#robotics Logs

Aug 25 2018

02:01 AM rue_shop4: _unreal_, heh, 5 wire motor for testing, but it turns out, its a 5 phase motor...
02:05 AM rue_shop4: WTF
02:08 AM mrdata: what
02:11 AM rue_shop4: 5 phase motor
02:12 AM rue_shop4: A--mmm--B ... C ... D ... E .... A
02:36 AM rue_shop4: wow, the voltage required for the steppers when running them in constant current mode is a LOT more than I thought
03:02 AM _unreal_: Star style?
07:25 AM weyland|yutani: you usually need a drver for them
07:25 AM weyland|yutani: driver
01:46 PM rue_shop4: no, its pentagon style
01:46 PM rue_shop4: 5 coils
01:47 PM SpeedEvil is now known as Guest78697
01:50 PM weyland|yutani: rue_shop4, can you point me to some resources about this pentagon style?
01:58 PM rue_shop3: its a motor you will almost never see
04:12 PM rue_shop3: _unreal_, so, 12V is not sufficient for running a 6V stepper at a descent speed
04:14 PM mumptai: maybe, but some will go higher
04:38 PM _unreal_: 6v stepper?
05:26 PM _unreal_ is now known as _unreal
06:46 PM rue_shop4: _unreal, steppers have all sorts of ratings, voltage is one of them
07:14 PM mumptai: they are usually driven by a driver operating as a current source
07:14 PM mumptai: the inductance dominates the slewrate at which the current can be canhged, and this limits the maximum step-rate
07:16 PM mumptai: higher voltages result in fast slew-rates, and lead to a higher maximum step-rate
07:23 PM rue_shop3: er, yea I know all that
07:24 PM rue_shop3: what I didn't know is that you dont get much speed running a 6V stepper on a 12V supply with a current mode driver
07:24 PM rue_shop3: I didn't build the driver for more than a 12V supply, so I'll have to rejig it a bit
07:24 PM rue_shop3: but its looking good so far
07:25 PM rue_shop3: ok I got the adapter board on the new coffee machine, I'll play with the esp8266 code later
07:25 PM mumptai: i actually don't know how the voltage spec is defined exactly
07:30 PM mumptai: probably the voltage at which the winding doesn't burn off if powered with DC
07:55 PM rue_shop3: sounds right
08:02 PM rue_shop4: http://ruemohr.org/~ircjunk/circuits/5wiredriver.jpg
08:35 PM mumptai: is it linear, or is clipping and phase-shifting enough for be chopping?
08:37 PM mumptai: s/for/to/
09:41 PM _unreal: So I have this board that came from some tool I believe it wad an automatic credit card writer believe it or not. that wrote the strip AND stamped info into the plastic..... but I gutted it and got a number of parts. one of the parts was an optical limit switch sensor board....
09:42 PM _unreal: 6 sensors, six POTS 6 LED's and a bunch of resistors. and it has an lm339 and lm393
09:42 PM _unreal: or 6 comparitors :)
09:42 PM _unreal: I'm going to use it on the new machine
09:43 PM _unreal: I just need to power it up and test it... I'm not 100% sure how it works?
09:43 PM _unreal: as in the output of it. I'm tracing down pins now
09:53 PM _unreal: ok I have it figured out now
10:04 PM _unreal: Just did a power test on my optical end stop switches. the board works great.
10:59 PM Jak_o_Shadows: What's the word for things to push bearings in?
11:04 PM Tom_L: press
11:04 PM Tom_L: hammer
11:04 PM Tom_L: sledge hammer :D
11:13 PM Jak_o_Shadows: aha.
11:14 PM Jak_o_Shadows: Nah,.m I just got a drill press, so wanted something maybe a bit better than the vise.
11:14 PM Jak_o_Shadows: I was thinking 3d printing little things to chuck into it
11:31 PM Tom_L: arbor press
11:31 PM Jak_o_Shadows: what's the name of the bits that go in an arbor press?
11:32 PM Jak_o_Shadows: Like, is it just a fixed size thingy?
11:32 PM Tom_L: https://www.amazon.com/Arbor-Press-1-Ton/dp/B00NOHYTPI
11:32 PM _unreal: https://drive.google.com/open?id=1k8US9cI7WMIMn3FHjpq8DcqPiSpv5e6k
11:32 PM _unreal: My optical limit switch board
11:33 PM Tom_L: wires are kinda short
11:33 PM _unreal: they will grow
11:34 PM Tom_L: shielded i hope
11:34 PM _unreal: not currently.
11:34 PM _unreal: I pulled it from some credit card embosing machine years ago
11:35 PM _unreal: lot of things had liner or rotory movements
11:35 PM _unreal: I've always wanted to use it
11:35 PM Tom_L: i used one on my first spindle encoder
11:35 PM _unreal: takes 5V.. and has 6 outputs high of 5v or 0v
11:36 PM Tom_L: http://tom-itx.no-ip.biz:81/~webpage/cnc/new_pulleys/new_pulley_mounted2.jpg
11:36 PM Tom_L: from a printer
11:36 PM _unreal: I'm going to use it for end stops. its also nice because it has pots tied into the comparitor. So I can fine tune the sense or try to limit any bounce
11:37 PM _unreal: most cnc software has soft debounce anyways
11:39 PM _unreal: how many index lines does that encoder have 50 60?
11:39 PM Tom_L: http://tom-itx.no-ip.biz:81/~webpage/cnc/new_pulleys/spindle_enc1.jpg
11:39 PM Tom_L: i since added that encoder instead
11:40 PM _unreal: more res?
11:40 PM Tom_L: 500 cpr iirc
11:40 PM Tom_L: so 2k quad?
11:41 PM Tom_L: the data sheet for it is on the site somewhere
11:41 PM Tom_L: http://tom-itx.no-ip.biz:81/~webpage/cnc/new_pulleys/Nemicon%20OME%20Encoder.pdf
11:41 PM Tom_L: off of some old medical equipment
11:43 PM _unreal: you know I'm not sure if I want to have +/- end limit switches on the new machine
11:43 PM _unreal: or just homes
11:44 PM Tom_L: i use my home switches for limits as well
11:44 PM Tom_L: i've got soft limits set up
11:44 PM Tom_L: i just used some cheap roller switches
11:45 PM Tom_L: http://tom-itx.no-ip.biz:81/~webpage/cnc/Mill_Steel/Assembly/X_Axis_limit1.jpg
11:45 PM _unreal: ya I have plenty of them laying around but I have this nice optical switch board so I figure F! it I should just use it