#robotics Logs
Sep 08 2014
#robotics Calendar
00:03 rue_shop3 1000 roms has always been enough for my projects
00:03 rue_shop3 yay! I finished the SS tig welding job for the kitchen sink
00:04 rue_shop3 awe, I didn't clean dust out of the server
00:04 rue_shop3 the drive is at 43c, maybe its good for 1 more day
00:10 rue_shop3 and I cast the pulley
00:11 rue_shop3 it didn't come out awesome, the lost foam thing isn't spectacular
00:11 rue_shop3 and I didn't quite make enough aluminum
00:38 rue_more goodbye world
00:42 adam789654123 hello rue_more
01:05 rue_house hi
01:07 adam789654123 what going on?
01:23 mrdata rue_house, a goldsmith friend of mine advises that the bentonite is not harmed from preheating it
01:23 mrdata and advises to add flux first, then molten aluminum
01:23 mrdata you need channels for gases to escape
01:24 mrdata and of course you must use excess, to fill those
01:24 mrdata after cooling, the sprue is cut off
01:26 mrdata https://en.wikipedia.org/wiki/Sprue_%28manufacturing%29
01:31 adam789654123 what are you using bentonite for?
01:47 mrdata adam789654123, mixed with sand, to make a mold for casting
01:47 mrdata so it's a binder, that will make a smooth barrier
01:54 adam789654123 hmmmm
01:54 adam789654123 so i guess clay with sand basically
01:55 mrdata yes
02:02 adam789654123 past my bedtime
02:02 adam789654123 interesting stuff though
02:08 __doc__ so I'm a complete robotics noob. I've got a need to control two stepper motors, one for a small rotating table and one for a rotating arm (both horizontally). Both very low torque and speed, but it needs to be fairly accurate, and I need to hook it up USB so I can drive it from my computer (which will need to some processing before issuing the next movement).
02:09 __doc__ (I'm assuming a stepper motor's the best choice for that kind of thing)
02:10 __doc__ I'm looking for pointers what hardware would best work for that.
02:12 mrdata steppers have good positional accuracy, but
02:13 mrdata __doc__, do you want these motors to rotate at a fixed rate?
02:13 mrdata or move to a particular position and stop?
02:14 __doc__ mrdata: ideally I'd rotate the table/arm by a set amount, stop and then my DSLR takes a snap
02:14 mrdata steppers are strongest torque when stopped
02:14 mrdata ok
02:14 mrdata seems like thats a good choice for motors
02:15 __doc__ so from what I understand I'll need a controller board, a driver the motors and some wiring
02:15 mrdata so for novice use, something like arduino with a stepper motor shield would do
02:15 __doc__ (driver board)
02:15 mrdata and you can get arduinos to hook up to usb iirc
02:16 __doc__ yeah there are some, but I'm a bit hazy on how modus works, is it like you load a program onto em trough USB, or do you control em trough USB?
02:17 __doc__ (I'm a programmer, so I have got no problem talking to some USB device, just wouldn't like to have to kick a compiler and program upload into gear everytime I want to issue commands to the motors)
02:23 __doc__ oh, it seems like you can interface with a program on the arduino trough usb
02:37 mrdata once the program is written and flashed to the microcontroller, you will be sending it positional commands instead of compiling, when you use it
02:37 __doc__ right
02:39 __doc__ so I'll need a stepper motor, a driver board, an arduino with a USB interface and a gearbox (I need steps smaller than 1.8°)
02:39 __doc__ and some sort of power supply
02:41 mrdata yep
02:41 mrdata sounds good
02:41 mrdata the microcontroller can power off usb but the motors need their own supply
02:41 __doc__ yeah
02:42 __doc__ so typically way you'd find the matching components is select a motor/gearbox you like and then find the driver and power supply I guess
02:42 mrdata right
02:43 mrdata though lots of stepper drivers are compatible with various motor voltages
02:43 __doc__ yeah
02:43 mrdata there are current limits on drivers; you will want to examine carefully
02:44 __doc__ jep
02:44 mrdata and get a motor/gearbox that is the right size for your needed torque
02:45 __doc__ yeah haven't calculated the torque, but stuff's going to move so slowly and be so lightweight, it's neglible
02:45 __doc__ (the arm just carries a LED, and the rotating table carries bits of paper and a small material sample)
02:46 mrdata i see
02:46 mrdata yeah, so small motors
02:47 mrdata well, i'm off to bed
02:47 mrdata good luck
02:47 __doc__ n8, thanks :)
02:53 __doc__ hmm, actually the best fit would probably be a CNC kit
02:53 __doc__ gets me the power supply, driver and bunch of steppers in one go
03:34 __doc__ hm, so an arduino shield would be the easiest way to interface steppers with the arduino board
03:37 __doc__ cool and the shield can feed off the external power of the arduino
03:37 __doc__ so no messing about with some dedicated power supply
11:14 applepi Hello all! :) Question: Has anyone here ever attempted to have a conveyor which adjusts in shape before? Something like this? http://imgur.com/VSd8nZy
11:16 applepi I'm an FTC mentor an my students have come up with an idea like this, but I worry they're going to run into issues with the belt no longer meshing with the rollers anymore once they've moved. I'm not much of a mechanical and none of the other mentors have much mechanical experience either, so I'm trying to figure out if I need to warn them off this path or not.
13:13 rumpelstiltskin hi
13:18 adam789654123 hello rumpelstiltskin
13:18 rumpelstiltskin hi
14:12 adam789654123 rumpelstiltskin: you still around?
14:12 rumpelstiltskin yes
14:16 rumpelstiltskin adam789654123: do you have some questions?
14:16 adam789654123 im trying to think of a good one
14:16 adam789654123 but all that i seem to have come up with, is, so you're into robotics huh?
14:16 rumpelstiltskin good question is a 50% of answer
14:16 rumpelstiltskin :) I am
14:17 adam789654123 im interested myself
14:17 adam789654123 but i havent built anything
14:17 adam789654123 have you built anything?
14:18 rumpelstiltskin yes
14:18 rumpelstiltskin not fully
14:18 rumpelstiltskin you know me actually
14:18 adam789654123 ohhh
14:18 adam789654123 from the story?
14:18 rumpelstiltskin I'm robotustra
14:18 adam789654123 ;)
14:18 adam789654123 ahhhh
14:18 adam789654123 hey
14:18 rumpelstiltskin I just tried this nick, but it's look like registered
14:19 rumpelstiltskin so, I just use it for some time
14:19 adam789654123 yeah
14:19 adam789654123 its memorable
14:19 rumpelstiltskin I build robot eyes, printed a torso and a head
14:19 rumpelstiltskin but didn't assemble yet
14:20 adam789654123 im thinking that i would probably get into electronics and use that as the vehicle for learning robotics
14:20 rumpelstiltskin need to make muscles, neck
14:20 adam789654123 but im interested in simple stuff
14:20 adam789654123 for now
14:20 adam789654123 like maybe gauges that integrate with electronic devices that conrol various devices
14:20 rumpelstiltskin first it should be a desire
14:20 adam789654123 but in simple ways
14:21 adam789654123 and it is
14:21 adam789654123 its something that intests me, not exclusively, but as something that goes with other things
14:21 adam789654123 that is interesting and usefull in context
14:21 rumpelstiltskin it should be a desire to kreate something definite, one saparate thing
14:21 rumpelstiltskin create*
14:21 adam789654123 ive just started studying Haskell
14:22 adam789654123 and im interested in mathematics
14:22 adam789654123 so that would be very usefull on the electronics and physics end of things
14:22 rumpelstiltskin so, may be encription?
14:22 adam789654123 interested, but not heavily now
14:23 adam789654123 but i did just see a great video on the Laurence Machine
14:23 adam789654123 last night
14:23 adam789654123 which was very interestig
14:23 rumpelstiltskin if you want to do something, just start from simple
14:23 adam789654123 it was the cypher for german high command
14:23 adam789654123 the cypher machine*
14:23 adam789654123 exactly
14:23 adam789654123 i agree
14:24 rumpelstiltskin like this https://www.youtube.com/watch?v=gEqghokSw9U
14:24 adam789654123 im working on stuff that i can understand as a bridge to understanding what i dont
14:24 adam789654123 it keeps me grounded
14:24 adam789654123 and it keeps me marching forward
14:25 rumpelstiltskin may be I'll make it one day for my kids
14:28 rumpelstiltskin adam789654123: did you make something in your life by hands more complex than just cutting paper?
14:30 adam789654123 the most complex things would be programs
14:30 adam789654123 that was an awsome link by the way
14:30 rumpelstiltskin unfortunately it's impossible to buy them online
14:30 rumpelstiltskin have to make them myself
14:31 adam789654123 i guess thats part of the fun though
14:32 rumpelstiltskin yeah
14:32 adam789654123 but ive never built anything comprable to my programs using the "electronic toolkit"
14:33 adam789654123 but eventually i want to
14:33 rumpelstiltskin what tools do you have for it?
14:33 adam789654123 none for electronics
14:33 rumpelstiltskin and where are you going to build it?
14:33 adam789654123 i would have to learn and collect the tools
14:33 rumpelstiltskin I mean hardware
14:34 rumpelstiltskin saws files
14:34 adam789654123 since im not even sure exactly what is worth having, im not sure where to get it
14:34 rumpelstiltskin hammer, drill, screwdriver
14:34 adam789654123 i have some basic stuff like that
14:34 rumpelstiltskin hardware store
14:34 adam789654123 ive done basic construction work
14:34 adam789654123 professionally
14:34 rumpelstiltskin it's enouph for beginning
14:35 adam789654123 but im very interested in using electronic sensors to control things
14:35 rumpelstiltskin buy arduino board and some servos
14:35 adam789654123 transducers and controlers
14:35 adam789654123 and play with them
14:35 adam789654123 more to do theoretical work
14:35 adam789654123 then to make something that i need
14:35 rumpelstiltskin so, you can buy a simple robot kit
14:35 rumpelstiltskin and play with it
14:36 rumpelstiltskin it could have bumper sensor, IR sensor
14:36 adam789654123 so i might do something like that, but i was thinking that i should study electronics before getting into robotics
14:36 rumpelstiltskin no
14:36 adam789654123 really
14:36 adam789654123 ok
14:36 rumpelstiltskin thare are 2 types of ppl
14:37 adam789654123 my reasoning was that i would like to run the logic via various progamming paradigms
14:37 adam789654123 so i could play around with that
14:37 rumpelstiltskin if you know programming you already know discret electronics
14:37 adam789654123 with shuttling inforamion around the system
14:37 adam789654123 information*
14:37 adam789654123 yes, i agree
14:37 adam789654123 well put
14:37 rumpelstiltskin that's it
14:38 rumpelstiltskin start from arduino + leds, and jump to simple robot kit
14:38 rumpelstiltskin it's the simplest way to get into robotics
14:38 adam789654123 im thinking longer term because im so buisy now that i cant jump in
14:38 rumpelstiltskin after replace leds with servos
14:39 rumpelstiltskin and try some sensors
14:39 adam789654123 so i am thinkinking about say, 5 years from now
14:39 rumpelstiltskin and that's it
14:39 adam789654123 what would i like to be workking on
14:39 adam789654123 and working around that
14:39 adam789654123 and moving slowly in that direction
14:39 adam789654123 while i build my skills in areas that will be useful
14:40 rumpelstiltskin adam789654123: if you think that you'll be in a coffin in 100 years - it's a good reason why not to start robotics
14:40 adam789654123 hopefully not in 5 though
14:40 adam789654123 for example, i am studying basic geometry now
14:40 rumpelstiltskin stob thinking, pull up your lazy ass and DO SOMETHING finally
14:41 adam789654123 this seems VERY valuable for robotics
14:41 adam789654123 as you can build relational constructs that have geometric properties
14:41 rumpelstiltskin can you move things with a power of your mind?
14:41 adam789654123 its not hard to imagige the relationships acting in defined ways
14:42 rumpelstiltskin I mean real atoms
14:42 adam789654123 by means of my mind, i can move the contents of my mind, and by means of the contents of my mind, i can move real things
14:42 adam789654123 for example, the concept of leverage allows one to lift more then without it
14:42 rumpelstiltskin adam789654123: it was sarcasm :(
14:42 adam789654123 o
14:43 adam789654123 its hard to sense on irc
14:43 adam789654123 XD
14:43 rumpelstiltskin can you buy electronics from internet?
14:48 adam789654123 yes
14:48 adam789654123 but i want to start out REALLY REALLY simple
14:48 adam789654123 like maybe buying one of those soldering pots
14:48 adam789654123 and playing with old electronics
14:49 rumpelstiltskin beware, old electronics can swallow you
14:49 adam789654123 what do you mean?
14:49 adam789654123 your energy?
14:49 rumpelstiltskin no
14:49 adam789654123 what do you mean?
14:49 rumpelstiltskin you'll not be able go to digital back
14:49 adam789654123 that is an interesting statement
14:50 adam789654123 ahhhh
14:50 adam789654123 ill not be learing digital?
14:50 adam789654123 is that what you mean?
14:50 adam789654123 ill be learing analog via old electronics?
14:50 rumpelstiltskin no, you'll like warm laps electronics more
14:50 adam789654123 i dont understan "warm laps"
14:50 rumpelstiltskin analog electronics is fun
14:51 adam789654123 yes
14:51 adam789654123 thats what i want to start with
14:51 adam789654123 for digital, im more interested in interfacing with functional languages
14:51 __doc__ Isn't it like, there's an elegance in analog electronics, and these days it's just mashing stuff together wildly and see if it can be coaxed to do something useful?
14:51 adam789654123 for example, integrating the AI techniques of lisp with analog
14:52 doc__ having no clue of analog whatsoever wholeheartedly embraces mashing stuff wildly toge
14:52 adam789654123 the both seem elquent to me
14:52 adam789654123 but i have a huge blindspot in analog
14:52 adam789654123 and its more connected to physics
14:52 adam789654123 as far as i can see
14:52 rumpelstiltskin start with this book: https://www.indiegogo.com/projects/arduino-basic-connections-the-book
14:53 adam789654123 where the concepts of digital seem very very simple
14:53 adam789654123 the concepts of analog seem much more subtle
14:53 rumpelstiltskin interfacing with functional languages is nealy inpossible
14:53 rumpelstiltskin impossible
14:54 adam789654123 i doubt that
14:54 rumpelstiltskin becuse FP is a spherical horse in vacuum
14:54 adam789654123 you just need the knowledge
14:54 adam789654123 but if you can get throug
14:54 adam789654123 but if you can get through a book like "lisp in small peices", you could integrate functional with analog
14:54 adam789654123 on the programming side anyway
14:54 rumpelstiltskin actually you don't need to interface that
14:55 rumpelstiltskin it's like merry you high reasoning with muscles action
14:55 rumpelstiltskin too many layers in between
14:56 adam789654123 maybe your right
14:56 adam789654123 but i cant see why that should be the case
14:59 adam789654123 besides, high reasoning can be used in constructing the routine to train muscles and how to nourish them
15:00 adam789654123 im not saying that i would be limited to this task
15:00 adam789654123 of this integration
15:00 rumpelstiltskin you are in the very beginning of this way
15:00 adam789654123 but it interests me
15:00 adam789654123 exactly
15:00 adam789654123 this is very true
15:00 adam789654123 but i see the path
15:01 rumpelstiltskin and this is tha very last problem yuo'll face with
15:02 rumpelstiltskin you'll spend about 5 years just to connect muscles and brain
15:02 adam789654123 sure
15:02 rumpelstiltskin and 1 month to write a code to self calibrate
15:02 adam789654123 haha
15:02 adam789654123 maybe
15:02 rumpelstiltskin I know what I'm talking about
15:03 adam789654123 in an abstract sense, that getting there the first time is many orders of magnitutes harder then repeating yourself
15:03 adam789654123 that to get there the first time takes much more effort
15:04 rumpelstiltskin I always do only 1-2 similar things, they are unique, so it's always slow
15:05 adam789654123 im just trying to keep the fire going on various things that im interested in
15:05 adam789654123 that way, when i feel intense, ive been collecting skills and tools and such
15:05 adam789654123 so its a sort of prepartation
15:05 adam789654123 for when inspiration strikes
15:07 adam789654123 like im studying Euclid's Elements now
15:07 adam789654123 and if im still not done with it in a few years, thats ok
15:07 adam789654123 as long as i make progress with it, and the stuff is interesting to me
15:08 adam789654123 and i build stuff and learn to think using simple geometrical cocepts
15:08 adam789654123 but its more the activity of engagement than the activity of being finished with something
15:08 adam789654123 like id rather thingk about something, and let it simmer, then hurry up and be done with it
15:09 adam789654123 certain things anyway
15:18 GargantuaSauce i would advise moderation in that approach
15:18 GargantuaSauce otherwise you'll end up like me with a several dozen page document of project summaries
15:19 GargantuaSauce which is a little bit imposing!
15:21 deshipu I've learned that if I can't get something to work in 3 days, I usually won't finish it.
15:22 adam789654123 im ok if nothing comes of it
15:22 adam789654123 i just enjoy it
15:22 deshipu it can take much longer to polish it, but I need to have something within those 3 days
15:28 adam789654123 its all usefull
15:28 adam789654123 if i do plan on continuing to work on something over a long period of time, i have to manage my intensity
15:29 adam789654123 i cant say, im gonna master math in the next year
15:29 adam789654123 i would burn out
15:29 adam789654123 some things require a slow burn interest, with occational spurts
18:50 rue_more I ant beleive it happened again
18:50 rue_more after I told myself I would be so carefull
18:50 rue_more I left somthing in the wrong place and ma got rid of it
19:44 rue_shop3 she didn't! I hid it good!
20:18 GuShH rue_shop3: https://www.youtube.com/watch?v=A1WFRC_ad2k
20:19 ShH pokes Tom
20:26 rue_more hahahaha
20:26 rue_more nice
22:01 rue_house RifRaf, whats up
22:01 rue_house hows work?
22:03 rue_house ah, fix the bedding, this is a good goal
22:04 rue_house I think I was gonna pour the other rolloer today too
22:04 rue_house hmm
22:17 MrCurious dont' mess with Disney land in Russia... https://www.youtube.com/watch?v=sxanzw_RvTQ
22:20 rue_shop3 I bought some of the LM8UU bearings from china, honestly, I'm sure I'v used bushings that weren't much worse
22:37 applepi hi all :)
22:38 applepi question.. for a robot that needs to be tallish but maintain a small base, might a triangle base be better than a square for stability / not tipping?
22:39 orlock applepi: No
22:39 orlock applepi: http://en.wikipedia.org/wiki/Reliant_Robin
22:40 fluffywolf lol
22:42 Hyratel applepi, not really
22:43 Hyratel your chords of contact are farther from the center with a square
22:43 fluffywolf triangles allow easy tipping towards the sides... think of how close the midpoint on the side of a triangle is to the center of the triangle.
22:43 applepi Hyratel: true enough
22:44 orlock "Sudden direction changes and high-speed cornering attempts are not advisable"
22:44 applepi fluffywolf: yeah that's a thought
22:45 Hyratel is chord of contact the right term?
22:45 applepi i'm thinking it'll just need a bunch of dead weight in the bottom to keep it grounded i suppose.
22:46 fluffywolf looks like I'm going to have to use stronger measures to try to get my lathe centers... I haven't used the "find contact info" page on ebay in years. heh.
22:46 fluffywolf applepi: what does the robot do?
22:46 fluffywolf depending on the application, you can also do fancy balancing stuff. (think segway)
22:48 applepi fluffywolf: heh, maybe, though that's probably a little outside the realm of what we're shooting for..
22:48 applepi i'm mentoring a kid's ftc team, they're working on a robot that picks up wiffle balls and dumps them into a 3ish foot tall tube.
22:49 applepi they've come up with lots of good ideas but all require it getting the base getting crazy big to get tall and staying stable.
22:49 fluffywolf that sounds like you want a large, off-road base.
22:49 applepi i'm trying to come up with something to seed them with that they can run with that might save them from some tippage angst
22:50 fluffywolf the lift mechanism could be very light, and could fold/etc to lower cog during movement.
22:51 fluffywolf I can't imagine the lift mechanism weighing any substantial portion of the drive mechanism...
22:54 applepi fluffywolf: yeah, they've come up with a TON of good stuff, lots of belt feed stuff, but this is nxt/tetrix stuff and the base can be pretty light without some added stuff
22:54 fluffywolf a lightweight aluminum arm, two sections, maybe the lower one 1ft and the upper one 2ft, mounted to the front of the robot, then folded first back, then forwards, a pull cable/chain/etc to raise the upper section at the same time the lower one is raised, and either a pull cable to work a grabber, or a wire and small r/c servo...
22:54 RifRaf rue_house, hi there, work is ok, on night shift this week which is a bit :/
22:54 uffywolf has no idea what nxt or tetrix
22:55 fluffywolf arm sticks in front of the robot during movement, grabs ball, extends slightly so ball clears ground, moves with arm at this height, fully raises arm when at destination, drops ball
22:55 applepi fluffywolf: very lightweight stuffs. lift could reasonably move the center of gravity with tetrix motors and base.
22:56 applepi fluffywolf: they're mostly on conveyor style stuff since you can pull the goal around with you
22:57 fluffywolf ah. that's... odd.
22:57 fluffywolf how about a pneumatic tube system?
22:57 applepi ftc competitions are frequently odd. lol
22:57 uffywolf has no idea what a ftc competitio
22:57 applepi but fun.
22:57 fluffywolf well, I have some idea... it involves kids and whiffle balls. :P
22:59 applepi first tech challenge.. high school robotics.. usually some sort of "put X into Y, be able to find an IR beacon autonomously, plus a few misc things"... my coworkers and i are the team mentors
22:59 fluffywolf suck balls in the front, use a rotating section to move them to the other side of the blower, blow them into the receiver... nothing but lightweight tubing sticking up.
22:59 applepi it's good fun
23:00 applepi they've come up with something like that actually!
23:00 applepi alas our tetrix motors are damn puny and we doubt the ability to generate suction
23:01 techkid6_ fyc is weird
23:01 applepi they're going to get some fans and try it out
23:01 fluffywolf I take it there's size and weight limits?
23:01 techkid6_ im probably going to lead code this season
23:01 fluffywolf because I'd probably build this using wheelchair motors... :P
23:02 applepi only size limit is it has to start no bigger than 18x18x18", after that it can expand to however big
23:02 applepi motors are limited to tetrix motors though
23:02 applepi 1.6 ft-lbs, 155RPM :|
23:02 rue_shop3 can it use parts of the compeditors robot to expand?
23:02 fluffywolf lol
23:03 fluffywolf rue_house: I don't know if his motors have enough grunt to move the required chainsaw around.
23:03 rue_shop3 is it a li-ion chainsaw?
23:04 applepi XD
23:04 applepi everyone suggests a chainsaw
23:04 applepi the kids
23:04 applepi the parents
23:04 applepi everyone
23:04 fluffywolf lol
23:04 rue_shop3 then maybe you should find a way of incorperating a chainsaw
23:04 fluffywolf sad thing is chainsaws are utterly useless...
23:04 fluffywolf a spinning disc with one big tooth is sooooo much more effective...
23:04 rue_shop3 yes, but if you have one, everyone will just expect you to win
23:05 applepi they'll sure as hell get out of the way
23:05 rue_shop3 http://i.walmartimages.com/i/p/00/04/56/72/90/0004567290115_500X500.jpg
23:05 applepi wasn't the battlebot they eventually kicked off just a circular saw with a case?
23:05 rue_shop3 see, you just know he will be the winner
23:06 fluffywolf I really hate being restricted to crap components.
23:06 fluffywolf then it's not about making a good design, it's about working around the crap.
23:06 applepi they've actually opened it up this year, it was worse before
23:06 applepi there was a ton of "you can't use anything post processed" rules
23:06 rue_shop3 fluffywolf, was I gonna make you some cut-n-nut?
23:06 rue_shop3 I forgot who it was for
23:07 fluffywolf not I.
23:07 applepi aluminum channel: OK, aluminum channel with holes drilled already: BAD
23:07 rue_shop3 the instructions are on a peice of paper,
23:07 rue_shop3 lots of things are on peices of paper here in the shop
23:07 fluffywolf I could toss the channel on my cnc mill and make lots of holes... :P
23:08 applepi fluffywolf: yeah, that's the idea, you're allowed to do it yourself, but why force them to when you can just buy it ready to go..? the kids' teams with less money may not have a mill and stuff
23:08 applepi so I think that played a big part in them opening it up
23:09 applepi anyway, i'm off for the evening.
23:09 applepi good night all :)
23:09 fluffywolf cyas
23:10 rue_shop3 I have 1 hour to work on a project
23:11 rue_shop3 someone vote which project I hsould work on
23:11 rue_shop3 1) securrity door pass controller
23:11 rue_shop3 2) hexapod motor overloads
23:11 rue_shop3 3) trainer device for robot arm
23:11 rue_shop3 4) digital wall clock
23:11 rue_shop3 5) bench power supply
23:11 fluffywolf hexapod
23:11 rue_shop3 6) disc sander
23:12 rue_shop3 7) reprap
23:12 rue_shop3 hexapod?
23:12 rue_shop3 meh, ok
23:17 rue_shop3 ok
23:17 rue_shop3 1
23:17 rue_shop3 ok!
23:18 rue_shop3 so I had one knows flaw in my overload boards
23:18 rue_shop3 no filtering
23:18 rue_shop3 so the pwm pulses cause them to trip
23:19 rue_shop3 they were meant to be really fast, to protect the hardware, they are tooo fast
23:19 rue_shop3 where is that schamatic...
23:25 rue_shop3 the current sense resistor is 0.1R
23:26 rue_shop3 the amplifier input resistor is 800R
23:27 rue_shop3 the feedback resistor is 10K
23:27 rue_shop3 hmm
23:29 rue_shop3 that has to be a really big cap
23:29 rue_shop3 partly because there is only a voltage swing of .2V going into the whole mess
23:30 rue_shop3 but also cause its at a pretty low impedence
23:31 rue_shop3 .25mA
23:32 rue_shop3 so I want to limit .25ma to
23:32 rue_shop3 maybe I should put a power filter cap on the motor driver
23:34 rue_shop3 there is aparently NO filter cap on the driver section...
23:36 lfluffywof looking at the rules for applepi's competition, there's way too fucking many of them.
23:38 lfluffywof bbl, wolfy bedtime
23:49 rue_shop3 the largest nonpolar cap I have that I can fit in is 1uF
23:50 rue_shop3 so I have those in, if its not enough I'll add filter caps to the motor drivers
23:51 rue_shop3 wait a sec, adding a cap to the op-amp input will cause the output to swing harder
23:51 rue_shop3 bah, test bench
23:51 rue_shop3 tommorow