#robotics Logs

Aug 14 2015

00:39 JEntrep guys guys
00:39 JEntrep i need an answer
00:39 JEntrep this is important
00:40 JEntrep isn't there some sort of chemical agent that can be sprayed on an object to glide through water nearly frictionless?
00:40 JEntrep i could have sworn that there was something like this ...
00:41 JEntrep but I can't think of anything right now
00:41 JEntrep wouldn't a waterproofing chemical allow for this?
00:42 JEntrep rue_school, do you know anything?
00:42 JEntrep or am I just being stupid ??
00:43 rue_school what do I know about?
00:43 rue_school scotchguard?
00:43 JEntrep what is that?
00:43 rue_school not sure what it actually is
00:43 rue_school but it comes in a spray can
00:44 JEntrep I was hoping someone here could tell me whether or not a waterproofing agent on an object would allow it to travel through water with very little friction
00:46 rue_school no
00:46 rue_school air reduces friction
00:46 JEntrep ah ok
00:46 JEntrep thanks :)
00:46 rue_school and it can be applied in tiny bubbles
00:47 JEntrep isn't that what some waterproofing agents are doing?
00:47 JEntrep keeping a thin layer of air between water molecules and the object?
00:47 rue_school no, they just waterproof
00:48 rue_school they just seal
00:48 JEntrep what about this nano-coating stuff?
00:48 JEntrep http://www.liquipel.com/
00:49 rue_school no idea
00:49 JEntrep nm, I think they are advertising it as a "new surface" as well
00:49 JEntrep :/
00:50 JEntrep so if an object did maintain a thin layer of air between it and any water it came into contact with, it would say ... fall through the water like it was falling through air?
00:50 JEntrep I guess so?
00:51 JEntrep anyways ...
00:51 JEntrep thanks again :)
02:39 feelinblue hey hey, any humans still here?
02:41 deshipu no humans, no
02:41 deshipu just IRC nicks
02:42 feelinblue oh, has skynet finally taken over?
02:42 deshipu who is skynet?
02:43 feelinblue errr...
02:47 feelinblue anyways non-humans, could yall look over a schematic and tell me if im doing this thing right? its my first time doing building a robot with a pi
02:48 deshipu don't ask to ask, just ask
02:51 feelinblue so here's the schematic http://i.imgur.com/LjWIj2b.png and heres the parts im gonna use http://pastebin.com/uz32VrD4
02:51 feelinblue whois deshipu
03:02 deshipu um, that's not a schematic
03:02 feelinblue err then what is it?
03:03 deshipu I honestly have no idea
03:03 Jak_o_Shadows Block layout?
03:03 deshipu a schematic looks like this: http://www.labguysworld.com/CRV-59AAE_Schematic.jpg
03:04 feelinblue okay then, i guess i mislabeled
03:04 deshipu note how the pins are labeled with their functions, making it actually possible to see what is going on
03:05 deshipu what is that blue thing?
03:05 feelinblue uh its the power distribution board
03:05 feelinblue im planning on connecting a 7.5V usb hub for the pi to use to the variable output and the motor controller to the 12V output
03:06 deshipu did you draw it up-side-down?
03:07 feelinblue no ... what part of it seems upside down?
03:07 deshipu that big blue thing
03:08 deshipu I can't see a + wire for the rpi
03:08 deshipu you only connected the ground?
03:09 deshipu and you connected the ground to +5V?
03:11 feelinblue that's also a part im fuzzy on - i got that from here http://explainingcomputers.com/rasp_pi_robotics.html
03:12 deshipu and that's power *input*, not output
03:12 deshipu it's wrong
03:12 deshipu http://pi.gadgetoid.com/pinout <-- here's the pinout for rpi
03:13 deshipu you need to connect the grounds of all devices you are using together, and the apropriate power lines
03:13 deshipu how are you powering the rpi?
03:14 feelinblue either by slicing up a micro usb cable and powering that using the 5V variable output from the power dist board
03:15 deshipu no need for that, it's broken out on the header
03:15 feelinblue or is it possible to use the 5V and the ground from the motor controller to power the pi(by using pin 2 and pin 6)?
03:15 deshipu the 5V on the motor controller is input, not output
03:15 deshipu you need to provide 5V power there too
03:15 feelinblue oh damm
03:16 feelinblue i can't connect 12V and ground instead to the motor controller?
03:16 deshipu you need both 12V and 5V
03:17 deshipu the 12V is for the motors, the 5V for the electronics
03:17 feelinblue and the ground is negative im guessing?
03:17 deshipu yes
03:17 deshipu and all grounds should be connected together
03:18 deshipu you could adjust the UBEC to give 5V and power the rpi and the motor controller from that
03:19 feelinblue would running two power inputs from the 5V have any power hiccups?
03:19 deshipu no, the motor controller doesn't draw a lot of current
03:19 deshipu not on the 5V line, anyways
03:20 deshipu but it's a good practice to have separate pair of cables going from the ubec to each of the devices
03:21 feelinblue but i guess in this case that's not possible
03:27 deshipu something like this: http://paste.sheep.art.pl/b2703b59-f3f0-444b-ab2f-e70bb73f2370
03:27 deshipu just make sure it's exactly 5V before you connect the rpi
03:27 deshipu it's very sensitive
03:28 deshipu (note that the order of pins on my picture is all wrong, you have to go by the symbols)
03:28 feelinblue yah, i guess ill use a multimeter and test the voltage before plugging anything in
03:30 deshipu is that for a robot?
03:30 deshipu you probably want a motor with a gearbox, without it it will be way too fast
03:32 feelinblue yah it's for a robot, and i should probably do that
03:33 feelinblue is it too complicated to make your own gears? i have a ton of plastic gears from a VEX set sitting around
03:33 feelinblue edit: gearbox not gears
03:33 deshipu could work
03:34 deshipu a bit of mechanical design
03:34 feelinblue also, you said that all the grounds should be connected
03:34 deshipu by the way, speaking of rpi-based robots, I really love how this one came out: http://letsmakerobots.com/robot/project/pibot-a
03:35 feelinblue but one's 5V and the other is 12V so wouldn't that conflict?
03:35 deshipu no, all grounds are 0V
03:35 deshipu voltage is the difference between the 0V at the ground and the 5/12V
03:36 feelinblue ok
03:36 deshipu labeling them with a "-" is a little bit misleading
03:37 feelinblue so really it isn't positive and negative; its positive and GND?
03:38 deshipu well... you can think about it that way, in reality it's a little bit more complex
03:38 deshipu it theory you could as well connect all the +'s together, and have different -'s
03:39 deshipu but it's traditional to connect -'s
03:39 deshipu and that UBEC probably has all the -'s connected internally anyways
03:39 deshipu so stick to - being the ground
03:40 feelinblue ok, so ground could be anything but its "standard" to use negative as the ground - i think i get it now
03:40 deshipu voltage is the difference between charges
03:41 deshipu there is no + without a - to measure it against, you always need two wires
03:43 feelinblue so if i measured the charge from a battery and it's 15V, does that mean the (positive charge - negative charge) = 15V
03:44 deshipu yes
03:44 deshipu exactly
03:44 feelinblue ahhh, i feel enlightened
03:44 feelinblue thank you sensei
03:45 deshipu if you take two 1.5V batteries, and connect them in series, and measure from one battery's - to the other's +, you will get 3V, but if you measure from one battery's - to the center, you will get 1.5V
03:46 deshipu so it will be like that in this case with the UBEC and 12V and 5V
03:47 feelinblue so then would the 5V ( raspberry pi and motor controller ) need a different ground from the 12V motor controller
03:47 feelinblue because of the difference of charges
03:48 deshipu from the GND to 5V pins on the UBEC the charge is 5V, from the GND to 12V it is 12V
03:48 deshipu the GND is shared
03:50 feelinblue ahh got it
04:05 feelinblue ok, i redid the drawing, i think i fixed most of the probelms, could you give it a look over and see if it's alright? http://imgur.com/iU3uIB4
04:07 deshipu feelinblue: looks good, now, make sure you have separate cables going from the ubec to the rpi and from the ubec to motor controller
04:07 deshipu feelinblue: both for + and gnd
04:07 deshipu aah, you have the battery reversed!
04:08 feelinblue oh derp
04:08 feelinblue that might cause some problems
04:08 deshipu blue smoke, mostly
04:08 feelinblue do i get a genie afterwards?
04:09 deshipu depending on how much of the smoke you inhale, you may get all sorts of hallucinations
04:10 deshipu the thing is, the magic blue smoke powers that device, so when it is released, the device stops working
04:11 feelinblue but if you inhale it, you become turbocharged!!!
04:11 deshipu who knows
04:12 feelinblue i hope i never find out
04:12 deshipu try to not reverse or short-circuit things, not only you will burn them, but the battery may even explode
04:13 feelinblue uh oh, has that ever happened to you?
04:17 deshipu I broke some of my LiPOs, but fortunately they didn't explode, just became inflated
04:18 deshipu they are packaged to contain the gases
04:19 feelinblue how did you break them?
04:22 Kitae Q: Anyone here know where to look if I want to find compact or at the very least unconventionally shaped motors? Like, say, one that's flat and has a large diameter instead of having a small diameter and being not-particularly-flat as most of them seem to be.
04:23 deshipu Kitae: I would start with the usual chinese websites and ebay
04:23 Kitae Ditto for servoes, you'd think there're servoes with the arm protruding from the side (the side of what a regular servo would be like I mean) rather than the top
04:24 Kitae I think a relevant question to add is "any idea what search terms might help?" :D
04:25 deshipu http://www.aliexpress.com/w/wholesale-pancake-motor.html?site=glo&groupsort=1&SearchText=pancake+motor&SortType=price_asc&isUnitPrice=y&initiative_id=SB_20150814010149&shipCountry=CH
04:25 Kitae I've looked at banggood and several regional variations of ebay but couldn't even figure out what to actually search for
04:25 Kitae Oh, pancake motor?
04:25 deshipu yup
04:25 Kitae Hm, lots of tiny things primarily for generating vibrations there...
04:26 deshipu yeah, that's the most popular use for that shape
04:26 Kitae Ah. And huge car motors.
04:27 deshipu and bike
04:27 deshipu http://www.aliexpress.com/item/Electr-car-TDZ07Q-type-12-inch-front-wheel-14-inch-rear-wheel-models-the-oril-patent/32433637457.html
04:27 Kitae Oh yeah, there was a bike motor too.
04:28 Kitae I'm starting to get the impression my chances of finding what I'm looking for aren't very good
04:28 deshipu how about somethign like this? http://www.aliexpress.com/item/Free-Shipping-1pc-Intelligent-Car-Gear-Motor-TT-Motor-Robot-Gear-Motor-for-Arduino-New/2025246512.html
04:29 Kitae Is the yellow bit housing a gearbox or something?
04:30 deshipu yes
04:30 deshipu or this http://www.aliexpress.com/item/High-torque-Js-50t-DC-Iron-Gear-Motor-Home-Appliance-3v6v12v24v-Air-Conditioning-Electric-Fan-Microwave/1565096417.html
04:30 deshipu what do you need it for?
04:35 Kitae Nothing I've actually designed yet, but I have a few projects kicking around that're generally replicas of movie- or game-things. Like say, a nerf gun in the spirit of one of Mass Effect's fancy pistols. That causes space issues, I figured being able to fit motors in at other angles would help solve them a bit. Like you could lay a mostly-flat motor down on the side and not have the issue of
04:35 Kitae part of it protruding out the side of the pistol.
04:36 Kitae It hit me that something like this probably oughta exist and it might give me more design options. Something like that.
04:36 Kitae (Don't worry. I'm going to be building robots soon enough too :V)
04:37 Jak_o_Shadows Have you thought of worm gears
04:37 Jak_o_Shadows That may be your only optoin
04:37 Jak_o_Shadows and well, it'll give you the torque
04:37 Kitae Oh yeah, that could work.
04:38 deshipu so yeah, angle gears and worm gears to the rescue
04:38 deshipu Kitae: I think that yellow thing is actually a worm gear
04:39 deshipu http://www.aliexpress.com/item/DC-3-5V-80-130RPM-Output-Speed-Worm-Micro-Gear-Motors-30x12x8mm/32239894215.html <-- those are quite small and convenient
04:39 Kitae Now I feel dumb. Which I definitely should. But true, both of those are things that exist.
04:40 Kitae Oh neat
04:40 deshipu and those http://www.aliexpress.com/item/New-10pcs-DC-1V-5V-Worm-gear-micro-motor-DC-motor-10-150RPM-with-encoder-and/1922694195.html
04:40 deshipu the last one has an encoder, so you could probably make a servo :D
04:40 Kitae That looks like exactly what I was hoping to find :D
04:42 deshipu and for things that move in a line, there are those tiny stepper motors for camera lenses
04:42 deshipu with a screw and a slider
04:42 deshipu and they are really small
04:46 Kitae This definitely gives me plenty to work with. Thanks!
04:48 deshipu make sure to post anything you make here! :D
04:48 Kitae Sure, probably going to take a while.
04:48 Kitae But I will :>
04:48 Jak_o_Shadows aliexpress is great
04:48 Kitae I did already do SOMETHING at least.
04:48 Kitae though it's a nerf mod
04:49 deshipu pics or didn't happen
04:49 Jak_o_Shadows No shame if it's documented
04:49 deshipu by the way, those might be fun to mount on stuff: http://www.aliexpress.com/item/WLtoys-V959-V222-V262-V912-Accessories-Bag-Bubble-Blower-Water-Cannon-Missile-Launcher-Hook-Basket/32270679488.html
04:49 Kitae took one that uses motors to fire the dart but pushes the dart into it through... Uh, do you call it mechanics? Arm attached to trigger and dart-pushing stick, with an axis attached at the middle of the arm. Or something.
04:50 Kitae (English is not my primary language. Describing these things is harder than I thought it'd be <.<)
04:50 Kitae Either way I cut off the arm and fit in a servo instead.
04:50 deshipu yeah, all the rarely used words
04:50 Kitae I have videos actually :V
04:51 Kitae https://www.youtube.com/watch?v=BTwwMSab_gE
04:51 Kitae You can see the arm just... hanging there.
04:52 Kitae So it shouldn't be terribly hard to figure out what I meant I guess.
04:52 Jak_o_Shadows oooo, that is a nice mod.
04:52 deshipu nice
04:52 Kitae To the best of my knowledge nobody who posts things they do on the internet has fit a servo inside one of these like that
04:52 Kitae On the other hand most nerf modders like performance
04:52 Jak_o_Shadows Yeah, I've never seen it
04:52 Kitae and this one actually gets a lower fire-rate than you technically can achieve with manual fire.
04:52 Kitae Two darts per second, that's the cost for the tiny servo
04:53 deshipu you can make the servo faster
04:53 Kitae Until I gave it a (pretty terrible) paintjob it looked like a perfectly regular Stryfe once assembled though :D
04:53 deshipu by gluing two of its gears together and removing a third
04:53 Kitae ... I was going to say "not with stock batteries" but uh, really?
04:53 deshipu but it will be weaker
04:53 Kitae note: the force it needs to be able to push the dart with is part of the calculation
04:54 deshipu yeah
04:54 Kitae I measured an approximate required force, the length of the servo arm, the minimal distance it needs to push the dart to be sure it won't jam
04:54 deshipu another way is to increase the frequency of the PWM signal
04:55 deshipu of course it will heat then more
04:55 Kitae and then found the tiniest servo that it worked for at the voltage I'm feeding it
04:55 Kitae Eh, I'm perfectly fine with 2ps though
04:55 deshipu you could try SG92R instead of SG90 -- it's stronger
04:55 Kitae Oh?
04:55 deshipu and same size
04:55 Kitae Oooooooooooh?
04:55 Kitae That sounds really neat, I'll have a look at it
04:56 Kitae I could ofc also up the voltage
04:56 Kitae Though also, there's another bottleneck
04:57 Kitae darts don't always pop up immediately out of the mag
04:57 deshipu stronger spring :P
04:57 deshipu in the mag
04:57 Kitae Which is fun because that means while you could fire 4 darts by just pressing the trigger fast enough with a stock Stryfe... There's a real risk of jamming
04:58 Kitae I don't want to mod my mags though. I kinda like that you could just put any regular mag into it. But sure. I think some people actually do that.
04:58 Kitae I set up an IR-sensor and stopped there.
04:59 Kitae But ofc none of this is remotely as cool as building your own nerf gun from scratch so...
05:00 deshipu you know what could be fun?
05:00 Kitae (And ofc none of this is remotely as cool as building robots but I think that's a given.)
05:00 deshipu take the platic parts, scan them in, run them through a CNC and machine alluminium parts with the same shape and dimensions, then replace all springs and stuff with stronger versions
05:00 Kitae Hah.
05:01 deshipu that would cost a bit, but I bet there would be people willing to pay
05:01 Kitae That would be one hell of a cool makeover.
05:01 Kitae It'd probably be banned from every nerf war ever on account of no longer being plastic but sure.
05:02 deshipu hmm, ok, use carbon fiber instead
05:03 Kitae That sounds more expensive
05:03 Kitae Though I still don't know much about how one does things with carbon fiber
05:03 Kitae Do you work it similarily to how you work with glass fiber?
05:03 Jak_o_Shadows Yeah, except you generally don't use the chopped strand mat
05:04 Jak_o_Shadows Also, normally more directional
05:04 Kitae (I have cast molding projects running too, none of them deal with fibre though... Yet.)
05:04 Kitae So you use individual strands?
05:04 Kitae Even when making larger shapes?
05:05 Jak_o_Shadows Nah, you just uses matts pre-woven into shape
05:05 Kitae Oh.
05:05 Kitae Makes sense.
05:19 Kitae Oh yeah and as you said that second one has an encoder...
05:19 Kitae Though I could probably just use angle gears or something similar for servo-type things
05:22 deshipu I'm afraid that encoder is just for speed, not absolute position
05:22 deshipu so you need to know the starting position
05:23 Kitae That... Might be doable. Maybe.
05:23 deshipu or have an endstop switch for callibrating
05:23 Kitae Or I use angle/worm gear type things and SG92R/SG90 type things instead
05:23 deshipu or, if it's only supposed to move between 2 positions, just 2 endstops
05:24 Kitae Yeah, chances are that's what I'm going to end up having
05:24 Kitae Unless I do something like the rapidstrike's firing mechanism, where a switch in the stop-position shorts out the motor as long as you aren't holding down the gun's trigger
05:24 Kitae except mosfets and arduino etc
05:25 deshipu or an H bridge chip
05:25 deshipu I want to make the Killy's gun from Blame! one day
05:26 Kitae I've considered making a nerf version of Rettousei-protag Tatsuya's guns sometime.
05:27 Kitae If I can get this custom thing working then his guns happens to have dimensions that make it kinda easy to fit everything in
05:44 deshipu got a pic?
05:45 deshipu hmm, looks a little like Alucard's gun
05:46 deshipu http://cosplayers.acparadise.com/33989/33989-19057-1.jpg
06:41 deshipu_ urgh, the roomba just disconnected my server :/
06:44 Kitae deshipu_: That replica isn't terribly accurate though. The gun's body is actually -even taller-.
06:46 Kitae http://cooterie.com/img/works/52289b29f3001f68f02de88c46b66cb1a9690c3d.jpg
06:46 Kitae incidentally with the outrunners I have I could fit the flywheel mechanism in a ~50mm tall space
06:47 Kitae so... the only problem is the width of thep istol which'd have to be greater than in the original design
06:49 deshipu_ somehow I really don't like that design
06:49 deshipu_ it looks like drawn by someone who never saw a pistol
06:49 deshipu_ the handle is all wrong, it's too high
06:52 Kitae Canonically it isn't actually a pistol
06:53 Kitae It's a magic wand pretty much.
06:53 Kitae (Rettousei is weird.)
06:53 veverak lol
06:53 Kitae But it's also a popular series with a decent degree of recognition :V
06:53 verak knows th
06:53 Kitae So making nerf out of iti s fun
06:53 veverak deshipu_: yeah, it's not ment to be normal gun
06:54 veverak but alucards are much cooler
06:54 veverak :)
06:54 deshipu_ cosplaying popular stuff is boring
06:55 veverak yeah, I see your point
06:55 veverak :0
06:55 veverak god damn it my google-fu sucks
06:55 verak can't find somethign that would tell
06:55 veverak which countersunk tool I want
06:55 veverak I mean
06:55 veverak with how many edges
06:55 Kitae I don't do cosplay :V
06:56 deshipu why not?
06:56 Kitae Not actually interested
06:56 Kitae Props are really, really cool
06:56 Kitae But I'm more into things that can actually be used
06:56 deshipu well, making props is what it is all about, no?
06:57 deshipu and even better if you can use them
06:57 Kitae I wouldn't make a cosplay sword, but I wouldn't mind making an actually functional boffer sword that also serves as an anime prop
06:57 Kitae Not interested in sewing outfits etc.
06:58 Kitae On that note
06:58 Kitae https://c1.staticflickr.com/9/8438/7775380144_9ef01b48ee_b.jpg this thing
06:58 deshipu make a chainsword \o/
06:58 Kitae but also firing nerf darts
06:58 Kitae is what I'm going for
06:58 deshipu looks a little like seburos
06:58 Kitae Probably going to go for a tiny custom-made 4- or 5-dart mag
06:59 Kitae haven't quite decided how or where
06:59 deshipu have you considered BB-guns?
06:59 Kitae Ofc it would be REALLY neat to have a p90-style mag fitted up top above the trigger
06:59 Kitae Eh, you can shoot people with nerf darts
06:59 deshipu there is a huge community of people making accurate models of them
06:59 Kitae and only cause minor annoyance at most
07:00 deshipu what do you think about those gel balls?
07:00 deshipu the ones you soak in water
07:00 deshipu http://www.aliexpress.com/item/10000pcs-lot-Paintball-Gun-Pistol-toy-gun-bomb-party-toys-shooting-Water-Gun-Crystal-ball-bullet/32274708706.html
07:00 Kitae And if I ever were to join a larp then nerf is larp-friendly (I have a friend who joins in the occasional sci-fi larps and is working on getting a firefly larp off the ground soonish etc)
07:03 Kitae I basically just like the flywheels though. It's a nifty concept.
07:04 Kitae and gets you like-a-bullet-but-longer-shaped things
07:12 deshipu hmm, so you built them to be functional, but don't really use them?
07:13 Kitae Well, I haven't built any custom gun yet
07:13 Kitae But sure, the one I modded there for example is hella cool
07:13 Kitae but I have yet to use it in any kind of actual nerf fight
07:13 Kitae And I don't imagine it's going to happen any soon, because that wasn't ever the point.
07:13 deshipu that's like me painting minis
07:14 Kitae I mean it's cool if you could but I'm not into nerf for the nerf wars
07:14 Kitae I'm into nerf because HEY LOOK THEY'RE GUNS I'M ACTUALLY ALLOWED TO SHOOT YOU WITH
07:14 Kitae I did mention the ir-sensor btw, right?
07:14 Kitae Because that ir-sensor setup is like... Basically everyone ever should want a mod for their stryfe that adds that
07:14 Kitae and prevents firing unless there's a dart ready
07:15 deshipu how about laser tag?
07:15 deshipu that's safe too, no?
07:15 deshipu and you could make much cooler guns, as you only need a LED
07:16 deshipu that fits into almost anything
07:16 Kitae The wait time is -usually- just like <= 50ms (can be a full second or two sometimes, the mags are very silly unreliable) but it has brought down the jamming rate to... almost 0%
07:16 Kitae I can't remember the last time it jammed
07:16 Kitae Eh
07:17 Kitae There're two things that aren't fun about that
07:17 Kitae 1. no cool firing mechanisms
07:17 Kitae 2. need vests to register hits
07:17 deshipu and with nerf you don't even ever register them
07:17 Kitae The act of retrieving a dart out of a magazine and then firing it is cool
07:17 Kitae You see it hit :D
07:18 Kitae but more importantly you see it fly, which is neat and cool and stuff
07:18 deshipu you could make the gun tell you when it hit someone
07:18 deshipu without a vest
07:18 Kitae That is cool and fancy, sure
07:18 deshipu heck, you could put a camera in it and make it snap a photo showing exactly where it hit
07:18 Kitae Cooler and fancier would be to have the gun tell you "you aren't aiming at anything so I'm not going to shoot herp derp"
07:18 deshipu overlay a crosschair on the photo
07:19 deshipu well, speaking of that, autoturret
07:19 Kitae Never cared much for them. Though I guess if the turrent in question is a fully functioning (minus the part where it kills people) portal turret then I can see the appeal
07:20 Kitae turret*
07:20 Kitae facial recognition is a must, obviously
07:20 Kitae just so it can decide if it should say "hello" or "hello again"
07:22 Kitae You know, the important things
07:29 deshipu sure
09:29 Sublime Any one in here familiar with server motors and their drivers?
09:30 deshipu server or servo?
09:32 deshipu also, ask your real question
09:36 Sublime sorry servo. I need more torque than a stepper can provide. I hear that servo motors are able to provide huge amounts of torque but im not able to find much information about them online
09:38 deshipu well, there are all sorts of servo motors and stepper motors, and I don't think any one type inherently provides more torque
09:38 deshipu also, servos with high torque are very expensive
09:39 deshipu what are you trying to do?
09:39 Sublime I'm talking more industrial type servo motors like the ones on CNC machines not for an R/C Car
09:39 Sublime Im tasked on an R&D project to replace some hydrological cylinders with electronic motors
09:40 deshipu you mean hydraulic?
09:40 Sublime yeah sorry. auto correct is killing me today haha
09:41 deshipu what torque do you actually need?
09:41 Sublime for one of our small applications around 10ft lb for larger ones 50+
09:41 Sublime also needs to be fairly quick
09:42 Sublime Also why i was thinking a servo because they can spin faster than a stepper an I could use some gearing to archive those torque levels.
09:43 deshipu 140kg*cm
09:43 deshipu whew
09:43 Sublime Yeah. its actually for injection molding. needs to be able to unscrew from the part.
09:43 Sublime Depending on the size and pitch of the threading in the part it can need a lot of force to break free
09:46 Sublime deshipu, I was thinking something like this: https://www.teknic.com/model-info/CPM-SDSK-2311S-EQN/
09:47 deshipu well, I only have some experience with the small hobby servos used in model aeroplanes, and some theoretical knowledge about the more advanced small robotics servos like dynamixels. no idea about the actual large industrial stuff
09:49 Sublime yeah I'm in that same boat. industrial stuff has far more wires coming off of the motor and use very high voltages. We have a machine here that runs off of 600v drives
09:52 veverak FUCK
09:55 Sublime yeah i really dont like working on it
10:08 deshipu veverak: temper
10:12 verak have to release the s
10:12 veverak and better with words than with hammer
10:15 deshipu well, I personally would prefer a hammer, becuase it wouldn't reach me, as opposed to the words
10:15 veverak well
10:16 veverak on the other hand, if by any chance you would be in same room and that hamnmer slipped from my hand it would...
10:16 veverak of course not intentionally, it's just what you hit something with hammer full of rage things can happen
10:24 veverak but
10:24 veverak I suppose I am finally getting clue why my Y axis is so shitty
14:07 JEntrep has anyone here ever built a railgun? :)
14:23 deshipu I had a (failed) attempt at a coil gun once
14:23 deshipu rail gun requires too high voltage
14:26 Hyratel rail gun uses very high power. higher than coil guns
14:26 Hyratel its efficiency is very poor for low power levels
14:27 sherlock sure but it only needs to be powered for a very short period
17:19 JEntrep I read that the rails on a railgun become unsuable after a few full-powered shots
17:19 JEntrep does anyone know more about why this happens?
17:27 deshipu JEntrep: sure, they get eaten by the plasma
17:27 JEntrep plasma? :o
17:27 deshipu JEntrep: yup, the air in front of the missile heats up and turns to plasma
17:27 deshipu it's several mach speed, after all
17:28 deshipu with a huge acceleration
17:28 JEntrep :/
17:28 deshipu not something you want to do at home
17:28 JEntrep everything has a down side
17:29 JEntrep what if you shot a railgun in vacuum?
17:29 deshipu weapons seem to generally only have down sides
17:29 JEntrep no detoriation of rails?
17:29 JEntrep *deterioration
17:29 SpeedEvil Railguns use metal ion contactors.
17:29 SpeedEvil the rails always degrade
17:29 deshipu no idea, you may lose material due to the electrons leaving in vacuum
17:29 deshipu you know, like in a vacuum tube
17:30 JEntrep :/
17:30 JEntrep what is a metal ion contact?
17:30 JEntrep links?
17:31 SpeedEvil Plasma
17:32 JEntrep you meant the rails come into contact with plasma?
17:32 JEntrep because deshipu was saying that was because of the air
17:32 JEntrep I was wondering about a railgun in a vacuum
17:33 JEntrep would there still be plasma produced?
17:33 deshipu there are several sources of the plasma
17:35 JEntrep what else?
17:35 deshipu high power electricity
17:35 deshipu melting and vaporizing of the missile itself
17:36 deshipu friction with the missile
17:36 deshipu generally I wouldn't want to bee within sight of a shooting railgun
17:37 deshipu especially one made in a garage
17:39 SpeedEvil It is plasma generated by the high current flow between track and rail
17:40 JEntrep hmm
17:40 JEntrep interesting
17:40 deshipu SpeedEvil: I didn't know there is any current flowing there
17:40 deshipu SpeedEvil: I thought it's based only on the electric charge
17:41 SpeedEvil Railguns are powered entirely by magnetism, not charge
17:41 deshipu SpeedEvil: that's coilguns
17:41 SpeedEvil there is truly massive current flowing through the projectile - hundreds of thousands of amps
17:41 SpeedEvil Nope.
17:41 SpeedEvil Railguns are powered by the expanding magnetic field reacting against the current flowing through the projectile
17:41 JEntrep the object in the middle completes the circuit right?
17:41 SpeedEvil yes
17:42 deshipu railguns work by the principle that same charges are pushed away -- the charged projectile is pushed out from between the charged rails?
17:42 SpeedEvil the current flows up one rail, through the plasma, through the projectile/pusher/...
17:42 SpeedEvil deshipu: nope, not at all
17:42 deshipu SpeedEvil: then how do you call those?
17:42 SpeedEvil deshipu: you don't, as they're not a thing, other than for subatomic particles.
17:43 deshipu :/
17:43 SpeedEvil particle accellerator
17:43 SpeedEvil for macroparticles, the charge/mass is terrible
17:43 deshipu I've been living in error
17:45 JEntrep A railgun requires a pulsed, direct current power supply
17:45 JEntrep from wiki
17:46 SpeedEvil The pulse is as long as the firing
17:46 SpeedEvil it's not pulsed in the sense of controlled
17:46 JEntrep can anyone get me some papers of IEEE
17:46 JEntrep ?
17:46 JEntrep *off
17:48 JEntrep nm
17:48 JEntrep found some other good papers
17:50 JEntrep thanks SpeedEvil
17:54 JEntrep so if I wanted to go back to school to do research on railgun design
17:54 JEntrep what degree field would that be?
17:54 JEntrep electrical engineering?
17:54 JEntrep mechanical engineering?
17:56 ace4016 electrical primarily
17:56 JEntrep i wonder which school has a research department working in that area
17:56 ace4016 mechanical if you want to solve the problem of finding materials that survive the forces experienced as its rails fall apart
17:57 ace4016 the railgun concept is fairly simple though...
17:57 JEntrep yeah the materials science of it might be most important at this point in time
17:58 JEntrep SpeedEvil, any thoughts?
17:58 ace4016 at the level of research, both fields study materials
17:58 SpeedEvil I want to use a railgun on several people, otherwise - not
17:58 SpeedEvil More seriously - railguns are engineering
17:59 ace4016 and tbh, in the real world, you're likely to see a mixing of the two anyways
17:59 SpeedEvil Probably EE/ME/physics
17:59 ace4016 an ME doing electrical stuff and EE doing mechanical stuff
17:59 JEntrep yeah pure physics would work too I guess
17:59 ace4016 they use the same math and such
17:59 SpeedEvil i mean all three
17:59 JEntrep I guess the best school for material science is MIT?
17:59 ace4016 heh, pure physics wouldn't work...
17:59 JEntrep SpeedEvil, well it all boils down to physical principles in the end
18:00 ace4016 JEntrep, for undergrad or masters/phd?
18:00 JEntrep er ... applied physics
18:00 JEntrep graduate
18:00 ace4016 MIT isn't the only one around
18:00 JEntrep sure
18:00 JEntrep I just wouldn't waste my time
18:00 ace4016 look at where the research is coming from, outside of like...the government funded labs
18:01 JEntrep in all honesty, I could care less about the school
18:01 ace4016 if that's the case, why not just get some books and study specifically what you want?
18:01 JEntrep so I guess I will just have to look for a paper or something I like and see which research group it came out of
18:01 JEntrep I will do that as well
18:01 JEntrep This would also be a networking move for me if I decided to pursue it
18:01 ace4016 not everything is taught in school :P
18:02 JEntrep also access to expensive equipment would be nice ;)
18:02 ace4016 and you won't get much out of graduate school unless you do something in the labs
18:02 JEntrep trust me, I would care less about the school
18:02 ace4016 why not just work at a research lab then :P
18:02 JEntrep *I will care less and less about the school everyday
18:02 JEntrep ace4016, are there any that focus on this?
18:03 ace4016 on railguns?
18:03 ace4016 yea
18:03 JEntrep like who?
18:03 JEntrep DoD?
18:03 JEntrep :p
18:03 ace4016 dahlgren (navy)
18:03 ace4016 and a few others
18:03 JEntrep well I know the Navy does stuff
18:04 JEntrep but I would rather not have to deal with government bs
18:04 ace4016 if you're looking to do railguns, you're looking at government stuff :P
18:04 JEntrep :(
18:04 chris_99 i guess you've seen the BAE one https://www.youtube.com/watch?v=-uV1SbEuzFU
18:05 JEntrep chris_99, yep :)
18:05 ace4016 they're weapons for the most part. you can use them to launch space vehicles, but that's NASA, another government agency (which isn't far removed from DoD)
18:05 JEntrep that thing can only fire a max of 400 times though
18:05 JEntrep before rail replacement
18:05 ace4016 and you can be damn sure the USAF and Navy/SPAWAR want easy launches into space and such :P
18:06 JEntrep ace4016, for what?
18:06 JEntrep nm
18:06 ace4016 both agencies have space warfare projects
18:06 JEntrep that could be a very long list of things
18:06 JEntrep jfc the military industrial complex pisses me off
18:07 JEntrep I can't tell what pisses me off more, that or crony capitalists.
18:07 ace4016 but you want to research and go to school for an item that is primarily a weapon
18:07 ace4016 what did you expect? :P
18:08 JEntrep because the technology is not weapon-specific
18:08 ace4016 it's not; but it's applications aren't exactly the widest
18:09 JEntrep yet ...
18:09 ace4016 just about all railguns i've seen have been backed by DoD money
18:10 JEntrep yeah, probs
18:11 ace4016 also, the sad truth is that businesses don't like spending money on research when possible. it's usually high risk and a large expenditure
18:11 ace4016 when you've got profit margins and such to worry about, it's done when needed
18:11 ace4016 government has no concept of profits per se
18:13 JEntrep but the peewee brains in government think that the only incentive a government has is to increase its military
18:13 JEntrep that is like the "shareholders value" of politcians
18:13 JEntrep "profit"
18:14 JEntrep it is silly and shows extreme ignorance and incompetence
18:14 JEntrep something that was steadily avoided by politicians pre-WWII and especially pre-WWI
18:14 ntrep s
18:15 ace4016 heh, the DoD isn't the only one that makes expenditures in research
18:16 ace4016 DoE, DoT, NASA, NSF, etc. all put out research money as well
18:16 JEntrep sure
18:16 JEntrep but it's all as minimal as it can be
18:16 ace4016 just...if your interest lay in weapons, expect the DoD to be funding you :P
18:16 JEntrep my interest is not in weapons
18:17 JEntrep it's in electromagnetic acceleration devices D:
18:17 JEntrep just because you accelerate a bullet with that has nothing to do with me ...
18:18 ace4016 that are good for really short distances (a few meter barrel), and destroy themselves due to the forces on teh rail
18:18 ace4016 yes
18:18 ace4016 you may want to look into MAGLEV trains if you want electromagnetic acceleration devices or something :P
18:19 ace4016 or motor research
18:19 SpeedEvil maglev trains and weapons have almost nothing to do with each other
18:19 ace4016 there's a resurrgence in switched reluctance and reluctance synchronous motors :P
18:19 SpeedEvil the energies are so enormously different
18:19 ace4016 see? maglev seems great then! no military industrial complex
18:22 ace4016 there's also medical tools and factory conveyor systems that could better be designed
18:22 ace4016 boat propulsion i'm sure needs more work
18:22 ace4016 and there's physics research that uses electromagnetics to accelerate all sorts of things together
18:22 JEntrep yeah lol
18:23 JEntrep well I have to go read stuff
18:23 JEntrep so cya guys later tonight or tomorrow or whenever
18:23 JEntrep thanks again :)
18:24 ace4016 o/
18:36 anon6451 is there any other way to achieve flying agility of quadrocopter by some other configurations?
18:37 anon6451 like a bicopter?
18:38 anon6451 I guess odd-numbered copter will rotate because blades can't be balanced out, right?
18:38 ace4016 not necessarily
18:38 ace4016 you can compensate whenever necessary in your design
18:39 anon6451 okay, so tricopter is possible. what about bicopter?
18:51 SpeedEvil anon6451: chinook
18:52 anon6451 and convertoplanes, I know that they exist
18:52 anon6451 I mean can they work with a simple , non mechanised blade
18:53 SpeedEvil Two rotor craft are not simply controllable if you just have the two motors
18:53 SpeedEvil At best, marginal
18:59 ace4016 hrm...if you seperate the rotors far enough from each other so they can never touch, you can yaw and pitch in a chinook/sea knight configuration; you can roll and yaw in a uh...Osprey configuration
18:59 ace4016 assuming non-mechanised blades
19:00 ace4016 without some really funky manuevers
19:00 SpeedEvil anon6451: chinooks have swashplates
19:00 ace4016 yea
19:00 SpeedEvil without swashplates - with only rotor RPM - in order to gain control in the other axis, you first have to slew
19:01 SpeedEvil which means speeding up one rotor and slowing down the other, which incidentally causes a massive prompt pitch
19:01 SpeedEvil I'm not saying it's not controllable by computer, in some circumstances, but...
19:01 anon6451 VTOL and horizontal movement with turn I. that direction - is it possible in osprey configuration? (I really like osprey, BTW!)
19:01 ace4016 you do?
19:02 ace4016 also, that sentence broke down for me in the middle
19:03 ace4016 V-22 also uses swashplates for the same reason the chinook and seaknight do
19:04 anon6451 with a turn in that direction*. that was auto replace, sorry.
19:05 ace4016 for the simplest control design, three variable speed rotors would probably be ideal for you
19:05 ace4016 if you're not doing a swashplate design
19:05 anon6451 swashplate is a nightmare
19:08 anon6451 if we will use two rotors that will constantly be tilting as in osprey, to maintain balance - will it work? or turning a rotating blade is not a good idea?
19:09 anon6451 without statically balance (so as soon as electronics fail ,it will roll over, I guess)
19:09 ace4016 it caused bell-boeing a lot of issues :P
19:09 ace4016 but the osprey also has a swashplate
19:10 anon6451 is there any example of osprey configuration without swashplate?
19:12 SpeedEvil http://nari.arc.nasa.gov/learnseminar2013 - watch the Full-scale Experimental Validation of Dynamic, Centrifugally Powered, Pneumatic Actuators for Active Rotor Blade Surfaces
19:13 SpeedEvil video
19:13 SpeedEvil https://www.youtube.com/watch?v=aEPf0QHVuMM also
19:15 ace4016 heh, interesting technic
19:15 ace4016 it's still a mechanized blade though
19:16 ace4016 just lacking a swashplate
19:20 anon6451 last one is amazing!
19:21 SpeedEvil trading hideous complexity in the swashplate for two bearings which might in principle be doable by designing the prop to flex just right
19:22 anon6451 I thought about flexable blade too
19:24 anon6451 the only thing that I don't like in that design is a lower blade. too vulnerable at landing/take off
19:25 ace4016 could probably displace that to a higher setup
19:34 SpeedEvil anon6451: a standard coaxial setup would work just fine
19:35 anon6451 one above another? that will require a hollow shaft, right?
19:37 ace4016 concentric shafts
19:37 ace4016 one will likely be hollow :P
19:39 anon6451 likely? come on, we are still in a three dimensional space, you know..
19:40 anon6451 hollow shaft is a problem too, I guess
19:40 ace4016 tubes are cheap
19:41 ace4016 guess you'll probably need a bearing of some sort though
19:41 ace4016 you could also have o-|--| type of configuration
19:42 anon6451 you need a whole motor shaft to be hollow
19:42 SpeedEvil you can buy motors to do this
19:42 anon6451 so second motor with a really long shaft will go through
19:42 anon6451 and both have to be unbendable and with some sort of lubrication
19:43 SpeedEvil Or you just buy it
19:44 SpeedEvil http://hobbyking.com/hobbyking/store/__10591__CR23M_Contra_Rotating_BL_System1550kv.html
19:44 anon6451 it should be more expensive, I guess
19:46 anon6451 50$ instead of 5$ for a non-hollow motor
19:47 SpeedEvil yes
19:47 SpeedEvil there is that
19:47 SpeedEvil perhaps not actually 5
19:48 ace4016 could build two motors butt to butt with rotors at their ends; one rotor happens to also be connected to the body below the motor/rotors
19:48 anon6451 China with kids working at night shifts can do it for 5 :)
19:49 anon6451 why not seaknight or v-22 configuration? cheap motor can be used then
19:50 ace4016 i guess so, if you're using the above techniques
19:59 anon6451 http://youtu.be/AD9juUWL5iU one blade helicopter toy , no tail rotor and one blade on. a main rotor (no vtol , but can hover at few m/s, the idea is interesting)
21:56 codepython777 Why are dc motors with higher rpm (340) cheaper than lower rpm (122)- in the same type?
21:57 Hyratel1 codepython777, explain?
21:57 Hyratel1 do you mean gear motors?
22:09 codepython777 Hyratel1: gear motors
22:09 codepython777 Hyratel1: http://www.superdroidrobots.com/shop/item.aspx/ig42-24vdc-122-rpm-gear-motor-with-encoder/849/
22:12 Hyratel1 higher ratio gears, or just more of them
22:13 codepython777 I think i know why the lower rpms are more expensive
22:13 codepython777 Hyratel1: how do i get a motor mount for that motor? Are there generic motor mounts that will help me attach that motor to a alum shaft? or my chasis?
22:16 Hyratel1 http://www.superdroidrobots.com/shop/item.aspx/single-motor-mount-ig32-or-ig42-sb/1051/
22:17 codepython777 Hyratel1: $42 for a piece of metal ? Can't buy that one
22:17 Hyratel1 then look up IG42 mounts
22:19 codepython777 google cant find anything
22:20 Hyratel1 guess you're SOL then
22:20 codepython777 i guess the motor is cheap for a reason :)
22:20 Hyratel1 do you have your own machining/tooling ability?
22:21 codepython777 just a 3d printer
22:21 codepython777 no cnc
22:21 codepython777 Hyratel1: do you have any?
22:21 codepython777 so robot work - i do need to get one?
22:21 codepython777 no hope without that?
22:21 Hyratel1 I have a power drill and a drillbit set
22:22 codepython777 that wont work for this problem , right?
22:22 Hyratel1 if you have a straightedge, a layout pin (heavy, longpointed needle), and a good ruler, you can do it
22:22 Hyratel1 and a square
22:23 Hyratel1 add a set of decent small files
22:24 codepython777 Hyratel1: i want to build a couple of these
22:24 codepython777 either i've to find cheap mounts - or - spend a lot of time - or get a cnc - that sounds not so good
22:25 Hyratel1 ¯\_(ツ)_/¯
22:26 Hyratel1 you'll have gotten used to doing layout
22:26 Hyratel1 by the third
22:26 codepython777 Hyratel1: you made some bots recently, right? I remember seeing something from you
22:27 Hyratel1 that was all basic framing
22:27 Hyratel1 my brother did most of the fab, too
22:27 Hyratel1 https://dl.dropboxusercontent.com/u/33593534/images/Robot/DSCN2011-1k2.jpg
22:27 codepython777 which motors did you use?
22:28 Hyratel1 those?
22:28 Hyratel1 those are 1/2 HP CIM motors, available from Andymark, and using CIMple boxes
22:28 Hyratel1 signle stage gearboxes
22:28 codepython777 encoders?
22:29 Hyratel1 nope
22:29 Hyratel1 it's "just" R/C
22:29 Hyratel1 differential skidsteer
22:30 codepython777 how much were the motors?
22:31 codepython777 did you buy the frame from andrymark as well?
22:32 Hyratel1 frame is scratchbuilt. 1" Square box tube, pre-perf at 1" centers
22:35 codepython777 Hyratel1: do you have a link to the motor you bought? did it come with any kind of warranty?
22:36 Hyratel1 sec
22:37 codepython777 do you have a parts list somewhere?
22:38 Hyratel1 https://www.sparkfun.com/news/1450
22:40 codepython777 motor controller link is broken
22:40 Hyratel1 discontinued model
22:41 codepython777 how many motors?
22:41 codepython777 2?
22:41 Hyratel1 yep. one per box
22:41 codepython777 is there a reason to get 4 motors? more power?
22:41 Hyratel1 yes
22:42 Hyratel1 you set up paired motors and controllers with a PWM-Y cable
22:42 codepython777 what is more power efficient - for the same payload capacity? 2 motors or 4?
22:42 Hyratel1 eh?
22:42 Hyratel1 you get twice the torque, at twice the drain
22:43 codepython777 Hyratel1: I'm new to this - hence the questions :)
22:44 Hyratel1 codepython777, the gearboxes have two motor mount brackets, with A/B/AB as easy option
22:48 codepython777 Hyratel1: http://www.orionrobotics.com/RoboClaw-2x30A-Motor-Controller-with-USB_p_331.html - was thinking of using these motor controllers
22:48 codepython777 these motors: http://www.superdroidrobots.com/shop/item.aspx/ig42-24vdc-122-rpm-gear-motor-with-encoder/849/
22:48 codepython777 for a smaller robot
22:49 Hyratel1 what do you need 30A for?
22:49 codepython777 Hyratel1: where are you located? FLhere
22:49 codepython777 Hyratel1: stall current
22:49 Hyratel1 VA here
22:49 Hyratel1 wrong number
22:50 codepython777 k?
22:50 codepython777 what should i get?
22:50 codepython777 for those motors
22:51 Hyratel1 http://www.usfirst.org/uploadedFiles/Robotics_Programs/FRC/Game_and_Season__Info/2011_Assets/Kit_of_Parts/Motor_Curves_Rev_A.pdf
22:52 Hyratel1 last pag
22:52 Hyratel1 page
22:52 codepython777 so max power used is 350A?
22:53 codepython777 also, how did you attach the motor shaft to the wheel?
22:53 Hyratel1 Power is the energy delivered through the shaft
22:53 Hyratel1 you don't
22:54 Hyratel1 at least not with big shit
22:54 Hyratel1 you use a reduction gear
22:54 Hyratel1 https://dl.dropboxusercontent.com/u/33593534/images/Robot/DSCN2016-1k2.jpg
22:55 codepython777 how did you make the plates with holes to attach the wheels?
22:55 codepython777 also the shaft can slide laterally in your design, right?
22:56 Hyratel1 we... didn't
22:56 Hyratel1 we bought sprockets
22:57 codepython777 Hyratel1: https://www.servocity.com/html/aluminum_hub_mount_sprockets__.html#.Vc6zKvm6ftQ - something like this?
22:57 Hyratel1 yes
22:57 codepython777 i see, so you have use a chain to transfer power
22:57 Hyratel1 though the ones we got were 4-hole pattern and matched the bolt pattern on the wheels we got from harbor freight
22:58 codepython777 i want to attach the motor directly to the wheel - how do i do that?
22:58 Hyratel1 motor?
22:58 Hyratel1 or gearbox shaft
22:58 codepython777 shaft
22:58 codepython777 i want to transfer motion of the shaft to the wheel
22:58 Hyratel1 well, first you check the size and shape of the shaft
22:58 codepython777 k
22:58 Hyratel1 see if it has a Flatted, Keyed or Hex shaft
22:59 codepython777 Hyratel1: http://www.superdroidrobots.com/images/IG42-Gear-Motor.jpg
22:59 Hyratel1 that's a flatted shaft
23:00 codepython777 i was guessing that
23:00 codepython777 k - now how do go about putting a wheel on it
23:00 Hyratel1 you use a molded plastic friction-fit wheel, or a metal gear/wheel with a set screw
23:01 Hyratel1 something I've seen on desk fans with a flatted shaft is the sleeve has a slot going across it, with a spring wrapped aorund it
23:01 Hyratel1 this gives a more reliable, tighter friction fit than relying on the spring tensility of the plastic along
23:01 Hyratel1 alone
23:03 codepython777 I think these will fit as is: http://www.superdroidrobots.com/shop/item.aspx/atr-wheel-and-shaft-set-pair-8mm-bore-10-inch-traction-lug/1995/
23:03 codepython777 only problem is price
23:03 codepython777 how much were your tires?
23:04 Hyratel1 $7/ea
23:04 codepython777 and these are $50/each - smaller worse than yours for sure.
23:05 Hyratel1 http://www.harborfreight.com/material-handling/pneumatic-tires/10-inch-pneumatic-tire-30900.html
23:05 codepython777 wow
23:05 codepython777 how much load can it take?
23:06 Hyratel1 well the rolling friction goes way up with more than ~ 100Lb/4 tires
23:06 Hyratel1 which is fine for a handcart, not so great for a self propel
23:06 codepython777 wish they had 8" tires.
23:07 Hyratel1 Hormes weighs 60+ lb
23:07 codepython777 even then attaching it to a shaft would be a problem for me. All i need is 4 screwed circular shaft that attaches to the flat key shaft on the motor.
23:07 Hyratel1 http://www.harborfreight.com/8-inch-non-marring-rubber-tire-47638.html
23:08 Hyratel1 http://www.harborfreight.com/8-in-solid-rubber-tire-with-steel-hub-61706.html
23:08 codepython777 Hyratel1: last one is nice - how do i use it on a motor shaft?
23:09 Hyratel1 knock out the bearings, find someone who can make press fit mounts for a live axle
23:09 Hyratel1 vocab words
23:09 Hyratel1 live axle / dead axle
23:10 codepython777 why dont they sell a part that attaches to a motor shaft at one end, and the wheel on the other! ?
23:10 Hyratel1 vocab words
23:10 Hyratel1 live axle / dead axle
23:10 Hyratel1 dead axle is like Hormes
23:11 Hyratel1 solid metal shaft bolted to the frame
23:11 Hyratel1 wheels have bearings and power is provided by a gear, belt, or chain drive
23:12 Hyratel1 live axle has the bearings mounted to the frame, sometimes as part of the motor or gearbox body
23:12 Hyratel1 wheels have no bearings and are mounted solidly to the rotating axle
23:15 codepython777 Hyratel1: https://awwapp.com/b/uzuykgw1b/
23:18 codepython777 Hyratel1: so just using an adapter would generate too much heat?
23:19 codepython777 one could hex slot the wheel on the shaft, isnt it?
23:31 Hyratel1 codepython777, eh?
23:31 Hyratel1 I do not understand this picture
23:34 choonway haa haa
23:36 choonway you need something like this perhaps? https://www.pololu.com/product/1079
23:36 JEntrep I am back
23:37 Hyratel1 codepython777, ^
23:39 Hyratel1 codepython777, so what is it you're doing anyway
23:45 codepython777 Hyratel1: exactly what you did - at a smaller scale, and with 4 motors
23:46 codepython777 choonway: am not sure that will fit the motor i linked, and the 8" wheel that Hyratel1 linked
23:46 Hyratel1 https://www.sparkfun.com/products/13166
23:46 Hyratel1 get yourself a kit
23:46 Hyratel1 learn to do the thing
23:47 codepython777 Hyratel1: i need to carry around 20lb
23:47 Hyratel1 learn
23:47 Hyratel1 to
23:47 Hyratel1 do
23:47 Hyratel1 the
23:47 Hyratel1 thing first
23:47 codepython777 what do you learn from that kit?
23:47 Hyratel1 how the parts interact
23:47 Hyratel1 you can scale up
23:48 codepython777 I've made kits. When i try to scale, and change the parts - i cant find parts - at least not cheap
23:48 Hyratel1 then ask the right questions
23:48 Hyratel1 first
23:48 Hyratel1 "how big is my payload"
23:48 codepython777 motor mount $42 - motor $60 - wheel $7 - wheel mount - not available?
23:48 Hyratel1 eh?
23:48 Hyratel1 what kits ahve you worked with
23:50 codepython777 Hyratel1: the kit you linked uses 2 motors. I want to use 4.
23:50 Hyratel1 why?
23:50 codepython777 Because its simpler design? - Assuming i can get reliable motors?
23:50 Hyratel1 wrong
23:51 Hyratel1 it's more complex to wire up 4 motors
23:51 codepython777 so you are telling me using sprockets with chains is more reliable?
23:51 Hyratel1 do you need 4 wheel drive?
23:51 Hyratel1 and you haven't been answering my quesitons
23:51 codepython777 yes, i want to build all terrain - so thats another reason
23:51 Hyratel1 which I ask for good reasons
23:51 Hyratel1 "how big is my payload"
23:51 codepython777 20lb
23:52 Hyratel1 wrong
23:52 Hyratel1 BIG
23:52 Hyratel1 dimensions
23:52 Hyratel1 size
23:52 Hyratel1 not weight
23:52 codepython777 ah ok
23:52 codepython777 24" x 12" x 6" - roughly
23:53 Hyratel1 odd proportion
23:53 Hyratel1 what is it
23:54 codepython777 its a bunch of parts inside it sensors and communication system
23:54 codepython777 i need to move it around ad do measurements
23:55 Hyratel1 you're being cagey
23:55 Hyratel1 getting useful information to use to help you is like pulling teeth
23:55 Hyratel1 if you want help, you have to volunteer the information
23:55 Hyratel1 what kind of comm gear is it anyway
23:55 Hyratel1 why is it so large and massive
23:56 codepython777 Hyratel1: Peace and out :)
23:56 Hyratel1 eh?
23:57 codepython777 you are asking questions which are orthogonal to what i am looking for
23:57 codepython777 what the payload contains has nothing to do with the design of the bot
23:58 Hyratel1 that part's simple curiosity
23:58 Hyratel1 but it leads into why it's such a damn weird shape
23:59 codepython777 Its just a small suitcase :)
23:59 Hyratel1 'just'
23:59 Hyratel1 can you use the suitcase as your chassis?
23:59 Hyratel1 also