#robotics Logs

Jun 01 2014

01:07 rue_more its formulas like that I'm glad I wrote my command line parser for
01:07 rue_more I can switch the variables up and not have to re-enter the formula
01:30 MrCurious slow night
01:33 rue_more wow, the req'd inductor size flips out at hv out, low current
01:33 rue_more 2mH
11:54 rue_more V = Li/t
11:54 rue_more so L=
11:54 rue_more Vt/i
11:55 rue_more with an applied voltage, the cujrrent will ramp up
11:56 rue_more if I stop the ramp at a particular current, the only factor left is time
11:56 rue_more there fore L=k*t
11:56 rue_more where k is a magic number
12:37 rue_more say, 5V/.02A
12:38 rue_more L = 250*t
12:38 rue_more so 2mH
12:39 rue_more 8 us
12:42 rue_more with an avr at 20Mhz, that would be 160 timer ticks
13:42 MrCurious http://dailydigestnews.com/2014/06/amazing-raptor-robot-can-run-faster-than-usain-bolt-video/
13:42 MrCurious now that is a running robot
13:44 robotustra this news is out of date
13:45 MrCurious i am expired
13:45 robotustra and if it can run faster than cheetah it does not mean that it will actually do
13:46 robotustra and to use hyroscope for stability is a cheating
13:47 robotustra hyroscope is bigger than the robot itself
13:47 robotustra and not secure at all
13:48 botustra OMG, I'm speaking like cana
13:49 MrCurious you have become quite the curmudgeon
14:10 kidd hay every one
14:10 kidd some one to talk about mobile shelving
14:11 MrCurious for warehoues, where the shelves move past the pickers rather than pickers moving past th shelves
14:11 MrCurious its been done
14:13 robotustra I would think that place with moving shelves is quite suspisious
14:14 MrCurious have seen it its little 8" tall robots that raise and lower shelves
14:14 MrCurious http://www.technovelgy.com/ct/Science-Fiction-News.asp?NewsNum=1300
14:14 robotustra ah, amazon robot
14:15 MrCurious yeah
14:15 MrCurious its a clever idea
14:15 MrCurious in soviet amazon, shelf comes to you!
14:24 MrCurious kidd: talk here...
14:25 kidd https://www.youtube.com/watch?v=Og5gpAa9LqQ
14:26 MrCurious nifty design, but a bigger room would likely have been cheaper
17:13 GuShH Tom_itx: indicated the test taper on a jacobs 6mm chuck, brand new... the runout (based on the indicator I have) is 0.014mm so about half a thou, not bad... of course once I remove it from the chuck, it won't be actually concentric anymore but as a test for cutting the taper, not bad. I can't see any movement when the indicator is touching the taper, which is obvious... since we're centered to the 3 jaw chuck.
17:13 GuShH should most likely turn this between centers if I attempt to make a complete arbor
17:14 GuShH I was indicating the outside (near the front) of the jacobs chuck, not something chucked in it. I think half a thou to a thou is pretty good for a jacobs chuck
17:14 GuShH we'll see how well it chucks though, I expect 0.05 runout at least near the jaws
17:19 GuShH 0.03mm runout using a 3mm straight rod without tightening it too hard, because the test arbor is aluminum so it would easily bend.
17:19 GuShH that's surprisingly good for a jacobs type chuck
17:19 GuShH 1.2 thou worst
17:21 GuShH not the most accurate indicator, but it's good enough for now. as long as it's parallel to the work, it shouldn't be that far off, but I would use a smaller range indicator if I had it (0.001 instead of 0.01)
17:21 GuShH what's the expected runout on a regular set of collets?
17:22 Tom_itx 0.0000
17:22 GuShH haha no, really
17:22 Tom_itx is what i expect
17:22 GuShH .0002" says on a forum
17:22 GuShH ER32 spec
17:22 GuShH but, that's not what you get from a chinese set is it.
17:23 GuShH (I know it's an unfair comparison, I'm actually just trying to inform myself)
17:23 GuShH they're different things for different purposes.
17:23 GuShH .0006" on an import set, says another guy.
17:24 GuShH now include the runout of the taper in your spindle
17:25 GuShH and it's already worse than the test setup I have right now (which I know is not realistic, once I remove it from the chuck it's going to have massive runout)
17:26 GuShH I think my spindle is 0.01mm out, at least, but that's just near the taper face, who knows with a taper in there... I should try it with a dead center, but I'll get depressed.
17:30 GuShH http://mla-s2-p.mlstatic.com/palpador-aleman-con-base-en-caja-de-madera-para-torneria-11196-MLA20040112864_012014-F.jpg
17:30 GuShH is that an adapter for a dial indicator?
17:31 GuShH "otto littmann precision"
17:31 GuShH looks like the spindle mount type, but for a regular dial indicator instead of a test indicator
17:45 SquirrelCZECH hi folks
17:45 uirrelCZECH found this awesome http://www.kosagi.com/w/index.php?title=Novena_Main_Page
17:45 SquirrelCZECH basically nice motherboard for hacker's laptop
17:46 SquirrelCZECH any idea of similar projects, but ... with better than first version? :)
17:46 uirrelCZECH likes it, but doesn't like first version of projects in gen
19:56 GuShH meh, servicing the compound. I'm sick of that slightly bent leadscrew (gives a tight spot across half a revolution) I should really convert it to thrust bearing with a new screw, but how would I cut the half-moon keyway on the new part?
20:05 robotustra hm
20:49 Tom_itx GuShH with a dremel
23:20 GuShH Tom_itx: maaaybe...
23:52 rue_shop2 the bearings in the dolly... arent....even....hardened!?!!!
23:53 rue_shop2 one of the disintegrated
23:54 rue_shop2 16mm-35mm x 11-ish mm
23:54 rue_shop2 can anyone name the beraing?
23:55 rue_shop2 6202
23:55 rue_shop2 ya know that sounds familiar
23:59 rue_shop2 haha! shop in stock!