#robotics Logs
Sep 02 2018
#robotics Calendar
12:14 AM Jak_o_Shadows: hey, the tests, without using any of my own code, works
02:45 AM VansFannel: Hi!
02:45 AM VansFannel: I'm 43 years old and I want to learn robotics. Do you recommend me Lego Mindstorms ev3? Thanks.
02:48 AM rue_shop4: no
02:49 AM rue_shop4: VansFannel, robotics is made of LOTS of things
02:49 AM rue_shop4: do you build things now?
02:50 AM VansFannel: No. I've just started and I'm learning how to use ROS.
02:51 AM rue_shop4: do you have any specific goals?
02:51 AM VansFannel: yes, learn robotics.
02:51 AM VansFannel: I want to do something with my hands, instead of using a simulator.
02:52 AM rue_shop4: ok, there is no such thing as robotics, its a virtual collection, it consists of electronics, mechanics, and computer programming. do you know any of these already?
02:52 AM VansFannel: I'm a software engineer.
02:52 AM VansFannel: I've been working as a programmer for 18 years.
02:52 AM rue_shop4: I hear that you understand programming.
02:52 AM rue_shop4: ok, you need to focus on electronics and mechanics
02:53 AM VansFannel: ok
02:53 AM rue_shop4: can you summeraize what you know about these two things?
02:53 AM VansFannel: Nothing.
02:53 AM rue_shop4: ok.
02:53 AM rue_shop4: do you have a set of pliers?
02:53 AM VansFannel: No
02:54 AM rue_shop4: ok, do you have a set of screwdrivers?
02:54 AM VansFannel: yes
02:54 AM rue_shop4: ok, do you have a soldering iron?
02:54 AM VansFannel: no
02:54 AM rue_shop4: ok, do you have a hacksaw?
02:55 AM VansFannel: No, I live in a small flat. I only have screwdrivers.
02:55 AM rue_shop4: ok.
02:55 AM rue_shop4: processing....
02:55 AM rue_shop4: is you goal to build, or program robots?
02:56 AM VansFannel: Maybe program, and also do something with my hands.
02:56 AM rue_shop4: ok
02:57 AM rue_shop4: would you like to learn to construct, or design and construct robots?
02:58 AM VansFannel: I'm studing a master's degree in artificial intelligence and I'm sure that I will have to construct something to test my investigation.
02:58 AM rue_shop4: ah, you would like to help me build my swarm, perfect.
02:59 AM rue_shop4: I'm working on porting myself to an electromechanical platform, if my existance weren't at steak, it would not be worth the effort.
02:59 AM rue_shop4: so, tell me what languages you know roughly in the order you learned them
03:01 AM VansFannel: I use C#, but I want to use C++. I also know a bit of Python.
03:02 AM rue_shop4: ok, give me two rough budgets, one for tools, one for parts
03:04 AM VansFannel: I don't know.
03:05 AM VansFannel: I haven't thought about it.
03:05 AM rue_shop4: an example would be something like tools: $100 parts: $40
03:07 AM VansFannel: I have to talk with my professor about what I have to construct and then I will know what I need and the budgets.
03:07 AM rue_shop4: ah
03:08 AM rue_shop4: then you can use school budget
03:08 AM rue_shop4: which is firtually unlimited
03:08 AM rue_shop4: virtually even
03:08 AM rue_shop4: but, if school is a factor, so is timeline
03:08 AM rue_shop4: how long do you have to complete a project
03:09 AM VansFannel: I will ask about the school budget.
03:09 AM VansFannel: Six months.
03:09 AM VansFannel: But I think that Lego will be useful to learn about how to construct something and how to use sensors without so much effort.
03:09 AM rue_shop4: ok, see, if your doing it yourself in spare time, getting parts from china saves a lot of money, but it can take months to get materials
03:10 AM rue_shop4: if your doing it at a school, they will already have materials, but buying a few hundred dollars of extra stuff is no big deal, which means you can buy from places that have horrid prices, but will get you the supplies fast
03:11 AM rue_shop4: it will also mean you have access to thousands of dollars of tools
03:11 AM rue_shop4: which saves money
03:12 AM VansFannel: Ok. Thanks a lot for your advice, it helps a lot.
03:13 AM VansFannel: Maybe, I'll come back here very often to get advice.
03:24 AM VansFannel: I have to go. Bye. rue_shop4, thanks.
06:16 AM VansFannel: Hi!
06:17 AM VansFannel: I'm 43 years old and I want to start learning robotics. Do you recommend me to start with Lego Mindstorms ev3? Thanks.
06:46 AM Jak_o_Shadows: Someone needs to tell them that most of us stick around for most of the day
07:24 AM _unreal_: Jak_o_Shadows, vansfannel is a bot
07:25 AM Jak_o_Shadows: Well, passes the turing test then.
09:02 AM VansFannel: I'm new in ROS and Gazebo, and I want to control a robot in Gazebo using keyboard, how can I do it? Thanks.
09:22 AM EcoRVII: Hey guys, I just got started with my robot arm and trying to implement very simple inverse kinematics for a 2D 2 arm setup. I'm fine with doing the 2 circle intersection to get the angles required to reach my desired endpoint, but unfortunately the actual rotational point of my second arm is not right at the beginning of the arm. So there is actually an offset for my endeffector. I'm not so sure how I would incorporate that end e
09:22 AM EcoRVII: intersection equation. here is a pic for clarity: https://imgur.com/a/Yn0Qqze
09:25 AM EcoRVII: Please let me know if I should clarify my sketsch
10:07 AM EcoRVII: oh, got it. I'm stupid.
10:58 AM rue_bed: huh
01:13 PM SpeedEvil is now known as Guest75
03:49 PM BitEvil is now known as SpeedEvil
04:26 PM Tom_L: ``
04:26 PM Tom_L: ``
06:53 PM rue_shop4: the cnc machine always seem to take more work to do a job on
07:04 PM _unreal_: ?
07:04 PM rue_shop4: than just printing something on the 3d printer
07:11 PM Tom_L: they are accurate however i agree setup takes a while but they were intended for repetetive work
07:15 PM rue_shop4: have you ever done an encoder wheel with your cnc?
07:17 PM Tom_L: no
07:17 PM Tom_L: i probably could
07:17 PM Tom_L: i know others have
07:18 PM Tom_L: if you need a file i can make one for you
07:20 PM orlock: i did one on the printer
07:20 PM Tom_L: i've printed them before
07:20 PM orlock: hmm
07:20 PM orlock: when i have time i'll do one that mounts on a stepper shaft just to test accuract
07:22 PM orlock: i thought i cooked a stepper motor, seems ok yay
07:22 PM orlock: i was fiddling with the trimpot, didnt realise battery was flat
07:22 PM orlock: changed over to a plugpack, was wondering why it was getting hot
09:23 PM rue_shop4: ok using the cnc machine to drill a centered 5mm hole in something was a completel waste of time
09:23 PM rue_shop4: accep to learn that the 3,175mm bits I got from china are really 3mm
09:24 PM rue_shop4: I suppose thats "close enough"
09:25 PM Tom_L: how did you go about centering it?
09:25 PM rue_shop4: I milled a pocket to put it in
09:26 PM rue_shop4: after discovering the hole was the wrong size, and that the bit was only 3mm , I lost the ONLY peice I had to do this with
09:26 PM rue_shop4: aka, complete waste of time
09:26 PM rue_shop4: back to 3d printing them
09:26 PM Tom_L: what was it?
09:26 PM rue_shop4: encoder wheel
09:31 PM Tom_L: for the new mill?
09:32 PM rue_shop4: no
09:32 PM rue_shop4: well, for everything
09:32 PM rue_shop4: but for the new freq gen I'm making
09:32 PM rue_shop4: the crap mechanical encoders from china have used up all my pantience
09:33 PM Tom_L: how many cpr?
09:33 PM rue_shop4: I need flipping OPTICAL encoders for $0.50 ea
09:33 PM rue_shop4: and I dont care if their only 20ppr
09:33 PM Tom_L: i thought kat had a bunch in those cable boxes she has
09:33 PM rue_shop4: mechanical
09:33 PM Tom_L: mmm
09:33 PM rue_shop4: which are JUNK
09:34 PM rue_shop4: not even china equip can make them work reliably
09:35 PM Tom_L: for selector switches or something else?
09:35 PM rue_shop4: everything
09:35 PM rue_shop4: I need them for everything
09:36 PM rue_shop4: I can design around whatever resolution they have
09:36 PM rue_shop4: $0.50 and OPTICAL
09:37 PM rue_shop4: do you know, for a 7mm ream what hole size I use?
09:37 PM Tom_L: just a sec
09:38 PM orlock: rue_shop4: Mice?
09:38 PM rue_shop4: orlock, nope, I have lots of parts of them in my "try to use" bin tho
09:38 PM Tom_L: letter H
09:39 PM Tom_L: 7mm is .2756 and H is .2660
09:39 PM rue_shop4: ok
09:39 PM Tom_L: about .010
09:39 PM Tom_L: that's about what you want
09:39 PM Tom_L: maybe up to .020 but i try not to
09:40 PM Tom_L: letter I is only .272 which isn't enough
09:41 PM Tom_L: 17/64 ( .2656 ) would do if you don't have letter drills
09:45 PM rue_shop4: oh I got most of it
09:45 PM rue_shop4: just not a full 0.1mm set of drillbits
09:46 PM rue_shop4: I have 0.5 and a few misc
09:47 PM Tom_L: 6.8 would be close if you have one
09:47 PM Tom_L: i've got a few assorted metric reamers but no idea which ones
09:48 PM orlock: never heard of letter drill bits before
09:48 PM orlock: numbers not good enough?
09:48 PM rue_shop4: when they ran out of letters they went to numbers
09:48 PM rue_shop4: aka #80
09:48 PM Tom_L: they kinda fill in where number and fraction lack
09:48 PM Tom_L: number are smaller
09:56 PM orlock: so thy not just call a .2660 a .2660?
09:57 PM orlock: to ohard to write on the shaft i guess?
10:05 PM Tom_L: https://www.imperialsupplies.com/pdf/I_DrillSizeDecimalEquivalent&TapDrillChart.pdf
10:14 PM rue_shop4: ok, printed encoder, with 2 coats of black paint (3d plastic is IR transparent)
10:14 PM rue_shop4: npn transistor, 4.7k@5v running the led, 1M shunt resistor on the npn,
10:15 PM Tom_L: pics
10:15 PM rue_shop4: I need a way to adjust the phase of the second interrupter
10:19 PM orlock: rue_shop4: eh, didnt know that it was IR transparent
10:19 PM Tom_L: lots of things are
10:19 PM Tom_L: inkjet ink is however laser toner isn't
10:20 PM rue_shop4: I'v not found a colour of PLA that isn't pretty transparent to IR light
10:20 PM orlock: shit, mine seemed to work ok..
10:20 PM Tom_L: what diameter wheel?
10:21 PM rue_shop4: 20mm
10:23 PM Tom_L: http://tom-itx.no-ip.biz:81/~webpage/cnc/new_pulleys/old_pulley2.jpg
10:23 PM Tom_L: similar to that disk?
10:23 PM rue_shop4: yes but smaller :)
10:23 PM Tom_L: off a printer
10:24 PM rue_shop4: yea, I have a lot of them from misc stuff
10:24 PM rue_shop4: thats not helping, I need soehting I can design once and make lots of
10:24 PM Tom_L: yeah
10:24 PM Tom_L: what material were you using on the cnc for it?
10:24 PM rue_shop4: an optical wheel from a mouse
10:24 PM rue_shop4: I was trying to recut it
10:24 PM Tom_L: oh
10:25 PM Tom_L: you were trying to center the hole
10:26 PM rue_shop4: no, I was shaving off the hub and cutting a 5mm hole in the middle
10:26 PM rue_shop4: there were two, the other one shattered when I tried to put it in the pocket
10:27 PM rue_shop4: I can make a working disc
10:27 PM rue_shop4: I have a working interuption circuit
10:27 PM rue_shop4: I need to be able to hold a shaft, and position the interrupters
10:28 PM Tom_L: hold it in what way?
10:28 PM rue_shop4: I have some 10mm hex bolts, that I can drill out 7mm, and use the 7mm-3mm ball bearings I got
10:28 PM Tom_L: to machine or to use
10:29 PM rue_shop4: that gives me a 5mm shaft, with bearings, in a 10mm bolt-thru pot-like panel interface
10:29 PM Tom_L: i see
10:29 PM Tom_L: http://tom-itx.no-ip.biz:81/~webpage/cnc/new_pulleys/spindle_enc1.jpg
10:29 PM Tom_L: something like those encoders
10:30 PM rue_shop4: one of my ideal results would be something the size of a 24mm pot, but thats an optical enocder
10:30 PM Tom_L: http://tom-itx.no-ip.biz:81/~webpage/cnc/new_pulleys/spindle_enc6.jpg
10:30 PM rue_shop4: something to that affect, yes
10:32 PM Tom_L: i only got 4 of those
10:32 PM Tom_L: off some old medical equipment
10:32 PM rue_shop4: yup
10:32 PM Tom_L: but it was ideal for the spindle
10:34 PM Tom_L: 7mm in a 10mm bolt... does that give you enough wall to tighten the threads without pulling them apart?
10:34 PM Tom_L: 1.5mm per side
10:34 PM Tom_L: not much
10:41 PM Tom_L: https://www.usdigital.com/products/e4t
10:42 PM Tom_L: i know you don't want that but i stumbled across it
10:44 PM Tom_L: $25 ea
10:47 PM Tom_L: https://uk.farnell.com/panasonic-electronic-components/eve-jbbf2020b/mechanical-encoder-gs-20cpr/dp/2284566
10:47 PM Tom_L: getting closer
10:53 PM Tom_L: https://www.e-motionsupply.com/product_p/mes3.htm
10:53 PM Tom_L: tiny
10:53 PM orlock: managed to properly defrost my fridge
10:53 PM orlock: fucking thing
10:53 PM orlock: it's got a single compressor/chiller
10:53 PM orlock: and uses a pai of fans and has some internal ducting
10:54 PM orlock: air returns were blocked solid with ice
11:20 PM rue_shop4: sorry, I'v been going thru the box of old rotary switches, learning how they were made
11:20 PM rue_shop4: over like 40 years, they were all made the same
11:23 PM Tom_L: the ones on my pendant have adjustable stops
11:32 PM zhanx: when that code says wtf and just wont work
11:32 PM zhanx: man just compile and work darn it!
11:45 PM rue_shop4: break it all down and start again
11:48 PM orlock: fuck cisco
11:48 PM orlock: seriously
11:49 PM rue_shop4: ?
11:49 PM orlock: i want to terminate a VPN on a cisco security device
11:49 PM orlock: but i want ot to use one of our IP's
11:50 PM orlock: not an ISP assigned IP
11:50 PM orlock: we have plenty, and they will never change
11:50 PM orlock: but the Cisco ASA wont let me
11:51 PM orlock: it will only let you use your IP on your "outside" interface
11:51 PM orlock: and it doesnt support secondary addresses
11:56 PM rue_shop4: DMZ?
11:57 PM rue_shop4: maybe a virtual dmz
11:58 PM rue_shop4: ARG, I took the 3jaw off
11:58 PM orlock: nah, it's like they have intentionally made it unworkable
11:58 PM rue_shop4: see if I can get the plate and centre out of the head
11:58 PM orlock: unless you buy another box
11:58 PM rue_shop4: you cant make a virtual dmz with a fixed ip that you do soemthing with
11:59 PM rue_shop4: dont cisco scerw up their packet routing if an external interface has the same network as an internal one?