#garfield Logs
Sep 22 2022
#garfield Calendar
08:08 PM rue_shop3: big cnc
08:17 PM rue_shop3: in order to get the resolution I want, I need to have about 100:1 ratio motor to drive system
08:17 PM rue_shop3: and I have to control the motor within about 5 degrees, which I'm sure I can do
08:17 PM rue_shop3: but, the motor would need to peak out at 16.6kRPM on full jog
08:17 PM rue_shop3: BUT, the peak torque on it should only be 0.056Nm
08:17 PM rue_shop3: 0.13HP
08:17 PM rue_shop3: so, a vacuum cleaner motor should be ok
08:17 PM rue_shop3: but it also puts me back into the ~170VDC motor driver category
08:25 PM Tom_L: gear reduction?
08:25 PM rue_mohr: gonna use belts
08:25 PM Tom_L: otherwise you're really gonna be slinging the chain
08:25 PM rue_mohr: mush instead of lash
08:25 PM rue_mohr: yea thats a good point too
08:25 PM Tom_L: even so, belts have a speed limit
08:25 PM rue_mohr: gonna be small belts
08:26 PM rue_mohr: few in parallel I imagine
08:26 PM rue_mohr: 10:1 is a huge ratio too
08:26 PM rue_mohr: 22cm:2cm
08:26 PM Tom_L: 11:1
08:26 PM rue_mohr: come to think of it thats still a problem
08:26 PM rue_mohr: the drive shaft is larger than that
08:27 PM rue_mohr: 37mm shaft
08:27 PM Tom_L: i saw
08:27 PM rue_mohr: oh but it only needs the big one
08:27 PM rue_mohr: so thats ok
08:27 PM rue_mohr: if I'm using 3/16" round seals for belts
08:28 PM rue_mohr: how many do you think I should parallel up for 0.13HP
08:28 PM rue_mohr: 4? 5?
08:28 PM Tom_L: 1
08:28 PM rue_mohr: needs to be a backup tho
08:28 PM Tom_L: you're gonna rip the teeth off it
08:28 PM rue_mohr: so, 2 min
08:28 PM rue_mohr: not toothed
08:28 PM Tom_L: startup torque
08:28 PM Tom_L: even worse
08:29 PM rue_mohr: hmm I wonder
08:29 PM Tom_L: you'll burn the crap out of it like i did on the stock sherline belt
08:29 PM rue_mohr: 0.13hp you think I'll slip?
08:29 PM rue_mohr: torque is 0.056Nm
08:29 PM rue_mohr: thats
08:30 PM Tom_L: 16k rpm must have a fast ramp up
08:30 PM Tom_L: you're gonna rip the teeth off it
08:30 PM rue_mohr: 0.04foot-lbs
08:30 PM rue_mohr: ah, hmm
08:31 PM Tom_L: GT3 series are the best form
08:31 PM Tom_L: 5mm pitch
08:31 PM rue_mohr: $$$$ :/
08:32 PM rue_mohr: and I cant print these, so more $$$$
08:32 PM rue_mohr: (print the pullies)
08:32 PM Tom_L: rack & pinion
08:32 PM rue_mohr: the tooth belts and pullies would be like $700 right there
08:32 PM rue_mohr: yea, rack and pinion is ~$800
08:33 PM rue_mohr: I might try to cut my own rack when its basically working
08:33 PM Tom_L: rope looped around a pulley a couple times like the old dial radios did way way back
08:33 PM rue_mohr: did you see the chain and cable I set up?
08:33 PM Tom_L: rope/steel cable
08:33 PM Tom_L: i dunno
08:34 PM rue_mohr: you ok, you sound like you ache
08:34 PM rue_mohr: ?
08:34 PM Tom_L: life keeps changing
08:35 PM Tom_L: kid starts a new job next week
08:35 PM Tom_L: $6 more an hour doing the same thing
08:35 PM rue_mohr: nice
08:35 PM rue_mohr: http://ruemohr.org/~ircjunk/tempimage/p1250440.jpg
08:35 PM rue_mohr: http://ruemohr.org/~ircjunk/tempimage/p1250441.jpg
08:35 PM rue_mohr: http://ruemohr.org/~ircjunk/tempimage/p1250443.jpg
08:35 PM rue_mohr: http://ruemohr.org/~ircjunk/tempimage/p1250444.jpg
08:35 PM rue_mohr: its hard to get in one shot
08:35 PM rue_mohr: there are a few
08:36 PM rue_mohr: :/ I didn't show the cable<->chain interface
08:36 PM rue_mohr: but its there
08:36 PM Tom_L: lots of chain
08:36 PM rue_mohr: yea
08:36 PM rue_mohr: its tight enough its staying up
08:36 PM rue_mohr: which is something I was worried about
08:36 PM Tom_L: it will stretch
08:36 PM rue_mohr: the cable is a spring
08:36 PM rue_mohr: it'll take up
08:37 PM rue_mohr: the feedback will be seperate off the carriage
08:37 PM rue_mohr: so the drive can do whatever it wants
08:37 PM Tom_L: i recognize a couple of the parts
08:37 PM rue_mohr: yea, its teken freaking years :/
08:38 PM rue_mohr: but I'm under $240 still
08:38 PM rue_mohr: er, I might be under $100
08:38 PM Tom_L: where did the chain come from?
08:39 PM rue_mohr: bike store :/
08:39 PM rue_mohr: its like $37 in chain
08:39 PM Tom_L: did he ask what size bike it was going on?
08:39 PM rue_mohr: and I used new bearings
08:39 PM rue_mohr: heh
08:39 PM Tom_L: i put you onto the bearings
08:39 PM rue_mohr: I start by telling them its for a robot
08:39 PM rue_mohr: gets rid of all the stupid questions
08:40 PM Tom_L: you went out that day and got them
08:40 PM rue_mohr: :)
08:40 PM rue_mohr: all the castings worked out
08:40 PM Tom_L: i forgot what i told you
08:40 PM Tom_L: wheel bearings?
08:40 PM rue_mohr: I got 3d printed stuff going on there too
08:40 PM rue_mohr: I dont recall, a great size tho
08:41 PM Tom_L: i haven't done anything in weeks
08:41 PM Tom_L: did the git thing but that's about it
08:41 PM rue_mohr: I have to cough up a dcmotor servo with a stepper motor interface
08:42 PM rue_mohr: and I'm totally not sure on performance requirements
08:43 PM rue_mohr: getting scary tho, looks like, with what I have, I need to drive the motors at ~150+ V
08:43 PM rue_mohr: so, 3 high voltage motor drivers
08:43 PM Tom_L: iirc my spindle is ~300v
08:43 PM Tom_L: thru the vfd
08:44 PM rue_mohr: huh, motors are like less than 100w tho
08:44 PM rue_mohr: so I could use computer power supplies as DC supplies
08:44 PM rue_mohr: the primary side
08:44 PM rue_mohr: maybe i'll put ground fault protectors on that...
08:45 PM Tom_L: takin some time off?
08:45 PM rue_mohr: I left
08:45 PM Tom_L: i know
08:45 PM rue_mohr: so yea, I'm unwinding for a bit
08:46 PM rue_mohr: I'm comming down from being really badly stressed out
08:46 PM rue_mohr: and I can see why
08:46 PM rue_mohr: my hours were down so bad from lack of work, that working full time the last period triggered my bank page to say "Your last paycheque is unusually high"
08:46 PM rue_mohr: 8S
08:47 PM rue_mohr: down 20% so far this year
08:48 PM Tom_L: i think everything is slower than a couple three yrs ago
08:48 PM rue_mohr: and, when I was digging, I'm not the only person who wasn't getting full time
08:48 PM rue_mohr: when I was calling around the crew asking if anyone needed help, there was a pretty dismal picture forming
08:50 PM rue_mohr: I need to rewrite my resume (cv)
08:51 PM rue_mohr: I was pondering an html document with embedded javascript
08:51 PM rue_mohr: :)
08:52 PM rue_mohr: 100:1
08:52 PM rue_mohr: not sure if I should try to cast them
08:52 PM rue_mohr: 16k 1600 160rpm
08:53 PM rue_mohr: doing the small pulley for 16k is ...eek
08:53 PM Tom_L: not a good idea
08:53 PM rue_mohr: balance that one for sure
08:53 PM rue_mohr: maybe not cast it...
08:53 PM Tom_L: no voids
08:53 PM rue_mohr: yes, not cast
08:53 PM rue_mohr: cast would be bad
08:54 PM rue_mohr: solid, heat shrunk on
08:55 PM Tom_L: what diameter?
08:55 PM rue_mohr: ~20mm
08:55 PM rue_mohr: which is not tooo bad
08:55 PM Tom_L: you'll burn up the belt
08:55 PM rue_mohr: just the speed alone prolly eh?
08:56 PM Tom_L: turning that small a radius at those speeds
08:56 PM Tom_L: friction alone would probably get it
08:56 PM rue_mohr: so
08:56 PM rue_mohr: at the drive shaft I need 160 rpm peak
08:57 PM rue_mohr: and for every 0.05 degrees of that shaft I need the motor to turn about 5 degrees
08:57 PM Tom_L: get an old transmission
08:57 PM rue_mohr: well, its 100:1 still,
08:57 PM rue_mohr: but I could probably find some gears for a first step
08:57 PM Tom_L: harmonic drive
08:57 PM rue_mohr: ooo
08:58 PM rue_mohr: I dont want to take it toooo low at once
08:58 PM rue_mohr: whats got a reduction drive from about 20krpm?
08:59 PM Tom_L: nothing i can think of
08:59 PM Tom_L: turbo jet
08:59 PM rue_mohr: closest I can think of is a drill
08:59 PM rue_mohr: ahaha
08:59 PM rue_mohr: then I should be going hydraulic!
09:00 PM rue_mohr: too bad I dont have access to plane parts
09:00 PM rue_mohr: or do I
09:00 PM rue_mohr: there is a shop that services hellicopters beside where I used to work
09:01 PM rue_mohr: I wonder how long between forced change outs of some kinda small pump on a jet engine
09:01 PM rue_mohr: could be pretty small displacement
09:01 PM Tom_L: auxillary power units
09:02 PM Tom_L: are jets too
09:02 PM rue_mohr: not familiar
09:02 PM Tom_L: on the planes
09:02 PM rue_mohr: k, but unless its a turnbine its not likley rated to 20krpm
09:03 PM Tom_L: https://www.pwc.ca/en/products-and-services/products/auxiliary-power-units
09:03 PM Tom_L: canada too
09:03 PM Tom_L: :)
09:03 PM rue_mohr: do you know if there is a place that deals scrap plane parts?
09:03 PM rue_mohr: ...
09:04 PM Tom_L: we used to have a bone yard here
09:04 PM Tom_L: i dunno where they moved it
09:05 PM rue_mohr: hmm
09:05 PM rue_mohr: doesn't help I'm not sure what I'm looking for
09:06 PM aandrew: that is a fucking huge CNC, wowza
09:07 PM aandrew: lol @ "what kind of bike did you say the chain was for"
09:07 PM Tom_L: big...
09:07 PM Tom_L: my kid runs one with a 300" X axis
09:07 PM rue_mohr: I had to use two bikes worth on each of the top and bottom
09:07 PM rue_mohr: its only 4x8
09:07 PM Tom_L: make it a printer and print a house
09:08 PM Tom_L: start saving milk cartons..
09:09 PM aandrew: Tom_L: sure, but it's not homemade is it?
09:09 PM aandrew: whenever I watch those huge gantry cranes I wonder if they're running gcode
09:10 PM rue_mohr: shinkage :P
09:10 PM aandrew: there's that mill operator on twitter near me who works on really big stuff too
09:13 PM rue_mohr: I suppose the peak jog doesn't *HAVE* to be 1m/s
09:13 PM rue_mohr: could wait a bit longer for it to traverse the table
09:13 PM rue_mohr: and its not like I have to have a high acceleration on anything
09:15 PM rue_mohr: I need to just do something and if it doesn't work, change it
09:16 PM aandrew: what kinds of things do you want to do with it?
09:16 PM rue_mohr: if this has taught me anything so far, its that the requirements before something doesn't work are REALLY LOW
09:16 PM rue_mohr: wood
09:16 PM rue_mohr: the target resoltuion is only 0.1mm
09:16 PM rue_mohr: but that accurate to 0.05 or so
09:18 PM rue_mohr: its for things like toolboxes, and templates for casting
09:18 PM rue_mohr: probably some arcade machine parts
09:18 PM rue_mohr: furniture
09:18 PM BloodMoon: hey rue
09:18 PM rue_mohr: hey
09:19 PM rue_mohr: finish your tractor
09:19 PM rue_mohr: :)
09:19 PM BloodMoon: do you have your ansi escape sequence based functions on IrcJunk?
09:19 PM BloodMoon: for finding term size and shit
09:19 PM rue_mohr: oh
09:19 PM rue_mohr: hmm
09:19 PM rue_mohr: if not maybe github, lets see
09:20 PM rue_mohr: 40 repos!
09:20 PM aandrew: oh I did that too
09:20 PM aandrew: wtf was it
09:21 PM rue_mohr: hmm
09:22 PM rue_mohr: the problem was, you need a complete state machine to parse back the answers
09:22 PM BloodMoon: Well TITS!
09:22 PM Tom_L: aandrew, no not even close
09:22 PM Tom_L: 30k rpm spindle
09:22 PM Tom_L: 175 hp
09:23 PM rue_mohr: thats a lot of coolant
09:23 PM rue_mohr: BloodMoon, doesn't look like I did, let me see if I can find the code
09:24 PM Tom_L: esc seq for what?
09:24 PM BloodMoon: yes please :D
09:24 PM rue_mohr: int getWindowSize(int *rows, int *cols) {
09:24 PM rue_mohr: struct winsize ws;
09:24 PM rue_mohr:
09:24 PM rue_mohr: if ((ioctl(STDOUT_FILENO, TIOCGWINSZ, &ws) == -1) || (ws.ws_col == 0)) {
09:24 PM rue_mohr: return -1;
09:24 PM rue_mohr: } else {
09:24 PM rue_mohr: *cols = ws.ws_col;
09:24 PM rue_mohr: *rows = ws.ws_row;
09:24 PM Tom_L: i've likely got some old hp books
09:24 PM rue_mohr: return 0;
09:24 PM rue_mohr: }
09:24 PM rue_mohr: }
09:25 PM rue_mohr: ^^ hu?
09:25 PM BloodMoon: is winsize two ints?
09:25 PM BloodMoon: would be fine
09:26 PM BloodMoon: or is it defined in a standard header?
09:26 PM BloodMoon: likely th latter
09:26 PM aandrew: echo -e "\033[18t"
09:27 PM Tom_L: hmm
09:27 PM rue_mohr: http://paste.debian.net/1254723/
09:27 PM rue_mohr: terminal.c
09:27 PM rue_mohr: http://paste.debian.net/1254724/
09:27 PM rue_mohr: terminal.h
09:27 PM Tom_L: https://gist.github.com/fnky/458719343aabd01cfb17a3a4f7296797
09:27 PM BloodMoon: Spanks
09:28 PM rue_mohr: maybe
09:28 PM rue_mohr: it looks like an old version, but says its new
09:28 PM BloodMoon: ;)
09:30 PM Tom_L: wtf you escaping from?
09:30 PM rue_mohr: sanity
09:30 PM rue_mohr: the keycodes are an aweful mess
09:30 PM Tom_L: i'm afraid he did that ages ago
09:31 PM rue_mohr: see how many times key_home appears in the .h file?
09:31 PM rue_mohr: there are tonnes of random codes for the same key
09:31 PM rue_mohr: every time I opened up something new, there would be a new code
09:32 PM rue_mohr: case CTRL_KEY('l'): return CTRL_L; // I have no idea.
09:32 PM rue_mohr: it went beyond crazy
09:32 PM aandrew: the list I found was https://conemu.github.io/en/AnsiEscapeCodes.html#ANSI_sequences_processing_requirements and what I did was vt100: https://youtu.be/Ao9tBR33zv0
09:33 PM rue_mohr: there is a code for full 24 bit RGB colour definition eh?
09:34 PM rue_mohr: but that ^^ was the terminal return code for keystrokes
09:34 PM rue_mohr: good stuff in there
09:35 PM rue_mohr: I was developing it while writing an editor
09:36 PM rue_mohr: then I found out the editor I normally use (nedit) has rectangular selelct and text drag
09:36 PM rue_mohr: so the only feature I was left wanting is multiuser-concurrent editing
09:37 PM Tom_L: not too many do the rectangular select do they?
09:38 PM rue_mohr: no
09:38 PM rue_mohr: I can copy and drag rectangular slections too
09:38 PM Tom_L: i can't even remember the one i had that did now
09:38 PM rue_mohr: so building and dismantling columns is super easy
09:38 PM Tom_L: like a spreadsheet
09:39 PM Tom_L: only not
09:42 PM rue_mohr: huh, I could damn near use that same template as the disc sander for the pullies I need
09:42 PM rue_mohr: 1600rpm isn't too crazy
09:42 PM Tom_L: not even above average
09:44 PM Tom_L: much above 5 or 6k and you have to start considering balancing
09:44 PM Tom_L: beyond that, balancing is a requirement along with heat shrinking
09:47 PM rue_mohr: so, its just a matter of the small pulley on the motor being an engineering issue
09:49 PM rue_mohr: so, the motor driver would be a computer power supply rectifier and a half bridge
09:49 PM rue_mohr: is using a series wound motor, a rectifier on the field
09:50 PM rue_mohr: I have a 120 isolation transformer that i can use testing
09:51 PM rue_mohr: I have IGBTs that can handle the voltages and currents in their sleep
09:51 PM rue_mohr: I'v designed isolators for the gate drives
09:51 PM rue_mohr: I have a few chips that do gate driving with opto-isolator inputs
09:53 PM rue_mohr: if I back-to-back the leds in the isolators, I can call it protection against turning both halves on at the same time
09:54 PM rue_mohr: and now I know to use 15V for driving the IGBTs
09:56 PM rue_mohr: I do wish I had more focus
09:56 PM rue_mohr: I got the rings painted a bit more today
09:56 PM rue_mohr: just a few joints left
09:57 PM rue_mohr: and did yard cleanup, and took a whole truckload of wood to the wood-waste facility
09:57 PM rue_mohr: water tanks are almost out
09:57 PM rue_mohr: winter needs to come soon