#robotics Logs
May 27 2012
#robotics Calendar
00:01 m_itx goes to sleep o
00:09 katsmeow-afk congrats Tom, thanks for the stepper/electronics performance report
00:36 rue_shop well the output from the encoder isn't pretty, but all 4 states are there
00:39 rue_shop hahah I just worked out that I can determine the shutter speed of the digital camera with the oscilloscope
00:39 rue_shop count the retraces or other
00:41 katsmeow-afk show a megahertz sinewave, and count each waveform as a microsec ?
00:41 rue_shop lots of ways, but an entertaining realization
00:42 rue_shop ok well, I have a distance encoder for the mowerbot
00:42 tsmeow-afk tosses a peppermint candy to Tom and
00:42 rue_shop now I need to work out a) whats gonna count the pulses b) how the data will get relayed off the castor (NO RF)
00:43 e_shop gives kat a peppermint paddy for her good work on her water sy
00:43 katsmeow-afk a magnetic tooth wheel passing by a hall effect sensor , use two sensors for quadrature direction decoding
00:43 rue_shop no I already made a sensor
00:43 katsmeow-afk ok
00:44 rue_shop I need a microcontroller to count it and transmitt it somehow off the castor
00:44 katsmeow-afk i suggest a dedicated counter so a cpu getting interrupts by something else won't miss counts
00:44 rue_shop yea, I was thinking an 8 pin avr
00:44 rue_shop have it transmitt as serial data
00:44 rue_shop just an 8 bit count that rolls over
00:44 rue_shop the computer can work out the rolling
00:44 katsmeow-afk pop the tire off the rim and fill it with batetries
00:45 rue_shop power isn't a problem I can brush and filter it
00:45 rue_shop getting the data back off is my problem
00:45 rue_shop I'm thinking either magnetic coupling like in a vcr
00:45 rue_shop or optic
00:45 katsmeow-afk brush and filter it?
00:45 rue_shop but it uses a 1/2" bolt for the pin, its not hollow
00:46 rue_shop power via commutator
00:46 rue_shop frame ground, insulted ring for +
00:46 katsmeow-afk then get the signal off by current modulating the power
00:46 rue_shop the power will be noisy from the grinding brushes
00:46 katsmeow-afk filter it
00:46 rue_shop yea, but the data is like 10Khz
00:47 katsmeow-afk time-mux it, 10ms charged the psu caps for the avr, the next 10ms the avr sends data out, repeat
00:47 rue_shop which is well into the noise reagon, so data over power wont work
00:47 rue_shop I think optic or magnetic is the best....
00:48 rue_shop I'v lit up leds via a vrc head with 1Mhz modulation
00:48 katsmeow-afk so did i, but you talked me out of that because there wasn't any power on the castor
00:48 rue_shop its got all the power it can eat with the brushes
00:49 katsmeow-afk but you see, i gave up months ago, because back then there was no power
00:49 rue_shop I'm sorry I dont recall
00:50 rue_shop too bad that damned pin isn't hollow
00:50 rue_shop that would fix it all
00:50 katsmeow-afk must it be hollow? why not groove it?
00:51 rue_shop !
00:51 katsmeow-afk or use some 3/8 water pipe?
00:51 rue_shop your right, a groove about 3mm deep, less, would be enough to get a wire up to the top
00:51 katsmeow-afk yeas, i know
00:51 rue_shop the led could go between ground (the bolt itself) and the wire
00:52 rue_shop :-) SWEET! thanks kat!
00:52 katsmeow-afk you may not need to groove the entire bolt
00:52 rue_shop it dosn't even weaken the bolt enough to matter
00:52 katsmeow-afk right
00:52 katsmeow-afk and a lil epoxy, you'd never know
00:52 rue_shop well, ok, its a plan then
00:53 katsmeow-afk all it takes is about 2 minutes with a thin zip disk in a body grinder
00:53 e_shop
00:54 rue_shop I wonder, one of the bearings is just a bushing...
00:54 rue_shop have to be carefull there's no burr
00:54 rue_shop OR glue a little pipe in the groove
00:54 rue_shop then I can change wire at will
00:54 rue_shop ok its a start
00:55 rue_shop I now need to make a working IR link for serial data, that should be trivial
00:55 katsmeow-afk or put the ir diode elsewhere, and route the fiber optic up or down the groove
00:56 rue_shop if the pin were hollow I'd use it as the optic path
00:56 rue_shop but I can make a groove work, I just need to make a thingle at the top to hold the led
00:57 rue_shop I'll have to put a box around it, but I have to anyhow to make the encoder that determines the castor direction
00:58 katsmeow-afk a thingie or a thimble?
00:58 rue_shop thingle
00:58 rue_shop its a thing thats like a dongle but its not
00:58 katsmeow-afk thimble might work better, it's the right size, metal, hard to damage, cheap, etc
00:59 katsmeow-afk and hollow so you can put things into it
00:59 rue_shop we shall see, I need supper
00:59 rue_shop the robots are in
00:59 rue_shop the welder is in
00:59 katsmeow-afk http://en.wikipedia.org/wiki/Thimble
01:14 katsmeow-afk ok, the last non-pvc-to-pvc connection , which began leaking last nite, is now epoxied like the others that do not leak any more
01:14 katsmeow-afk i still worry about it, i have never had any luck with female threaded pvc
01:14 katsmeow-afk the pvc cold flows under pressure, it just lifts off whatever is screwed into it
01:15 katsmeow-afk i pulled some 3/4 pvc pipe that had county water on it for ~6 yrs, it didn't fit into new pvc connectors anymore, it was all oversized
01:36 tsmeow-afk ponders.. pulverising peppermint candy, push it thru an ro filter to remove the pink, then evaporating it to ........... no, the ro would remove the sugars
02:15 katsmeow-afk The findings of Dunning and Kruger are being reduced to "Stupid people are so stupid that they don't know they are stupid."
02:17 katsmeow-afk In other words, narcissists think they are brilliant. Who knew? In addition, the researchers found that extroverts were also more likely to overestimate their abilities, while self-esteem and gender were not correlated. And, importantly, none of these seemed to be correlated to actual performance.
02:29 tsmeow-afk looks at the 64Gbytes of chip data in one fo
02:48 rue_mohr aha
02:48 e_mohr works out why he's so t
02:49 rue_mohr threaded pvc is a bad thing
02:49 rue_mohr to all my experiance
02:49 rue_mohr worst when threaded against metal
03:51 katsmeow-afk yeas, and what sprung a leak last nite was threaded pvc over brass, it's epoxied in now, i put epoxy in the pvc threads too before i reassembled, so there's a bead of epoxy around inside
03:52 katsmeow-afk if it leaks again, then the epoxy obviously didn't hold, i'll unscrew it and make up some pvc male to some other way to get 1/4 npt, and solvent weld the mess together into the valve
06:23 Qasaur hey guys
06:29 KongfuPanda hi Qasaur
07:28 katsmeow-afk It started when a Muscle Shoals business alerted authorities that someone had placed materials from a meth lab in its garbage bin. When it happened a second time, Colbert County deputies dug through the trash. Along with the mess form the meth, they also found someone's mail. It included phone and cable bills.
07:28 katsmeow-afk Investigators used the information to arrest Larry Mason of Tuscumbia. He's now charged with manufacturing and possession of drugs.
09:17 rom so.... monitoring energy consumption? where do i start?
09:21 Triffid_Hunter rom: power = voltage * current, energy = power * time
09:21 Triffid_Hunter rom: so need to monitor voltage and current and keep a running sum of the product
09:22 rom i gathered that, but practically, how do i go about measuring the voltage and current used by say... a motor? without strapping a multimeter to the robot
11:08 rue_bed awe he left
11:08 Tom_L you sleep too much
11:17 rue_bed yea, something is wrong, not sure what yet
11:18 rue_bed I think its a bit too much stress
11:18 rue_bed but its only 9am
11:19 rue_bed I'm typically not up for another hour yet
11:20 m_itx watches the sun rise a
11:29 e_bed peers out between the curtins at the semi-sunny wea
11:30 rue_bed hmm what to do today
11:31 rue_bed wonder if I can find that servo manager process I wrote
11:31 rue_bed ah, I should make a cope and drag for casting that roller
11:31 Tom_itx a who?
11:32 rue_bed I dont have a thing large enough to cast the roller
11:32 Tom_itx how big is it?
11:32 rue_bed about 6"x6"x12"
11:33 rue_bed and I have to cast it vertically from what I can tell
11:33 Tom_itx why?
11:33 rue_bed shrinkage
11:33 rue_bed they say over 12" you get 1/4" shrinkage vertically
11:33 rue_bed but not much horiz
11:34 m_itx looks at rue_bed's garden beds and suggests a box like
11:34 rue_bed heh
11:34 rue_bed I should have somehting I can pour out
11:34 rue_bed but hte sand is the trickey part
11:34 rue_bed need to make casting sand
11:34 rue_bed its that bentonite clay thats the hangup
11:36 rue_mohr I can dig up really fine clay here but its a lot of work
11:36 Tom_itx these stepper drivers, like your welder are things you look back on and are glad you paid for instead of made
11:36 Tom_itx so far i'm very pleased
11:37 Tom_itx now if i ever get to build a heavier mill i will have the stuff to drive it
11:38 Tom_itx i think next in order is an enclosure for the psu, drivers and control electronics
11:45 Tom_L http://www.ebay.com/itm/ENCLOSURE-ELECTRICAL-CONTROL-CABINET-20-X-20-X-8-/390412531626?pt=BI_Electrical_Equipment_Tools&hash=item5ae66677aa
11:45 Tom_L similar to what i'm after
12:34 Steffanx Ha KongfuPanda
12:34 riarty feeds KongfuPanda with bamboo sh
12:35 KongfuPanda Steffenx, hello
12:35 Steffanx Steffen … :(
12:35 KongfuPanda moriarty, hi
12:35 KongfuPanda Steffanx*
12:35 KongfuPanda Степан
12:35 KongfuPanda дядя Стёпа - великан, провалился у стакан
12:36 Steffanx Russian..
12:36 moriarty he just called your mum a whore
12:36 Steffanx Which language is that KongfuPanda ?
12:36 KongfuPanda omg, you lying bastard
12:36 KongfuPanda Steffanx, yeah, Russian
12:37 KongfuPanda Steffanx, we have a cartoon about "uncle Stepa", short for Stepan = Steffan
12:37 Steffanx I wonder how correct google translate is
12:37 Steffanx "Uncle Stepan - a giant, fell from a glass"
12:38 KongfuPanda and children made a saying that rimes but doesn't make sense really :D "Djadja Steva - velikan, provalilsja u stakan"
12:38 moriarty это пиздец
12:38 Steffanx You speak russian KongfuPanda ?
12:38 KongfuPanda http://www.youtube.com/watch?v=57cEWA4W_KY
12:38 KongfuPanda yeah
12:38 KongfuPanda of course
12:39 KongfuPanda you didn't know?
12:39 Steffanx No, you're not from that country iirc
12:39 KongfuPanda moriarty, how do you know russian?
12:39 moriarty Какого хрена ты его слушаешь? Ни хрена он не знает!
12:39 Steffanx Great cartoon KongfuPanda
12:39 KongfuPanda I'm origianally from Ukraine
12:40 Steffanx Yeah, but that language is a little different from Russian isn't it?
12:41 KongfuPanda Steffanx, yeah, it is. But my father is Russian, and we lived near the border with Russia. Everyone speaks mixed language there, not Ukrainian and not RUssian :D I live in the UK now
12:41 moriarty KongfuPanda, from the toilet walls in Moscow
12:41 Steffanx lol moriarty
12:41 KongfuPanda moriarty, how often do you go to RUssian?
12:41 KongfuPanda a*
12:41 Steffanx -n
12:42 Steffanx Soviet Russia :D
12:42 Tom_itx what period would a 350khz signal be?
12:43 Steffanx 2.8us ?
12:43 Steffanx 9 even
12:43 KongfuPanda 2.86 us
12:43 moriarty ^
12:43 KongfuPanda 2.8571428571428571428571428571429e-6
12:44 Steffanx I go for 2.9 P:
12:44 moriarty KongfuPanda, not often but i quite like Saint Petersburg
12:44 Steffanx Tom_itx zlog can't do that anymore/
12:44 Steffanx ?
12:44 moriarty how about you?
12:44 Tom_itx no that was a different bot
12:44 Tom_itx i didn't like some features about it so reverted back
12:45 KongfuPanda moriarty, I've never been to St Petersburg. I only been to the border villagers between Russian and Ukraine (where my father is from), and to Siberia (where my crazy mother got married to some guy maybe 10 years ago) we went to see my grandmother (she divorced that guy a two years after)
12:45 KongfuPanda moriarty, Novyj Urengoj
12:47 KongfuPanda https://maps.google.co.uk/maps?q=Novyj+Urengoj&hl=en&ll=60.152442,90.703125&spn=81.296458,270.527344&oe=utf-8&client=firefox-a&hnear=Novy+Urengoy,+Yamalo-Nenets+Autonomous+Okrug,+Russia&t=h&z=3
12:48 KongfuPanda moriarty, we had to take two planes and a helicopter to get where she lived
12:48 moriarty ah yes, the Urengoj gas city :)
12:48 moriarty that's pretty cool, how is it up there in the North?
12:48 Steffanx Russia = gas country :)
12:50 KongfuPanda it was nice as I remember. I was like 7 or 8 when we went there though
12:51 KongfuPanda we went in august, so it wasn't as cold as it is in winter, but there were a lot of blood drinking bugs. Also, my birthday is in AUgust and I got a big smoked sturgeon as a present from one of indigenous people who lived there
12:52 KongfuPanda and there were many big fluffy dogs and huge ships
12:52 KongfuPanda small trees, mushrooms, and a very nice berry called "moroshka"
12:53 KongfuPanda http://en.wikipedia.org/wiki/Rubus_chamaemorus
12:53 KongfuPanda English common names include cloudberry, bakeapple (in Atlantic Canada), Knotberry and Knoutberry (in England), Averin and Evron (in Scotland).
12:54 KongfuPanda and also there were many helicopters there, and since my grandmother's husband was working on a petrol station for helicopters, I had a chance to go into an army helicopter and push buttons in the cabin
12:54 KongfuPanda was nice for a 7 year old :D
12:58 ngfuPanda pokes mori
12:58 riarty has a hole
12:58 riarty glares at KongfuP
12:58 KongfuPanda anyway, back to crystallography
13:01 Steffanx Is that as difficult as it sounds?
13:57 rue_mohr b: you can tell where I got shot last week eh? (elbow is blue)
13:57 rue_mohr r: yea, washes right off eh?
13:58 rue_mohr b: well I haven't had a shower in like 2 weeks
13:58 rue_mohr r: yea I can tell
13:58 rue_mohr k: I'll hose him off before we get back
13:58 rue_mohr r: thanks k!
14:00 Steffanx ok :S
14:02 rue_mohr the guys and their paintball
14:12 rue_mohr geez, I havn't checked my bank account in a while.... I'm doing a good job at not spending money
14:14 rue_mohr how long is 1267 months?
14:15 Steffanx I think i check it daily .. 100 and something years
14:15 Steffanx +\n
14:15 rue_mohr huh, I'm not gonna live to see my mortguage paid off
14:15 Steffanx I check mine daily, even when i'm pretty sure nothing changed
14:15 Steffanx Like in the weekends
14:17 rue_mohr huh, theres enough in the account to carry the mortguage for over a year
14:19 Steffanx :D
14:24 Tom_itx rue_mohr, to check phase of on 2 transformer's secondaries can i connect one leg of each secondary together and measure the voltage on the other two? if they are double what they should be it's backward, if it's zero they are in phase... ?
14:25 Tom_itx i know the primaries are in phase
14:26 Tom_itx thinking about rewiring this and eliminating a couple bridges
14:28 rue_mohr tom yes
14:28 rue_mohr BUT
14:29 rue_mohr the transformers may be a bit different, and f you wire them in parallel they MIGHT fight a bit
14:29 Tom_itx they are as similar as they can be
14:29 rue_mohr check the voltage difference when their in parellel
14:29 rue_mohr when they are in phase, if its more than 2V difference, I suggest not doing it
14:29 Tom_itx they won't fight anymore this way than they are connecting after the bridges will they?
14:30 Tom_itx it's not more than 2v
14:30 rue_mohr no, the bridges isolate them
14:30 Tom_itx it would be more like .xx v
14:30 Tom_itx i will check though
14:30 Tom_itx so if i have more v than say 2 across the secondaries, it's not a good idea...
14:31 Tom_itx i can leave it like it is
14:31 Tom_itx that's not a problem
14:31 Tom_itx i just thought it was wasted parts
14:31 Tom_itx it worked flawless all night last night
14:50 rue_mohr ok I got the rack on the truck, have to go buy stuff
14:51 Tom_itx bring me some
14:51 Tom_itx i need an 18 x 18 x 8 enclosure delivered
15:25 katsmeow-afk According to the settlement, approved by U.S. District Judge Tom Lee, district employees will stop handcuffing students younger than 13, and can only handcuff older students for crimes, and no student may be handcuffed to railings, poles, desks, chairs or other objects.
15:27 katsmeow-afk it bothers me that they "can only handcuff older students for crimes", that says they cannot expell them, counsel them, or give them some form of work duty
15:53 Tom_itx maybe they resorted to tazing the young ones
15:54 katsmeow-afk prolly, southern schools suck in every way
15:54 Tom_itx well ours do too
16:08 katsmeow-afk Tom, do you understand how the diodes isolate the transformers from each other?
16:11 katsmeow-afk the complicated version *why* you want them isolated : http://www.scribd.com/doc/40609400/Power-Transformers-in-Parallel-w
16:13 katsmeow-afk the easy version of *why* : http://sound.westhost.com/xfmr2.htm#s82
16:15 katsmeow-afk what the diodes do is make sure when the sinewave is positive, it is also only positive at the same time on the diode block outputs, and furthermore, no reverse power can possibly flow from one transformer to the other unless a diode is shorted
16:17 katsmeow-afk there is slao the issue of power dissipation, running two transformers thru one loaded MDA250x may drop 2v at 15amps, that's 30 watts, if your heatsink struggles to dissipate that the block will overheat, but two blocks on the same style sink will dissipate only 15 watts each
16:19 katsmeow-afk putting bipolars or diodes in parallel is the same issue as paralleling transformers, without the thermal runaway issue, but you can't solve transformer circulating currents with resistors
16:20 katsmeow-afk for your situation, being able to use a diode block on each transformer was a win-win
16:21 rue_mohr ok I got 24' of 2" abs, 8 90's and 2 T's for trying a mockup of the mecha frame
16:21 rue_mohr see what I see
16:21 rue_mohr got wood for expanding the potato boxes
16:21 rue_mohr got ICE CREAM for dealing with the heat
16:21 katsmeow-afk also, diffeent *styles* of transformers with the same voltages are really bad news when paralleled
16:22 rue_mohr yea, mathcing the internal resistance is important, same as when paralleling transistors
16:22 tsmeow-afk never heard of using ice cream to deal with hot pota
16:22 rue_mohr the hardware store had no 6" steel 'track' for making a cope / drag
16:23 katsmeow-afk why did you get bendy abs instead of pvc?
16:39 Tom_itx i was just asking
16:40 Tom_itx i may move the diodes to the heatsink once i get an enclosure anyway
16:42 tsmeow-afk
16:44 katsmeow-afk the diode blocks in my psu are so close together because they are on heavy aluminum with a fan airflow at all times, and altho pulling 8amps won't hurt the electronics, i don't expect to be doing that, or for very long
16:44 tsmeow-afk will do tests before putting the ratings in wri
16:45 katsmeow-afk fwiw, if i were going to parallel 2 windings on the same transformer, wound with the same wire and same number of turns, i'd still put each on a separate diode block
16:46 katsmeow-afk for the cost of one additional block, i can use cheaper blocks and dissipate more power and not worry about winding irregularities
16:48 katsmeow-afk i once saw two gennies paralleled badly, they both went from zero throttle to full throttle as they alternately hogged the load and fought each other, the cure was to split the load and separate the two gennies
16:50 rue_shop its ridgid abs
16:50 katsmeow-afk o
16:50 rue_shop we use it here for sewer pipe
16:50 rue_shop cellular core
16:51 Tom_itx that crap gave me grief this year
16:51 rue_shop ?
16:51 Tom_itx broke just below the joints in 3 places
16:51 Tom_itx cost me a days worth of play
16:51 rue_shop they cant seem to get it right in the usa, which is why I think they dont use it
16:51 katsmeow-afk "below the joints" ?
16:52 rue_shop we use it all the time up here and never have problems
16:52 Tom_itx kat, yes
16:52 Tom_itx snapped off clean
16:52 katsmeow-afk oh, ouch
16:52 Tom_itx with strap supports under it
16:52 Tom_itx no idea why
16:52 tsmeow-afk doesn't ei
16:53 Tom_itx had to cut out the sheetrock to get to it
16:53 rue_shop .168" thick
16:54 katsmeow-afk biggest problems i have with abs is it cold flows worse than pvc, and it's flexiness is so bad you can see it change dia with difefrent pressures, making it real easy to work rocks into it when buried
16:55 rue_shop I have a bedhead that uses a bunch of half-circle bent pipe I'm gonna try a mockup of the gyro cage with
16:55 katsmeow-afk it's great for coiling long temp lines on the ground, or drains above gnd,,, but i haven't used it at all in forever
16:55 rue_shop this is black cellular core ABS
16:55 rue_shop its not what your thinking, I'm sure of that
16:55 katsmeow-afk ok
16:55 rue_shop we never use it for anything presurized
16:55 Tom_itx i have some rue
16:55 rue_shop ok
16:55 Tom_itx no drain waste and vent
16:56 rue_shop yea
16:56 rue_shop (on)
16:56 Tom_itx that too
16:56 rue_shop there are so many things I can work on,
16:56 e_shop sits and thinks of all the wonderfull things he ca
16:57 katsmeow-afk i saw a site they had to dig up (it was only 3inches deep) and replace pipe every year from a combo of pressure changes and humans walking on it, kept getting punctured by rocks
16:57 rue_shop here , if its burried, it has to be atleast 18" down
16:57 rue_shop ABS MAX
16:57 rue_shop er min
16:57 rue_shop typical is 24"
16:57 tsmeow-afk ponders ceiling fans,,, not cause the air up there is better when fanned down here, but just to put the fans out of the
16:58 rue_shop except they converted it to metric and nobody really knows how far it is anymore
16:58 katsmeow-afk "it was 24 inches, but now it's metric, so it may be *way* down there, better get the biggest trackhoe you can"
16:59 rue_shop haha I forgot to get the pipe to make the bumpers for the new mowerbot
16:59 katsmeow-afk "but you said it was 1000mm deep!"
17:00 rue_shop we have a lot of mountians with exposed bedrock, that gets interesting
17:00 rue_shop you have to cast 12" of concrete over the line
17:01 katsmeow-afk the ole expensive conversions problems: i said deploy the parachute one MILE up, not one METER up
17:02 Tom_itx kat, heat rises so in the winter live on the celing and in the winter live on the floor
17:02 katsmeow-afk 12" of concrete over abs pipe sounds too pricey
17:02 Tom_itx err summer*
17:02 katsmeow-afk Tom, not with this insulation, there's no temperature gradient unlessi make one intentionally
17:03 katsmeow-afk cept upstairs, where thres's essentially no insulation
17:03 Tom_itx i don't know whether to trace the limit switch problem or wait until i move all the electronics to the box
17:03 katsmeow-afk my floors don't feel cold to touch in winter
17:08 Tom_itx the limits work until i plug in the big psu then they error
17:08 Tom_itx the v going to them is off the mesa card which measures 3.2v
17:09 Tom_itx everything else works fine
17:09 rue_shop 8-| why does this hammering towards my crotch thing seem so difficult to grasp! I thought I learned this last time!
17:09 Tom_itx i think they are 5v tolerant inputs
17:11 katsmeow-afk need more warning lables, rue
17:12 katsmeow-afk Tom, i dunno the electrical characteristics of the system
17:12 Tom_itx it's kinda srung out all over
17:12 katsmeow-afk how do you even have power to the limits if the psu is not connected?
17:13 Tom_itx it's coming off the mesa card which is powered from the pc usb
17:13 Tom_itx for now
17:13 katsmeow-afk oooooooooooooooooooooooooooooooooooooooooo
17:13 Tom_itx i haven't wired in the 5v on the main one yet
17:14 katsmeow-afk get thee a surge protector plug strip, plug the puter, and all the other mill stuff, into the same power strip
17:14 katsmeow-afk consider optical isolation
17:14 Tom_itx it's all isolated
17:15 Tom_itx well all but the switches
17:15 Tom_itx it comes off the port that i didn't buffer yet
17:15 katsmeow-afk the limits are optically ioslated from the usb port? and the puter is optically isolated from the stepper drivers?
17:15 Tom_itx i ran outta room on the first one
17:16 Tom_itx i'd have to check
17:16 Tom_itx most of the io on the card are isolated
17:17 katsmeow-afk usb is lvds, it would be easy for a 1/2 volt noise on a line to be interpreted as the opposite polarity,, or blow the usb port
17:19 tsmeow-afk needs to go more afk for a while, too away to r
17:21 Tom_itx it's just pulling power from it, not using the port
17:27 rue_shop so, to butt weld these 2 pipes, I think you said I split another peice of pipe and cram it in the inside
17:27 rue_shop do I have to take the paint off it?
17:28 Tom_itx :/
17:38 e_shop gue
17:38 Tom_itx do you leave it in, weld it in place or take it out?
17:39 Tom_itx i would clean it
17:58 rue_shop well its a ring
17:59 rue_shop so getting a peice of split pipe out of the junctions is gonna be a ****
17:59 rue_shop *
17:59 rue_shop yay, its a steel ring!
18:00 e_shop dubbs this mockup se
18:02 Tom_itx you should drill a hole on each pipe and weld it thru the hole then
18:02 Tom_itx so it doesn't rattle around in there
18:29 rue_shop I'm gonna assume that some part of welding the seam over it, it get stuck in\
18:30 Tom_itx you're in control of that
18:42 rue_shop butt welding pipe rings sucks
18:43 rue_shop and these rings are only like 3' dia
18:53 rue_shop I have to say, this 'maker' thing has really got me putting things togethor
18:53 rue_shop esp with the perspective that its art
18:53 rue_shop I mean, do we not inflict our artistic judgement into the things we make
18:54 rue_shop do we not tweek traces for hours upon hours to get them to look just the way we want?
18:54 rue_shop hmm
18:55 rue_shop when you reduce it down to 'maker' it all becoems so nice and simple, its not someone who makes robots or kinematic art or sculptures, its a person who is a maker.
19:19 zhanx http://tinypic.com/r/4ruzcz/6
19:54 rue_mohr I see
19:54 rue_mohr a few dvd's a tupperware container, and a pingpong ball
19:54 rue_mohr you?
19:56 Tom_itx sonar
20:00 ace4016 omg, Aquaman?!
20:04 zhanx its got servo's and a uC in there also, and that is the cd case
20:08 Tom_itx z use your cnc much yet?
20:08 zhanx not lately
20:39 rue_shop hmmm
20:44 Tom_itx http://www.youtube.com/watch?v=ferjLqbB0WE
20:48 zhanx i wonder if i should stop the backup, it started now....
20:55 zhanx rue_shop: what projects do you make with kids?
20:58 rue_shop no kids this weekend
20:59 rue_shop the one phoned and cancled and the other didn't phone to say they were comming
20:59 rue_shop I have a pipe mockup of the mecha
20:59 rue_shop so THATS how big a 12' mecha is...
21:02 zhanx pics or it didn't happen
21:03 zhanx and i asked what projects you do, not if they showed up.
21:05 rue_shop well I made some steel rings for a mockup of the gyro cage for controlling the mecha
21:05 rue_shop and I made this mockup
21:05 rue_shop I must have spent a lot of time doing nothing
21:06 rue_shop oh I did yard work
21:06 rue_shop I'll post the pics in a bit, I want to look at this for a while
21:07 rue_shop it really isn't that big...
21:09 rue_shop ok well, correction, when its laying down its not that big
21:10 rue_shop pretty intimmidating when you stand it up
21:11 rue_shop haha where did I just put my camera
21:14 zhanx got a circuit to power something on from a button push, with a power relay etc, on / off via a push button
21:28 rue_shop nice nice
21:29 rue_shop I'v been accepted into the vancouver maker faire
21:29 rue_shop that might be a good thing
21:29 Tom_itx might keep you inspired
21:31 rue_mohr !seen solarnrg
21:31 tobbor SolarNRG was last seen in #robotics on May 20 07:24 2012
21:31 rue_mohr he must be dead
21:33 rue_mohr !assist projects/smelter
21:33 tobbor Possibly http://eds.dyndns.org/~ircjunk/projects/smelter
21:33 rue_mohr http://eds.dyndns.org/~ircjunk/projects/smelter/p1030995.jpg
21:34 Tom_itx do you prop the other end on a bucket to pour?
21:35 rue_mohr :( only when there is nobody to play with
21:35 rue_mohr !assist robots/mowerbot2
21:35 tobbor Possibly http://eds.dyndns.org/~ircjunk/robots/mowerbot2
21:35 rue_mohr http://eds.dyndns.org/~ircjunk/robots/mowerbot2/p1040001.jpg
21:35 Tom_itx how do you tip it?
21:35 rue_mohr http://eds.dyndns.org/~ircjunk/robots/mowerbot2/p1040007.jpg
21:35 rue_mohr carefully
21:35 rue_mohr esp cause I was in sandles
21:36 rue_mohr those two are the rotation encoder for the new mowerbot castor
21:36 rue_mohr the phasing is bad, but its enough to get direction
21:36 Tom_itx needs a bit more phase shift
21:36 rue_mohr I cant adjust it
21:36 rue_mohr cheap mouse parts
21:36 Tom_itx oh
21:36 rue_mohr I tried
21:38 Tom_itx i wanna go play with the mill more but i'm too tired
21:39 rue_mohr !assist robots/sparrow1/
21:39 tobbor Possibly http://eds.dyndns.org/~ircjunk/robots/sparrow1/
21:39 rue_mohr http://eds.dyndns.org/~ircjunk/robots/sparrow1/p1040009.jpg <- ring for mockup gyro cage
21:40 rue_mohr http://eds.dyndns.org/~ircjunk/robots/sparrow1/p1040010.jpg <-- my pipe buttwelding sucks
21:40 rue_mohr http://eds.dyndns.org/~ircjunk/robots/sparrow1/p1040015.jpg <-- it really aint so big laying down
21:40 rue_mohr http://eds.dyndns.org/~ircjunk/robots/sparrow1/p1040018.jpg <-- significantly larger looking when standing up
21:40 rue_mohr but still, its not that big a robot
21:41 rue_mohr http://eds.dyndns.org/~ircjunk/robots/sparrow1/p1040020.jpg <-- ring set for gyro cage mockup
21:42 rue_mohr zhanx, ?
21:42 zhanx no its not
21:42 rue_mohr whats not?
21:42 rue_mohr whats not what?
21:42 zhanx big
21:42 zhanx your robot mock up
21:43 rue_mohr yea, its gonna be a bit of a challange to get all the gera on a frame that size
21:43 zhanx tomorrow i am firing up the cnc to do a test cutting of my marketing robot
21:43 zhanx gonna try to compete with the 3pi robot
21:45 zhanx after that i am making a ball bot with a gyro in it and a delta bot
23:15 katsmeow-afk .
23:37 katsmeow-afk In a Class-A, however, the ripple is at a maximum whenever the amp is switched on. If the ripple current is at the maximum for the capacitor, the life expectancy would be 2000 hours (for the normal types). This equates to a life of less than 2 years if the amp is used for 3 hours a day.
23:38 katsmeow-afk Remember that large capacitor values will have a smaller surface area per unit capacitance than smaller ones, so the use of multiple small caps instead of a single large component can be beneficial. There is more surface area, the ESR will be lower, ripple current rating higher, and the combination will most often be cheaper as well.
23:40 katsmeow-afk It is worth pointing out that historically, filter capacitors are the number one cause of power supply failure. This is almost always because of the effects of temperature and ripple current, and close attention to this is very much worth your while.