#robotics Logs

Mar 08 2015

00:23 codepython777 4 wheeled cars
00:55 mrdata codepython777, we can talk about it
00:55 mrdata what sort of measurements do you have?
00:56 mrdata eg: robot ascending ramp at particular angle
00:56 mrdata keep raising the ramp until it has trouble
00:57 mrdata or do you have power ratings for the motors etx
06:37 veverak http://www.redetec.com/product/
06:37 veverak why I want to believe that this would be as awesome as they say?
06:56 Anniepoo anybody having any luck with the Cornell jamming based universal gripper?
06:56 Anniepoo I just made one, and it's kind of iffy
06:57 Anniepoo the jamming works just fine, but it holds very loosely
07:03 Anniepoo I used diatomite based absorbant (industrial kitty litter), wondered if it was that, or the size (I put in as much as I could by hand in the largest party balloon I could find)
12:50 rue_bed er, coffee grounds from what I know
12:51 rue_bed or a non-euclidian material
12:51 rue_bed er
12:51 rue_bed pls stand by, brain is still booting
12:56 Tom_itx run linux and you never need to reboot
12:56 rue_bed not true, if you replace the harddrive you need to reboot
12:56 Tom_itx (or so they say)
12:56 rue_bed or if your machine dosn't have hot-swappable cards
12:56 rue_bed and or memory
12:57 Tom_itx hot swappable
14:44 Anniepoo non-Euclidean material?
14:45 Anniepoo I was certainly seeing the 'jamming' effect, it gets nice and hard, maybe my media is too large
14:46 Anniepoo I'l try coffee grounds
15:40 Anniepoo and, reading the Cornell PNAS paper, they used ground coffee (stuff you pour into filter basket) not coffee grounds (stuff you put in compost heap)
16:43 killerspec evening all
16:47 killerspec Anyone here know anything about adafruit motor shield v1? I am trying to figure out if I can pair the motors
19:30 rue_shop2 Anniepoo, dont drink coffee, wouldn't know
19:33 Tom_itx rue_shop2 what you workin on nowdaze?
19:44 rue_shop2 I spent the day gathering togethor a lawn mower, but after I got it going and used it for a bit, it developed a knock, I think the connector rods comming off the crank
19:44 rue_shop2 I'm printing another printer
19:44 rue_shop2 I should take pics
19:44 rue_shop2 slightly bigger, just for convenience of material size
19:44 rue_shop2 bbl shopping
20:03 Anniepoo rue_shop2, I don't either, but will try to get some
21:18 Loshki Tom_itx: "run linux and you never need to reboot" <--- To be fair though, all that time you save not doing reboots you spend doing configuration.
23:28 rue_house Triffid_Hunter, oh, 30898 is yours...
23:29 rue_house Triffid_Hunter, http://www.thingiverse.com/thing:715465
23:31 Triffid_Hunter rue_house: hm
23:31 Triffid_Hunter ?
23:31 rue_house nowonder the origional design was so nice
23:31 Triffid_Hunter rue_house: if you want an overengineered Y motor bracket, check out 15988 :P
23:32 rue_house anyhow I took a shortcut and did the profile using a dxf outline, you had about 10M objects to make the origional is csg
23:32 codepython777 does anyone have a pointer for an outdoor lidar sensor that is good?
23:32 rue_house Triffid_Hunter, I'm gonna guess you had a reason for making it so thick
23:32 Triffid_Hunter codepython777: I've used hokuyo urg LX04, those are pretty nice.. nothing is gonna work well in full sunshine though
23:33 Triffid_Hunter rue_house: belt damage from the motor axle not being perpendicular to the belt, due to bracket flex under belt tension
23:33 rue_house why were you trying to make a heavier bracket?
23:33 rue_house ah
23:33 Triffid_Hunter rue_house: with that crazy beefy thing, almost all the forces on the bracket are in compression rather than torque
23:33 rue_house ok
23:33 Triffid_Hunter codepython777: also, those hokuyo sensors cost $2k last time I checked ;)
23:34 rue_house Triffid_Hunter, I upsized my new machines by 5cm, makes the rod eaiser to cut
23:34 codepython777 Triffid_Hunter: how far can they see?
23:34 rue_house machine
23:34 Triffid_Hunter rue_house: also, I wanted to make somthing that actually needed a 50mm bridge
23:34 codepython777 its a planar sensor, right? not real 3d?
23:34 rue_house eek, only 1 so far
23:34 Triffid_Hunter codepython777: umm 4m from memory, with 1mm precision
23:34 rue_house heh
23:35 Triffid_Hunter codepython777: yeah the sensing zone is a flat circle
23:35 rue_house I'm starting to think that the X ends were really just a bridge test
23:35 rue_house the problem my working machine is having is that those bearing walls are eating my belt
23:37 Triffid_Hunter the MMax just uses two bearings side by side with no flange, seems to work pretty well
23:37 Triffid_Hunter and the belt runs on smooth metal
23:39 rue_house I put a U shaped spring on mine to bias the belt to the middle of one bearing, its happy
23:39 rue_house I'll take a pic of that one
23:51 rue_house Triffid_Hunter, http://ruemohr.org/~ircjunk/projects/reprap/p1070120.jpg
23:51 rue_house http://ruemohr.org/~ircjunk/projects/reprap/p1070116.jpg
23:51 rue_house http://ruemohr.org/~ircjunk/projects/reprap/p1070117.jpg
23:51 rue_house http://ruemohr.org/~ircjunk/projects/reprap/p1070118.jpg
23:51 rue_house http://ruemohr.org/~ircjunk/projects/reprap/p1070119.jpg
23:52 rue_house ads a *tiny* bit of friction, keeps the belt perfectly on the bearing