#robotics Logs

Mar 05 2017

12:51 AM anniepoo_: ok, not enough room in snail's neck
12:54 AM anniepoo_: going to have to use remote servos
12:54 AM anniepoo_: 8cP friction, loss of rigidity, poor control authority, power consumption
12:54 AM anniepoo_: complexity, weight
12:54 AM anniepoo_: I'm pretty much stuck putting the sensor head right where all the plumbing goes through
01:18 AM rue_bed: well, with the 1/8 bit, no cooling, the motor on the cnc stalled and the machine didn't seem to have broken as it bent the cutter and dragged it thru the aluminum block
01:19 AM rue_bed: so, needs cooling/lube
01:19 AM rue_bed: need an auto luber
01:19 AM rue_bed: air is enough for the 1mm carbide bit
01:20 AM rue_bed: I'm wondering if I should rewind the motor to a higher voltage
01:20 AM rue_bed: 24A is kinda crazy
01:26 AM zhanx: rue_bed: where is my 3d printer?
01:39 AM anniepoo_: http://partyserver.rocks/anniepoo/snailxray.png
01:39 AM anniepoo_: New latest snail
01:48 AM SpeedEvil: I choose to believe the purple things are a multi-launch rocket array
01:49 AM SpeedEvil: http://cdn-4.olive-drab.com/images/id_mlrs_700_03.jpg
01:57 AM anniepoo_: no, they're 9g servos to drive the neck
01:59 AM anniepoo_: 8cD wondering if bell cranks are my new best friend
02:01 AM SpeedEvil: :)
02:01 AM SpeedEvil: Why so many?
02:01 AM SpeedEvil: Are some in parallel?
02:01 AM SpeedEvil: Or is it overactuated for simplicity
02:02 AM SpeedEvil: I guess that's the same thing
02:02 AM anniepoo_: just lots of parts to move
02:04 AM anniepoo_: I could make the neck underactuated
02:04 AM anniepoo_: but it restricts motion without a lot of gain
02:06 AM anniepoo_: 3 for eyes, 2 for mouth, 9 for head, 6 for 2 neck sections
02:06 AM anniepoo_: 3 for eyes, 2 for mouth, 3 for head, 6 for 2 neck sections
02:06 AM SpeedEvil is now known as Guest99214
02:07 AM anniepoo_: evening snert
02:08 AM BitEvil is now known as SpeedEvil
02:17 AM anniepoo_: ok, I'm logged into youtube as playing iwht prolog
02:18 AM anniepoo_: sorry ww
06:01 AM Snert: hiya annie
10:02 AM robopal: What do you do with the NiMh batteries that you don't use for a long time? Do you recharge them periodicaly?
10:30 AM ace4016: you don't want to let them completely drain, so as long as you monitor them, they should be fine
10:38 AM synja: ^^ you will never be able to use them again
10:38 AM synja: although most of them have a BMS which won't allow it to be discharged that low
11:01 AM robopal: synja, no I am talking about individual batteries, AA,AAA not battery packs
11:11 AM ace4016: NiMH doesn't discharge that quickly. they don't have memory effect so there's no point in discharging them completely, but you probably don't want them to completely discharge as the next cycle can permanently damage the battery iirc. they can sit for a few years on the shelf without becoming fully discharged or so
11:44 AM SpeedEvil: 20% a month is common for NiMH
11:44 AM SpeedEvil: they're nearly flat at a year.
11:45 AM SpeedEvil: And yes, recharge at least every 6 months
11:45 AM SpeedEvil: Or store in freezer.
11:48 AM rue_bed: I have a large bunch of lead-acids, they are a pain to maintain
12:01 PM robopal: I have lost my box with the ceramic capacitors :-(
12:02 PM robopal: I hope it will turn up when I do a cleanup...
12:17 PM rue_bed: I find cleaning up to find things a great way to go
07:50 PM rue_shop3: I went scrounging for steel, got lots of good stuff
07:50 PM rue_shop3: including some steel
07:50 PM rue_shop3: (only about 250lbs or so)
07:53 PM Tom_L: poor S10
07:54 PM Tom_L: aarh
07:54 PM Tom_L: g
07:58 PM rue_shop3: yea, I think I owe it new rear springs
07:59 PM Tom_L: apparently this app won't run on that MB
08:00 PM Tom_L: i just keep having more and more problems...
08:01 PM Tom_L: the NTVDM CPU has encountered an illegal instruction.
08:01 PM Tom_L: wtf is that about?
08:05 PM SpeedEvil: https://twitter.com/elonmusk/status/838558471972741120 It's real! He's got hats!
08:13 PM rue_house: Tom_L, whats it written in?
08:26 PM Tom_L: clipper
08:26 PM Tom_L: apparently there's some difference between 5.2 and 5.3
08:27 PM Tom_L: 5.3 has a few more file manipulation commands and apparently one of them is causing the problem
08:27 PM Tom_L: i removed the command and it's working under 5.2 again
08:27 PM Tom_L: i'd like to use 5.3 if i can
08:27 PM Tom_L: still testing it out
08:28 PM Tom_L: checks to make sure a directory exhists...
08:28 PM Tom_L: guess i'll have to do it another way
08:30 PM Tom_L: they use different linkers too
08:31 PM Tom_L: ahh... it's the linker at fault
08:32 PM Tom_L: maybe i need to figure how to set that up better than it is as far as memory management
08:33 PM Tom_L: yeah the old linker handles it fine
08:34 PM Tom_L: always some damn thing...
08:34 PM Tom_L: i'm not sure what to change with the linker settings though
08:35 PM Tom_L: maybe it's not swapping enough code out to disk
08:37 PM rue_shop3: ah, clipper isnt a language you can just port over to another OS
08:38 PM Tom_L: no but the guys that use it wrote a windows conversion for it
08:38 PM Tom_L: i've been working on the windows code to but i don't like the windows interface of ti
08:38 PM Tom_L: it
08:38 PM rue_shop3: is it just an sql database?
08:38 PM Tom_L: no
08:38 PM Tom_L: dbase
08:38 PM Tom_L: it has replaceable drivers though
08:38 PM Tom_L: i think it could use sql
08:39 PM Tom_L: i know it can use firefox
08:39 PM Tom_L: hah, the brouser stole their name
08:43 PM Tom_L: i can use OVERLAY DYNAMIC or FIXED
08:43 PM Tom_L: where FIXED will pre'allocate a block for code use
08:44 PM Tom_L: how much ram can dos use at a time? 64k?
08:44 PM Tom_L: as it is, the linker overlay is using 40 for code by default
08:45 PM Tom_L: 40k
08:46 PM rue_shop3: dos can only access 640k per app
08:46 PM Tom_L: in 64k blocks though isn't it?
08:46 PM Tom_L: or the whole 640k at once
08:46 PM rue_shop3: oh yea, prolly
08:47 PM rue_shop3: I think I got some good stuff to make another cnc from
08:47 PM Tom_L: cool
08:47 PM rue_shop3: still have a slider problem tho
08:47 PM Tom_L: i rewrote my code so i can print most things from file now
08:47 PM Tom_L: as an option
08:48 PM rue_shop3: I wonder if freedos can do pnp
08:48 PM Tom_L: i doubt it
08:49 PM Tom_L: if you find out different let me know
08:49 PM rue_shop3: I cant even motivate myself to get the metal out of the truck
08:49 PM Tom_L: open the back and drive uphill real quick
08:49 PM Tom_L: or back up and stop quick
08:50 PM rue_shop3: na, I'd scratch the paint
08:50 PM Tom_L: pfft
08:50 PM rue_shop3: :)
08:50 PM rue_shop3: I found some 1/2" plate that I think will make a good base
08:50 PM Tom_L: i'm not sure which one of these linker options to use
08:50 PM orlock: i tried doing that last week
08:50 PM orlock: didnt have enough space to get to speed
08:50 PM orlock: had to get out and throw shit out of the back
08:50 PM Tom_L: i've got a 1/2" plate work table
08:51 PM Tom_L: i love it
08:51 PM orlock: (council rubbish collection)
08:51 PM Tom_L: rue_shop3, what do you use to cut the steel?
08:51 PM rue_shop3: orlock, would you PLEASE decide if your in the USA or Australia?
08:51 PM rue_shop3: horzontal band saw
08:52 PM Tom_L: i found abrasive cutoff blades work really well
08:52 PM rue_shop3: yea, $$
08:52 PM Tom_L: quicker than a saw
08:52 PM Tom_L: not too bad if you look around
08:52 PM rue_shop3: its an auto, you just set and forget
08:52 PM Tom_L: yeah i wish i had one
08:53 PM rue_shop3: and, hopefully, you dont try to cut thru a hard drive and find out 4 hours later its taken all the teeth off on a headend bearing
08:53 PM rue_shop3: :(
08:53 PM rue_shop3: I should order more blades tho
08:53 PM Tom_L: ever weld em?
08:53 PM rue_shop3: I'm down to 1 spare
08:54 PM Tom_L: i've done that a few times
08:54 PM rue_shop3: yea, at school :/
08:54 PM rue_shop3: I have a spot welder, but cant recall all how to do it
08:54 PM rue_shop3: I think you weld, grind, and temper a few times
08:55 PM rue_shop3: I can get blades from china for about $14ea iirc
08:55 PM Tom_L: hahahaha... it's even got a 'MURPHY' switch
08:55 PM rue_shop3: ?
08:55 PM Tom_L: the linker
08:55 PM rue_shop3: hmm
08:56 PM Tom_L: it lets you burn runtime settings right into the exe
08:56 PM Tom_L: environment vars
08:58 PM Tom_L: time for a break..
08:58 PM Tom_L: my head hurts
08:58 PM Tom_L: at least i know it's a linker setting now and not code
09:00 PM rue_shop3: arg, sometimes I'm just not in the mood to do anything, I need a pill for that
09:00 PM Tom_L: no, sometimes you just need to do nothing
09:01 PM Tom_L: it's your body talking to you
09:01 PM rue_shop3: yea, its upset cause I'm trying to obsolete it
09:02 PM Tom_L: i wonder if the old compiler can use the new libraries..
09:02 PM Tom_L: i used to know how to pull functions from a library and make a new lib from them
09:03 PM Tom_L: i've forgotten how
09:05 PM Tom_L: ok let's see how bad this botches it up
09:06 PM Tom_L: yeah i was afraid of that... undefined symbols
09:06 PM Tom_L: even using the newer include files
09:16 PM branjb: turns out getting absolute orientation from an IMU is a non trivial task
09:16 PM rue_shop3: hah
09:16 PM rue_shop3: noise problem?
09:16 PM rue_shop3: screwing up the integrator?
09:17 PM branjb: right now? just trying to find a good reference to convert the raw data into current position
09:18 PM branjb: i figured it was like 10 lines of code in something like cleanflight or any of those opensource quadcopter packages
09:18 PM branjb: it's more like hundreds of lines of code haha
09:21 PM SpeedEvil: Kalman filters are fun.
09:21 PM SpeedEvil: Absolute orientation isn't so bad.
09:21 PM SpeedEvil: Position - you're going to need another source too.
09:22 PM branjb: yeah, I just didn't know what I didn't know; figured it was a few lines of code converting raw data to measurable data
09:33 PM rue_shop3: I have to take a good look at how kalman filters work some time
09:33 PM SpeedEvil: They are conceptually simple, once you understand that a gaussian distribution multipled by another gaussian distribution is another gassian.
09:34 PM SpeedEvil: And that you can model sensor errors as gaussians.
09:34 PM rue_shop3: mmmhmmm
09:34 PM SpeedEvil: So, initial state, plus sensor input = new state.
09:34 PM rue_shop3: known patterns of error then
09:35 PM SpeedEvil: The maths are considerably more involved.
10:42 PM rue_house: I need to get my force feedback controller working
10:49 PM branjb: https://vid.me/H4UQ
10:49 PM branjb: no PID, super crude, but hours of work haha
10:54 PM rue_house: ok, whats it doing?