#robotics Logs

Jul 07 2013

00:00 Jak_o_Shadows oops
00:13 MrCurious YAY! no magic smoke!
00:17 GuShH hu?
00:20 MrCurious did you hear Oxygen was dating Magnesium... O Mg!
00:23 rue_shop2 19cm, 0.7kg
00:24 rue_shop2 hmm over 20A
00:24 rue_shop2 I cant measure over 20 right now
00:25 rue_shop2 how many kg-cm is that?
00:25 rue_shop2 27kg-cm?
00:25 Jak_o_Shadows I was leaning towards 13.3...
00:25 Jak_o_Shadows I dunno, I normally convert to Nm, then go from there
00:26 rue_shop2 ah, I think your right
00:26 rue_shop2 ok hmm
00:27 rue_shop2 its the stall torque of the vacuum motor I have at 60V and about 5 feet of #16 wire
00:27 rue_shop2 I was close to measuring the rpm at 60V, but one of my rare earths flew off the shaft
00:28 rue_shop2 I think it was over 20000
00:28 rue_shop2 if they put out 30k
00:28 rue_shop2 6:1 to the transmission
00:29 rue_shop2 so you get more than 80kg-cm from each motor
00:29 rue_shop2 35 motors...
00:29 rue_shop2 2793kg-cm
00:30 Jak_o_Shadows Is this clustering them? What about the heat buldup?
00:30 rue_shop2 202 foot-lbs
00:31 rue_shop2 the engine specs are...
00:31 rue_house hahaha 123 to 135 foot-lbs
00:32 rue_house I think vacuum motors will work...
00:32 rue_house there would be airflow to deal with heat
00:33 rue_house I'm gonna die laughing if this works
00:38 rue_house according to the same calcs, 2 vacuum motors will run my lawn tractor
00:38 rue_house 2 or 3
00:38 rue_house I have to check the rpm on that motor before I can try that tho
01:14 rue_shop2 I have to get the truck up on some blocks and work out the diff ratio
01:20 MrCurious DAMNIT circuit bug!
01:20 MrCurious oh IC, its missing 4 wires
01:21 MrCurious but that still leaves the mystery of the overheating voltage regulator
01:41 MrCurious 1 of 2 steppers stepping. wiring flaw found :D
01:42 rue_house linear regulator?
01:42 MrCurious i had regulators compeeting
01:43 MrCurious clipped the joining of 3 different +5 out's
01:43 MrCurious and they cooled
01:43 MrCurious now the stepper chip A3967 is heating
01:43 MrCurious but i THINK it has a thermal shutoff, so will just have to watch it
01:43 MrCurious boards are cheap enough
01:43 rue_house so if you replace them with one smps regularot it'll give you that current your drawing with 3x the efficiency
01:44 rue_house did you know the car usb adapters you can get on ebay for $1 have a smps in them?
01:44 MrCurious i think it will be fine
01:44 MrCurious the 5v is just feeding the A3967 now
01:44 rue_house alot of peope think that about a lot of things
01:44 MrCurious so not much pill at all
01:45 MrCurious given its a COTS stepper board
01:45 MrCurious and i am space constrained, i will just have faith for now
01:46 rue_house the smps boards are about 1cm x 3cm
01:47 MrCurious sounds like the 5v dc-dc converters the robot is laced with
01:48 MrCurious for anywhere i need a non trival 5v
02:14 rue_house do you think I can run 4kw thru a 10mm timing belt? (30k rpm)
02:14 rue_house I wonder if it would just melt from internal heat
02:17 rue_house 7*12V = 85V aka averare of 120Vrms
02:18 rue_house (ish)
02:19 Jak_o_Shadows1 Um, surely you can just do the calculations?
02:19 MrCurious 30W of steppers
02:20 MrCurious 20W for 4 steppers at 15v
02:24 rue_house fets for this are basically dirt cheap
02:24 MrCurious 2 motors working acceptably
02:25 MrCurious running in half step mode
02:27 MrCurious now for sleep :)
02:50 rue_house http://www.bb-battery.com/productpages/HR/HR9-12.pdf
02:50 rue_house according to this, if I use these to convert my litte tractor as a tet
02:50 rue_house tet
02:50 rue_house test
02:51 rue_house if I pull 30A I'll get less than 10 mins
02:51 rue_house 20 mins if I use 14 of them in a 7s2p setup
03:14 Jak_o_Shadows1 http://jak-o-shadows.users.sourceforge.net/electronics/random/robotArm1.PNG Arm idea so far.
03:16 rue_shop2 theBear, damn, your right, the fet driver chips are specific for synchronous converters, there is no high imp. mode
03:22 Jak_o_Shadows1 Bottom part is some plumbing bits, which I think will work ok when greased. Not as well as a proper thurst bearing. Probably mount the servo underneath, not rotating, so that less wires have to rotate.
03:22 Jak_o_Shadows1 The gripper will probably just be a servo-actuated clamp thing, for the time being.
03:29 rue_house "the numbers dont lie, they just hide inconvienient thruths"
03:29 rue_house "STOP! STOP! Your dieing in my FOOD!"
03:37 rue_house "my password is FBIiswatchingyou, the idea is that no hacker dare type it in"
03:40 rue_house "how did this happen?" "Bert and Sammy were duck hunting, Bert fired and Sammy didn't duck"
03:46 rue_house "whats the fastest way off this bridge!?" "uh.." "AAAAAAAAAHHHHHHHHHHHHHHhhhhhhhhhhhhhhhhhhh.... thud"
03:55 rue_house I'm getting sceptical that an engine can really do 5000 rpm
04:30 rue_shop2 this 1" grade 8 bolt looks about the same size as the transmission input shaft
04:30 rue_shop2 but I'll need a longer one
04:30 rue_shop2 about 48"
05:04 rue_shop2 hehe, i just made a 7" 7 segment
12:00 robotustra hi
12:06 rue_house hi
12:08 robotustra ca va?
12:52 rue_house ni
13:24 GuShH rue_house: hi
13:24 GuShH sup
13:26 robotustra BA!
14:02 GuShH robotustra: RU!
14:26 GuShH robotustra: finished cutting for one of the 3 projects
14:26 GuShH the other one is half way there, it's a bit complicated though... so I might have to rethink a few things, now I'll start cutting the parts for the stand.
14:26 GuShH (all one or two centimeters longer, because as much experience as you can have with an angle grinder, you can't get perfect cuts)
14:27 GuShH (can't justify more tools for this though)
15:07 MrCurious ugh 20 watt draw for 4 steppers
16:37 MrCurious apparently the first 3 days of the 4 day weekend have depleted me.
16:41 ace4016 same
16:43 MrCurious got 2 of my 4 steppers wired for my quad omni wheel base
16:43 MrCurious nice watching them do 1 rev, then pause
16:45 MrCurious with luck, i will locate my motivation before bedtime, and get it completed
16:46 MrCurious ace4016: what are you procrastinating on
16:58 ace4016 MrCurious, lots of things
17:01 MrCurious heh
17:02 GuShH MrCurious: you suck, go complete it nao.
17:02 MrCurious i do
17:02 MrCurious but i have only been awake an hour
17:03 ShH slaps MrCur
17:12 GuShH Bleh... Dewalt discs are not as good as they used to be... I'm all for Bosch now!
17:26 MrCurious bosh are expensive no?
18:13 MrCurious time is the precious ambrosia of which we all sip...
18:14 MrCurious and we dread the day that we have had our fill.
19:09 GuShH rue_house: what height did you end up with for your lathe stand?, I'm aiming for 83CM, which is the same as the height of my wood lathe stand, which I find to be almost perfect, height wise.
19:10 GuShH crap, need to remove some rusty steel screws from a wood frame...
19:10 GuShH when will people learn to use stainless or brass instead
19:10 Tom_itx i'd go for a working height around the same as a kitchen countertop
19:11 Tom_itx so when you're standing there the chuck is just above waist high
20:02 xxoxx all your base are belong to us
20:03 zhanx that was so 20 years ago, now its all your outsource belong to us
20:05 xxoxx all your base were belong to us
20:05 zhanx akk your base we sold to them
20:05 zhanx all
20:06 xxoxx all your base shall belong to us
20:06 zhanx akk your base shall be sold to us
20:07 xxoxx all your base might belong to us
20:07 zhanx all your base robots took
21:13 xxoxx all your base are belong to us
21:32 MrCurious all hail the rise of homo-roboticus!
22:27 GuShH MrCurious: https://www.youtube.com/watch?v=dpqBhYW74Ho
22:36 MrCurious testing....
22:39 billmania MrCurious: 1, 2, 3
22:39 GuShH sleep gym would totally work for you
22:40 MrCurious wheels 3 and 4 are not spinning. got a big
22:40 GuShH got a big...?
23:09 MrCurious 3 motors turning, 1 just hard clamps
23:27 GuShH MrCurious: irrelevant to human kind
23:47 MrCurious and fried avr