very easily
05:25 GuShH there's a reason heavy duty chucks are expensive :p
05:25 GuShH compared to the low end stuff, they weigh twice as much and last probably 10 times longer
05:25 GuShH even the key is better
05:25 GuShH usually longer so you don't have to stress your hand as much
05:26 GuShH just things you notice :p
05:26 GuShH (I extended the key on the cheap chuck with a chunk of aluminum tubing)
05:26 GuShH of course if you don't go by feel you can easily overtighten it then
11:42 GuShH rue_house: here's the die head I talked about, forgot to take a pic earlier http://i.imgur.com/0VEJBbC.jpg
11:43 GuShH this was the first test, my OD was low (as was the tool heigh when I faced it heh) but worked fine for a test http://i.imgur.com/LxrTyCx.jpg
11:43 GuShH I had to replace the release springs since they were too stiff and it was stripping the threads before the head could open!
18:59 codepython777 is there a 4WD mobile robotic platform that one can control using usb or i2c (preferably < $500)?
19:00 Hyratel https://dl.dropboxusercontent.com/u/33593534/images/Robot/DSCN2011-1k2.jpg
19:00 Hyratel codepython777,
19:01 Tom_itx not until you make one
19:01 Hyratel http://www.andymark.com/AM14U2-p/am-14u2.htm
19:02 Tom_itx i bet that exceeds $500
19:02 Tom_itx by quite a bit
19:02 codepython777 http://www.robotshop.com/en/4wd-hercules-mobile-robotic-platform.html#productsReviewBoxTitle - how does one control something like this with a i2c?
19:03 Tom_itx why I2C?
19:03 Hyratel I don't think you're understanding the difference between Motor Controller and System Controller
19:04 Hyratel motor controllers can be considered a type of amplifier
19:06 Hyratel https://www.sparkfun.com/products/13141
19:06 Hyratel this has no motor controllers
19:06 Hyratel you'll need to buy and equip them
19:08 Hyratel codepython777, what's your control source input?
19:08 codepython777 Hyratel: I've a raspberry pi, that i want to use to control a 4WD platform. The pi will be sitting on the platform.
19:08 codepython777 usb/i2c/... are all available to me
19:10 Hyratel https://www.pololu.com/category/10/brushed-dc-motor-controllers
19:12 Hyratel codepython777, have a look there ^
19:13 codepython777 Hyratel: Buy PI + https://www.pololu.com/category/97/pololu-qik-dual-serial-motor-controllers + Replace part 15 from here -> http://www.robotshop.com/en/4wd-hercules-mobile-robotic-platform.html#productsReviewBoxTitle
19:13 codepython777 Hyratel: why not just use part 15 from the 4wd hercules?
19:14 Hyratel IDK
19:14 Hyratel I'm just putting options out there
19:16 codepython777 Hyratel: Are there platforms that come with just good motors and i can add the polulu + pi on it?
19:17 Hyratel how big do you need it?
19:17 Hyratel the actobotics one I linked does
19:20 codepython777 Hyratel: I just need it to carry 3kg payload
19:21 Hyratel how big is the payload
19:21 Hyratel build soemthing out of actobotics
19:21 codepython777 actobotics - what are good motors to buy for it?
19:22 codepython777 oh it has motors
19:22 codepython777 4 motors
19:23 codepython777 Hyratel: If the number of motor channels available is 2, can it control 4 motors?
19:24 Hyratel yes
19:24 ace4016 technically, yes
19:24 Hyratel put the motors on one side wired together
19:26 codepython777 https://www.pololu.com/product/1567 - looks interesting
21:43 rue_house no steering, unless you put the tires in all different directions and have it hop into a new direction
21:44 rue_house all they had to do was put a hinge in the middle
21:45 rue_house the other one, notice in the video it just goes straight? thats cause thats all those can do
21:48 Hyratel rue_house, even with skidsteer commands?
21:52 rue_house correct
21:53 rue_house unless there is no weight on it. the only way those can turn is to hop the tires
21:53 rue_house tracks slip sideways, thats why they work
21:53 rue_house if you want to skidsteer something like that, you need to put a castor wheel on the back, not two driven wheels
21:54 rue_house so with those platforms, you weight them up and they refuse to turn
21:54 Jak_o_Shadows +1 for a castor wheel, it works
21:54 Jak_o_Shadows that's what my basic robot does
21:55 Hyratel https://dl.dropboxusercontent.com/u/33593534/images/Robot/DSCN2011-1k2.jpg
21:55 Hyratel this winds up sweeping the front wheels because there's a lot more weight in back
21:56 e_house and jester had a funny one, trying to make a 8khz voice recorder with an arduino and an SD card, turns out, the SD card can take up to 340ms to finish its w
21:56 rue_house which is waaaaay to long for the avr to buffer
21:57 rue_house Hyratel, yea, stronger than it is heavy
21:57 Hyratel at about 60 lbs with 1/2 HP per side... yeah
21:57 rue_house and turning on a flat surface being a high current activity
21:58 rue_house little difference on sticks or mud!
21:58 rue_house Hyratel, do you have a camera on it yet?
22:00 Hyratel no
22:01 Hyratel but I'm trying to get all the necessary Stuff to ddo so
22:01 rue_house ...such as a camera?
22:01 rue_house :)
22:01 rue_house what you woring on getting for it
22:01 Hyratel well I have a retired Axis camera I can use
22:01 rue_house remember that all digital systems will have about 3 seconds latency
22:02 Hyratel it's the first one that came in FRC KOP
22:02 Hyratel there's newer ones so I brought this one home
22:02 tws2172 old FRC :D
22:03 Hyratel dude i have an IFI board
22:03 Hyratel the school has ... 5 or 6 IFI boards
22:03 Hyratel they're plenty for most purposes
22:04 Hyratel but the limiting factor is powering the driver station
22:04 tws2172 yeah.
22:05 Hyratel <- FRC veteran-mentor
22:05 tws2172 <- college student. fresh out of FRC. lol
22:13 tws2172 Jak_o_Shadows: nice. I've built a small robot powerd by ROS. it uses a castor wheel on the back as well :P
22:13 tws2172 http://i.imgur.com/H0NBsy0.jpg
22:17 rue_house does its vision work ok?
22:18 tws2172 yeah
22:19 tws2172 the little thing on top is a LiDAR i ripped out of a NeatoXV vacuum cleaner
22:19 tws2172 which works really well surprisingly
22:20 tws2172 for SLAM and such
22:23 rue_house this arduino library for playing wave files is SO bad I'm starting to laugh
22:25 Jak_o_Shadows i installed ROSA THe other day
22:26 tws2172 Jak_o_Shadows: ROS?
22:26 Jak_o_Shadows RSO
22:26 Jak_o_Shadows yes
22:27 tws2172 nice
22:27 tws2172 it's really helpful
22:47 rue_house oh geez, he didn't even preload the buffers....
22:47 rue_house WTF
22:50 rue_house the sample rate is played at 62Khz, 31Khz, or 20.8khz depending on what the sample rate really is
22:51 rue_house nowonder the pitch sounds screwed
22:52 rue_house the volume is done by cutting off the offending peaks of the sample
23:17 codepython777 to build good pan tilt systems, do people use servos or steppers?
23:20 Hyratel codepython777, servos generally
23:20 Hyratel they don't require zeroing
23:23 codepython777 Hyratel: thanks
23:25 Hyratel I hope FRC gives the team another roboRIO next year so the team can *ahem* retire the cRIO
23:26 Hyratel I mean the roboRIO is cheaper than the IFI boards were and those were issued annually
23:30 codepython777 Hyratel: Do you know of a rail system which i could move a point in x-y with decent precision?
23:31 Hyratel try the Actobotics stuff sparkfun carries
23:40 codepython777 Hyratel: that looks pretty expensive. It would be nice to buy a toolbox like that for a few hundred dollars
23:41 Hyratel context?
23:41 codepython777 http://www.robotshop.com/en/robot-construction-kits.html
23:42 codepython777 something like a kit here?
23:42 codepython777 like vex for instance?
23:42 Hyratel use in a complete thought please
23:43 codepython777 Hyratel: does acobotics come as a kit one can buy , from which one can prototype different things?
23:43 codepython777 like the vex iq kit for instance?
23:43 Hyratel actobotics is a component line
23:43 Hyratel https://www.sparkfun.com/products/13141
23:45 codepython777 thanks
23:54 devshark few hundred dollars? you guys really don't like ordering from chinese websites, eh? :)