#robotics Logs

Feb 24 2014

01:30 rue_house output filter cap fixed it
01:30 rue_house I managed to solder it to a peice of veroboard and have it still work after
01:31 rue_house I lost my toothpaste
01:31 rue_house I forgot to do the kitty litter
01:34 rue_house and I forgot to shave
01:34 rue_house and I'm late for bed
01:59 rue_house why is it cheaper to make a 16 bit dac than to buy one?
02:23 zap0 says who?
02:28 rue_house why are DAC chips so stupidly expensive?
02:28 rue_house $19 for 10 bits?????
02:28 rue_house wtf?
02:28 rue_house dk wants $8.50 for 16 bits
02:32 sherlock supply and demand
02:33 sherlock or something
09:18 rue_house yoru saying they cant build DACs cast enough?
09:18 rue_house seriously, i can make a dac out of discretes for a fraction of the price of a chip
09:40 rue_house so I just noticed that synchronous smps can only be done with continious current converters
09:46 rue_house a 16 bit R-2R would take... 32 smt resistors, 2 74HC595, and maybe a rail to rail opamp
10:35 GuShH_ rue_house: you can't just make a discrete R-2R specially 16 bit without laser trimming the resistors
10:35 GuShH_ otherwise you'll get massive glitches
10:35 rue_house hey look! china has "5% precision" resistors!
10:35 GuShH_ which you could try to compensate with an LUT but you'd be spending more time - and money - than using a proper DAC
10:35 GuShH_ you need under 0.1% at 16 bit for meaningful results
10:36 rue_house I'm sure an R-2R wont have more than 1 lsb error
10:36 GuShH_ even at 8 bits you'll see what I mean
10:36 rue_house ?
10:36 GuShH_ furthest I'd go is 4 bits discrete
10:36 rue_house I did this before
10:36 rue_house I did 8 bit
10:36 rue_house came out fine
10:36 GuShH_ and you probably didn't plot the curve
10:38 GuShH_ no, came out fine is not acceptable, that's not a scientific method either
10:39 rue_house I ran a ramp and scoped it
10:39 rue_house it was a fine slope
10:39 rue_house dumb luck?
10:39 GuShH_ first of all you'll have a massive glitch at the crossover point, furthermore the loose tolerances will make the output rather useless for anything other than "it works"
10:40 rue_house what else matters?
10:40 GuShH_ a perfect sinewave LUT will look jiggly and distorted
10:40 rue_house if it works, it work?
10:40 rue_house ^s
10:40 GuShH_ yes I have done it as well, but I have also probed with the scope as I fed it a linear ramp, sinewave, etc. LUTs
10:40 rue_house but if a ramp seq comes out linear, what else is there?
10:40 GuShH_ I might have pictures in one of the bad hdd images somewhere
10:40 ShH_ is just highly upset at the "neighbo
10:40 GuShH_ perhaps you didn't see it
10:40 GuShH_ far back enough even turds look edible
10:41 rue_house the USA neighbour or closer to home?
10:41 GuShH_ you really do need a spectrum analyzer to see what I mean
10:41 GuShH_ errr one right next to my house
10:41 rue_house ah
10:41 rue_house are you talking about switching glitches between samples?
10:41 GuShH_ they are trying to move the fence 38CM to my side, because they claim it's "wrong" I took pictures, told them they need to bring in the surveyor, etc. and we all have to be there and they have to use calibrated devices and they have to be professionals
10:42 GuShH_ but he just went ahead and put his wetbacks to take out the fencing, naturally I'm upset and I will shoot any trespassers.
10:42 e_house stops a second to think about the impracticality of 16 bits of precision on a 0-30V power supply... but carries on an
10:42 GuShH_ it's private property I don't know if they're trying to get in and steal from me, it's only natural.
10:43 rue_house put a fence up on your side
10:43 GuShH_ furthermore I don't see any surveyor lines or guidelines (whatever you call them, the damn string they put on to mark the division before fencing goes on)
10:43 rue_house or was that your fence
10:43 GuShH_ we had 2
10:43 GuShH_ that's common here, leave a tiny gap in the center if both parties agree to make a wall
10:43 GuShH_ otherwise that's how it is, 2 fences and a tiny gap
10:43 rue_house there typically done with square steel pegs at the property corners
10:43 GuShH_ they want to move it over because they claim it's their space, I don't see any paperwork proving it
10:43 GuShH_ rue_house: we had concrete posts and fencing
10:43 GuShH_ they broke one of the posts
10:44 GuShH_ and removed the older fence which had wooden posts
10:44 GuShH_ without my permission
10:44 GuShH_ they also got rid of the vegetation that covered the fencing, now I gotta see their shitty poolhouse and their falling-apart house
10:44 GuShH_ I'm not the only one upset the other neighbour complained as well for the same reason
10:44 rue_house hmm, south americal is not a place north america thinks of as haing sturdy laws
10:44 GuShH_ rue_house: they think they can get away with it
10:45 rue_house proce they cant
10:45 GuShH_ I took pics before
10:45 GuShH_ I'm taking pics all the time
10:45 rue_house prove they cant, get a surveyor in, sue them for the resulting costs :)
10:45 GuShH_ they have to pay for it
10:45 rue_house and for rebuilding the fence
10:45 GuShH_ because they are claiming
10:45 GuShH_ not me.
10:45 rue_house good show
10:46 GuShH_ sure but I will lose in the end, you always do with lawyers
10:46 GuShH_ you know who my lawyer is? <grabs crotch> that's the lawyer.
10:46 rue_house :( back in the day, I got a 10000 pcs 1206 resistor reel for $17
10:46 GuShH_ and now?
10:46 rue_house looks like, today, i can get 5000pcs for $18
10:46 GuShH_ I called the surveyor and he claims there's almost no way it was done wrong 40 years ago
10:46 GuShH_ and specially because they are reinforced concrete posts
10:47 rue_house GuShH_, you can have them "re-cut" the lines,
10:47 rue_house put in markers
10:47 GuShH_ that's what this guy should have done
10:47 GuShH_ and marked
10:47 GuShH_ I don't see lines, marks, nothing
10:47 GuShH_ they are acting on a whim
10:47 GuShH_ and I will put and end to it one way or another.
10:47 rue_house get the surveyor in to mark it out
10:47 rue_house otherwise you will end up with a fence in your yard
10:48 rue_house if like kat, WAAAY in your yard
10:48 GuShH_ yes but he will pay for it because it's his claim, otherwise if we go to court it's going to be a 2 year nightmare
10:48 GuShH_ rue_house: but kat seems overpowered by anyone
10:48 rue_house yaknow, I cant even FIND a reel of 10000
10:48 GuShH_ I can't even go out today, not knowing what they were trying to do
10:48 GuShH_ they thought nobody was around
10:49 GuShH_ that's low.
10:49 GuShH_ that's some devious shit.
10:49 rue_house they already took the fence down, what else can they do?
10:49 GuShH_ install a new one IN MY PROPERTY
10:49 GuShH_ you can't do that, you can't even touch a fence
10:49 rue_house or is that one of the areas where if you leave your house its free to claim by anything
10:49 GuShH_ without the consent of the other person
10:50 GuShH_ it's illegal
10:50 GuShH_ rue_house: that's more or less the case in most countries though
10:50 rue_house if they put up a fence in your yard, they just gave you all that material
10:50 GuShH_ it happened to my folk's weekend home
10:50 GuShH_ 3 times
10:50 GuShH_ next time I will make them go poof.
10:51 GuShH_ rue_house: irrelevant, the cost of the land they'd be stealing is far greater than the cost of the materials or labour
10:51 GuShH_ hence their attempt.
10:51 GuShH_ but you gotta be fucking nuts to attempt this for a few square meters you'll never use
10:51 rue_house how far over are they moving it?
10:51 GuShH_ and they are probably running on the assumption of a poorly interpreted blueprint or readout
10:51 GuShH_ 38 cm in theory, but that's not the point they should not touch anything without paperwork and surveying first
10:52 GuShH_ 38cm by 50 or 55 meters long
10:52 rue_house if you can afford to, get the surveyor over
10:52 GuShH_ they'll just hand me a paper with measurements and it won't be good for shit other than a possible court case
10:52 GuShH_ point being this is done before you touch anything
10:52 rue_house no you can ask the surveyor to mark the lines
10:52 GuShH_ you first TALK to the property owner
10:53 GuShH_ so they are trying to claim 200M2 or so, even 1M2 is enough for me to get upset over.
10:53 GuShH_ I was going to get a rangefinder but what's the point they won't obey any results I show them
10:54 GuShH_ and the surveyor told me I could try to measure it myself but they haven't listened so far, they won't after the fact either.
10:54 GuShH_ since they claim their property extends 38cm to my side, they should survey and mark it, they haven't
10:54 GuShH_ which makes it even more illegal.
10:54 rue_house GuShH_, are the owners locals or forigners
10:54 GuShH_ I don't know I assume Chilean
10:54 GuShH_ they are always moving the border between chile and argentina
10:54 GuShH_ I swear to god they are born with a "low space" complex in their mind
10:54 GuShH_ they need to take over lands to feel better.
10:55 rue_house start putting up a fence blatently on their side
10:55 GuShH_ just look at a map of Chile to see what I mean
10:55 rue_house use some pop bottles and string :)
10:55 GuShH_ they are born in a skinny turd.
10:55 GuShH_ cattle fence came to mind, but too much vegetation.
10:55 GuShH_ and pliers take care of those
10:55 GuShH_ snip, snip, no more HV
10:56 rue_house hah, snip their power lines and make a fence out of that
10:56 GuShH_ actually after the storm the post carrying their lines fell onto their property
10:56 GuShH_ if I wanted to be malicious I could do other things, but that's not me.
10:56 rue_house :) I should make a rule about presenting problems you dont want help with
10:56 GuShH_ feuds only end up one way.
10:57 GuShH_ rue_house: what kind of help? I already called a surveyor, the one the seller used when we bought the place
10:57 rue_house I found a roll for $14
10:57 GuShH_ which is adding even more insult to injury, when you buy a place it has to be surveyed first
10:57 GuShH_ to see if the dimensions match
10:57 GuShH_ so clearly it's been done many times, now suddenly this guy claims there's an error out of the blue and shows no paperwork to prove it
10:57 GuShH_ gives me no surveyor phone to call either
10:58 GuShH_ and for all I know his brother will answer and pretend to be one.
10:58 rue_house when they sell the place and the fence is 1m in your side, do they have to correct it?
10:58 GuShH_ no I won't let it happen
10:58 rue_house there is nothing you can do about it
10:58 rue_house you kinda just said so
10:58 GuShH_ I'll go guns blasting if I have to, a couple shots on the ground might make them think twice, or just call the cops and escalate. see there's no easy solution
10:58 GuShH_ maybe cyanide in their water tank would be best for all of humanity
10:59 rue_house do cops show up to places there if there is gunfire?
10:59 rue_house they do here
10:59 GuShH_ you can't reason with dipshits
10:59 GuShH_ rue_house: only if it's reported
10:59 GuShH_ there's no active scanning system
10:59 GuShH_ ie no mic arrays
11:00 rue_house you should shoot a few rounds and report it, as maybe comming from your neighbours place
11:00 rue_house :)
11:00 GuShH_ I reported suspicious behavior last week, an old car and 3-4 colombian or puertorican teens throwing rocks and banging shit around outside
11:00 GuShH_ cops arrived 10 minutes later
11:01 rue_house if a seller has 112k sales and is at 99.3% I can prolly trust them
11:01 GuShH_ rue_house: that's just doing what he's doing, lying
11:01 GuShH_ you could
11:01 GuShH_ what could possibly go wrong :p
11:02 rue_house if I buy via alibaba, its tracked
11:02 rue_house and its escrow, so they make sure I get it
11:02 GuShH_ good
11:02 rue_house and aliexpress' roll of 5k is $14.60
11:02 rue_house vs ebay at $13.38
11:02 GuShH_ no local surplus store?
11:03 rue_house hell no
11:03 GuShH_ that's what everyone in the US asks me... assholes
11:03 GuShH_ god damn it, I'm tired of hearing that question
11:03 rue_house I think I have more component stock than anyone around here
11:04 rue_house let me measure...
11:06 GuShH_ there are so many branches bushes and crap I can't discern the line on the pictures I took las time
11:06 GuShH_ but you can see the broken post, which wasn't broken before
11:06 GuShH_ and today they began to remove 'em, so we're taking pics again
11:06 GuShH_ might want to take pics of the dude doing it, his face, just so he feels uneasy doing it.
11:07 rue_house my guess is 40km to the nearest electronics component store
11:07 GuShH_ rue_house: there could be someone even more nuts than you
11:07 GuShH_ and have even more components!
11:07 rue_house could be, not too likley
11:07 GuShH_ hmm yeah I'm about 40 to the closest but it's also the one with the least parts
11:07 GuShH_ the proper ones are at 60-80
11:08 GuShH_ so for me, I try to get by with what I have in stock
11:08 rue_house there is a ferry int eh middle that adds $100
11:08 GuShH_ since it's a long trip for a friggin resistor
11:08 GuShH_ I have tolls, going both ways :p
11:08 GuShH_ NO SURPLUS STORES HUH? TOO BAD <eats bacon>
11:10 rue_house and china delivers
11:10 rue_house the postbox is almost just across the street, its within pajama distance
11:12 rue_house but the alibaba store is at 701 sales and only has 98.6% feedback
11:12 GuShH_ darn as luck has it the picture of the bleed solenoid valve on the compressor came out of focus
11:12 GuShH_ I might want to add a 90� elbow
11:13 rue_house oo almost 5 reports of no delivery
11:16 rue_house normally open solinoid before the check valve tried to the motor power?
13:08 GuShH_ rue_house: net splits?
15:14 rue_house dunno
15:14 rue_house I turned off all the messages
15:51 rue_house it looks like nobody has ever used an LM386 to drive a mosfet gate
19:24 rue_house now the power is out-out
19:29 GuShH_ rue_house: branch / tree did it's thing?
19:44 rue_house something
19:44 rue_house I'm gonna go look up/down road and see if I can spot anything for them
20:10 rue_house siphoned a can of gas from the truck
20:10 rue_house should hold me a while
20:10 rue_house dont know why the gen keep stalling
20:18 Tom_itx carb
20:18 Tom_itx same ole sucky carb?
20:19 Tom_itx mine started surging, put a kit in it, tuned it all up... still surged
20:19 Tom_itx traded it for a new one
21:06 GuShH_ rue_another: there?
21:07 Tom_itx bet his power is going
21:08 MrCurious anyone seen GargantuaSauce_ talk lately?
21:10 rue_house it seems that the gas filter was adding too much restriction
21:10 GuShH_ time to replace it
21:10 GuShH_ probably clogged up with gunk
21:10 rue_house I removed it for now
21:10 GuShH_ rue_house: the banjo screw for the big gears stripped..
21:11 GuShH_ it was mild steel...
21:11 rue_house how did you strip that?
21:11 GuShH_ I'm wondering whether I should try to fix the part or make one from scratch
21:11 GuShH_ just flipped the gears to go back to metric
21:11 GuShH_ and I adjusted, it was wobbly, so I adjusted some more
21:11 GuShH_ it stripped.
21:11 GuShH_ same way the compound bolts stripped, they are made out of butter and undersized
21:12 rue_house the T nut stripped?
21:12 GuShH_ the nut seems ok but I had to put a tap on it, works fine but it's not top notch
21:12 GuShH_ no, the bolt
21:12 GuShH_ I'll get a pic
21:12 GuShH_ the bolt that acts as the shaft
21:12 GuShH_ with the oiler
21:12 GuShH_ should be M8 they used M6...
21:13 MrCurious M6!!!!!!
21:13 rue_house this is where I start to worry about not having a level sensor on the genorator fuel tank
21:13 GuShH_ theres no reason why they used M6 for it instead of M8 or M10 because the stock is good for up to M10... and they can mill the slot bigger and the nut -as is- could be M8 safely
21:13 GuShH_ rue_house: aux tank
21:14 rue_house its a boat tank
21:14 rue_house I should put a 24 hr tank in
21:14 GuShH_ how big would that be
21:14 GuShH_ hmm so now I can't thread
21:14 GuShH_ I could turn the stripped M6 portion down, drill 5mm, tap... but I don't have a blind tap for M6, only half conical
21:15 GuShH_ see I could insert M6 stainless and loctite it in place, plus friction fit
21:15 GuShH_ or I could try to make the whole part from square steel stock... but how do I remove the oiler insert?
21:17 GuShH_ rue_house: http://gushh.net/tmp/p_20140224_235109f.jpg
21:18 GuShH_ sorry for the shitty quality, taken with a tablet
21:18 GuShH_ on low light!
21:18 rue_house hah
21:18 GuShH_ tapped the nut, could still work fine but I would try to harden it first
21:18 rue_house why did you even tighten that?
21:18 GuShH_ because you have to flip the 2 gears around if you switch from imperial to metric or vice versa
21:19 GuShH_ 127 teeth on one side, 120 on the other
21:19 GuShH_ I had to cut 1.25mm and then go to 28tpi, meant having to flip them over twice (so I could go back to metric)
21:19 GuShH_ I've probably done that about 10-15 times since I have itand now it stripped
21:19 Tom_itx GuShH_ what's this you're working on?
21:19 rue_house but you dont need to tighten it much at all...
21:19 GuShH_ Tom_itx: that's part of the lathe banjo
21:19 GuShH_ rue_house: it was too wobbly!
21:20 GuShH_ and I didn't need much force to strip the compound bolts either, they are mild steel
21:20 GuShH_ I believe they use rebar for these, seriously.
21:21 GuShH_ it's also poorly designed the nut should be twice as thick
21:21 GuShH_ so twice more thread engagement would be allowed
21:21 rue_house make anew one from a larger grade 5
21:21 GuShH_ and, M8 at least.... it's poorly made
21:21 GuShH_ I have grade 8 on similar sizes, but I have no mill to turn the head square
21:21 GuShH_ plus I don't have oilers that small (it's on the flat side)
21:22 GuShH_ it's a goner anyway might as well try to tap and insert a threaded M6 rod for now
21:22 GuShH_ the banjo is very annoying, the nut always falls off when you are to flip the gears
21:23 GuShH_ rue_house: first mod on these lathes should be "replace anything with a thread"
21:23 GuShH_ http://gushh.net/tmp/p_20140224_235139f.jpg
21:23 GuShH_ Tom_itx: any clue on how to remove the oiler?
21:24 GuShH_ I can make a new part... but I can't source those oilers and I certainly don't intend to make one from scratch
21:24 GuShH_ plus they use conical springs and they're fiddly
21:24 GuShH_ rue_house: also the gears are not bushed at all... just raw iron...
21:25 GuShH_ you can see the black oxide stripped off due to friction
21:25 GuShH_ (and that's in part why it was a bit wobbly)
21:26 GuShH_ not a nice fit anymore
21:27 rue_house dont knwo why it stalled that time
21:27 GuShH_ hrmm is it a chinese genset? heh
21:27 ShH_ hugs his japanese ge
21:27 GuShH_ hrmm square head .. I would need to fit the 4 jaw chuck... sigh
21:29 rue_house done milling on it yet
21:29 rue_house ?
21:29 Tom_itx oiler?
21:29 GuShH_ don't have a milling vise for the lathe
21:29 GuShH_ too expensive
21:29 GuShH_ Tom_itx : oiler insert
21:29 GuShH_ what are they called?
21:29 rue_house milling on the lathe
21:29 GuShH_ rue_house: no. I don't have a milling vise.
21:30 GuShH_ nor collets
21:30 Tom_itx not following i guess
21:30 GuShH_ Tom_itx: http://gushh.net/tmp/p_20140224_235139f.jpg
21:30 Tom_itx the end of the square block?
21:30 GuShH_ yes
21:30 rue_house damit
21:30 GuShH_ that's an oiling port
21:30 Tom_itx is it hollow?
21:30 Tom_itx do you need to keep it?
21:31 GuShH_ you press the ball bearing with your oiler and it allows you to squirt the oil inside, then it keeps it shut so no gunk gets in
21:31 GuShH_ it's what keeps the shaft lubricated
21:31 GuShH_ works on centrifugal force
21:31 GuShH_ there's a hole in the middle portion of the shaft, it's just not visible on those pics
21:31 Tom_itx can't tell from the pic, too much shadows
21:32 GuShH_ bah I said "sorry for the bad pics" already :p
21:36 GuShH_ rue_another: stalled again?
21:37 GuShH_ Tom_itx: best I can do right now http://gushh.net/tmp/dscn5157f.jpg -- http://gushh.net/tmp/dscn5154f.jpg
21:38 GuShH_ you think it somehow cross-threaded?
21:38 Tom_itx is the thread hollow?
21:38 Tom_itx it's just shit material
21:38 Tom_itx looks pulled even
21:38 Tom_itx not sideways
21:38 GuShH_ thread is not hollow, the other side is half way hollow for the oil opening
21:39 Tom_itx you need to get what done?
21:39 ShH_ keeps thinking they make these out of r
21:39 GuShH_ either cut the stripped M6, bore m5 hole and thread M6 female to add a stainless M6 threaded rod in there, or... make the whole thing from scratch
21:39 Tom_itx rebar is probably higher quality
21:39 GuShH_ err by M5 I meant 5mm
21:39 GuShH_ haha
21:40 GuShH_ I was cutting some free machining steel today, it was wonderful compared to mild steel
21:40 Tom_itx you'd be better off starting over
21:40 Tom_itx then case harden it
21:40 GuShH_ you have too much confidence on me...
21:40 Tom_itx heat it cherry and drop it in oil
21:40 GuShH_ I will try to case harden whatever is left from the T nut
21:41 GuShH_ these are most likely quenched in oil, due to the black oxide.. unless there's a cheaper way to get that finish
21:43 GuShH_ Tom_itx: if I do start from scratch, how on earth am I going to remove the oil insert
21:43 GuShH_ I doubt 120PSI will make it pop out
21:43 Tom_itx can you put a stud on the mating part and tap that?
21:43 GuShH_ I could try
21:44 Tom_itx that might be the easiest thing
21:44 GuShH_ If I had these oiler thingies I wouldn't think twice about making it all from scratch, it's not a hard part
21:44 Tom_itx yeah
21:46 GuShH_ But I understand why it's there and what it's doing, allowing a cushion of oil between the surfaces... without it I would need to constantly flood it with oil...
23:34 GuShH_ holy crap... 2 hours to turn the blank for that piece... all because I have no power feed now :(
23:37 GuShH_ the shaft fits perfectly, I think I'm a few mils shy from an interference fit, spins with slight resistance with oil in between the surfaces, but the idea is to let it hone itself with regular wear, brass would be ideal but I don't have any stock other than small hexagonals...
23:38 GuShH_ I'll probably just file a couple flats down for the head...
23:41 ShH_ doesn't like machining regular mild steel, it's gr