jmkasunich__ is now known as jmkasunich
dhc-8 Q-400 saga continues.... stray 'o' ring in the damping orifice... prevented downlock by hydraulic lock-up.... SAS maintenance will be ripped a new one i'm sure
who want to tho sharsies on an relatively excellent aircraft??? i could get a better deal on 3-4
high all anyone home>
skinnypuppy34: are you running without current limit?
zas that was the cat on the keyboard.
No I'm set at 3 A
I fixed some of my probs
geckos _BLOW_ when you dont have that
and you run your motors for too long
I got my rapid up to 90, reduced accel
I had mentioned the motors stalling earlier, apparently the trigger was bumping into the backlash too hard
Thanks again anonimaus , 5am nap time :o)
heh, that's a cute name "anonimaus"
alex_joni: my latest toy: http://arda.no-ip.org/crapmiller.jpeg
Hi, I have some questions that i hope someone can help me answer. 1. Is it possible to use EMC to controll a stepper motor connected directly to the printer port (using transistors to amplify the signals). 2. is there any way to calculate make EMC calculate the total velocity of a 2 axis machine eg. sqrt(velX^2+velY^2) and use the velocity to give signals to another pin (for example if i want 100 pulses / inch)
1 is possible, you just need to use a different stepgen step type
nr 1 is certainly possible
2 is also possible, but I don't understand what you want to be the output on the pin
Guest877: for 1. look at this: http://www.linuxcnc.org/docview/2.2/html//hal_rtcomps.html#sub:Stepgen-Step-Types
depending on your motor you probably want step type 5 I think
I will use it to control a laser, and I want to get the number of laser pulses per inch to be constant even if the speed change.
Guest877: then you need to calculate the speed
the sim/ configs have hooks to do that
Thanks, I'll try to find out how :), just wanted to know if it was possible before wasting alot of time.
[11:09:33] <alex_joni> http://cvs.linuxcnc.org/cvs/emc2/configs/common/core_sim.hal?rev=1.13;content-type=text%2Fplain
net XYvel hypot.0.out
you can then define anothe stepgen (laser-power)
and connect the XYvel to it
although now that I think of it freqgen is probably a better choice
(something like a velocity-mode stepgen)
thanks again :) now i just have to start building.
again sorry.. freqgen is the old name.. it's called pwmgen now :)
[11:11:10] <alex_joni> http://www.linuxcnc.org/docview/2.2/html//hal_rtcomps.html#sec:PWMgen
Vq^: what are you going to do with all that Z travel?
fenn: it should be possible to use it as a pluck robot for smaller machines
it's quite long for plasma cutting thought :)
btw, has anyone here used emc for plasmacutting?
not anyone here right now
Vq^: Dallur has
that wiki-page looked interesting...
[12:45:28] <Vq^> http://wiki.linuxcnc.org/cgi-bin/emcinfo.pl?Torch_Height_Control
well, if you build anything talk to dallur..
he's had lots of problems on the awy
on the other hand I ran my plasma without problems..
though I swapped it out for oxy because I need to cut really thick stuff
alex_joni: freqgen is now rolled into stepgen with ctrl_type=1; pwmgen is something else
make: Warning: File `depends/rtapi/rtai_ulapi.d' has modification time 3.1e+08 s in the future
hmm. maybe my date is set wrong (1998 Jan 1)
emc/task/emctaskmain.cc 2619: can't initialize motion
when running the latest TRUNK...
awallin_emc: sounds like a bogus compile
I suggest make clean, sudo ntpdate, and make
anonimasu: that's still ok for plasma :P
although a bit expensive
alex_joni: yeah, I'm doing make clean && make now
jepler: you're right.. I was still a bit asleep at the time :D
but for his purpose I think pwmgen might be better than stepgen
seems my config files are out of date:
emc/task/emctask.cc 312: interp_error: Coordinate system index parameter 5220 out of range
Coordinate system index parameter 5220 out of range
emc/task/emctaskmain.cc 2629: can't initialize interpreter
[13:51:56] <jepler> http://wiki.linuxcnc.org/cgi-bin/emcinfo.pl?UpdatingConfigurationsForDevelopmentVersions#var_file_changes
The .var file has been extended to require coordinate system offsets for U, V and W axes. Copy a fresh .var file. An incorrect var file leads to emc printing 'emc/task/emctask.cc 312: interp_error: Coordinate system index parameter 5220 out of range' at startup.
thanks, will try
is linkpp going to disappear soon?
it will be in the 2.2.x series but probably not 2.3.
JymmmEMC is now known as Red70sShow
Red70sShow is now known as Jymmm
anyone remember if it's possible to reverse the polarity of the PWM output from the m5i20?
doesn't the pin have an invert param?
there's an inverted pin for normal IO, but I can't find anything on the DAC/PWM
maybe negative gain?
use the dac -scale and -gain parameters ?
that will probably have the effect of inverting the "dir" pin of that dac
which may or may not be what you want..
hmm, so my motor stands still whenever I input -10 or +10 as the DAC command
setting a negative gain did not seem to work
and a small value or zero sets it moving?
at zero it jumps violently and then shuts down. maybe the servodrive goes into overcurrent
these are Jon Elsons servodrives
they have optoisolators for the PWM input
so could I just reverse the leads on the PWM
now I just automatically put GND to the '-' input and PWM to the '+' input, but maybe it works the other way around too?
I will have to try that.
if it's an optoisolator, seems like that has the effect of inverting
yep, jon describes it as an optocoupler http://pico-systems.com/pwm_pins.html
hm, it won't do anything if you put GND to the + input, since PWM doesn't swing below GND
wouldn't you put VCC to + and PWM to - then?
depending on jumper settings on the 5i20 board, either +3.3V or +5V is available at pin 49 of each connector
yes, thats more logical, since we want the LED to conduct
I have a separate -5V supply... will just take some time to wire
I guess the DIR input doesn't really matter, we can take care of polarity with encoder scale
+5V supply I meant
i don't think that drawing 3mA per signal will present a problem
now let's see...
yeah! it works. now I'll wire the other two axes the same
then I think I'll do a DAC vs. RPM test for all three motors
has anyone done something like a spectrum analyzer in HAL?
would be nice to drive the motors with a sine-wave command and look at the mechanical bandwidth
will be totally different now without load and then when the motors are on the machine ofcourse....
what's the easiest way to do an RPM measurement from an encoder counter value? ddt block probably?
but encoder counter usually has velocity estimation
(not sure about the 5i20 one..)
don't think the 5i20 has one (very un-canonical driver...)
ddt block is easiest, but it will suffer from quantization noise
run it in the slowest possible thread for best results, and/or run the output of the ddt through a low pass filter block
(I think we have one of those)
how 'bout using the index on the encoder? only 1 per revolution.
that will make it worse, not better
if you have a 5i20 or other hardware counter, you want to use the highest possible PPR and run the ddt block slowly to mimise the "noise" on the speed signal
smearing the noise out then
if you are counting in software with the most recent version of the HAL encoder module then you can use it's velocity output, which will be less noisy than ddt'ing the raw counts
example: 1000 rpm, 360 counts per rev, = 360,000 counts/minute = 6000 counts per second
with a ddt running every 1/1000 of a second, the result will be 6 counts
if you change from 1000 RPM to 1100, it will be 6.6 counts, so you'll get 6 sometimes and 7 sometimes
if you use a 6000 count per rev encoder, that gives you 6,000,000 counts per minute = 100,000 counts per second, = 100 counts every 1/1000 second
change to 1100 RPM and you get 110 counts every 1/100 second
ok, I will put it in a slow thread, and then scale the output to RPM
ddt outputs the change between ddt.N calls, right?
but it scales it so it is in units per second
in my first example, the frequency is 6000 counts per second, so the ddt output would be 6000
ah, ok. what is the ddt.time parameter?
.time parameters are how many clock cycles the function took the last time you ran it
more for debugging or performance analysis, not system configuration
ok. I'll put it in a 1s thread or something and try.
back to the example - at 1100 RPM, you have 6600 counts per second, but a ddt running at 1/1000 second will output either 6000 or 7000
this is for an RPM meter or something?
anyone worked with Jon Elsons PWM servodrives? I remember there was a special bootup sequence for charging some caps, but right now I'm getting a little erratic behaviour
you using his board to generate the PWM?
the ppmc driver generates the bootup pulses, other pwm generator drivers don't
nope, a m5i20
I don't remember the details of the bootup pulses, and don't have his pwm amps
ok, I'll ask him by email
[18:17:57] <jepler> http://www.bunniestudios.com/blog/?p=139
-- huh, I had never heard of a "16-point program" when it came to chinese counterfitting
"I don't think those typos are just because the person who copied this doesn't know how to type. I was talking to a friend in Hong Kong, and he said that knock-offs like this are regulated by what's called a "16-point program". The manufacturer must demonstrate 16 differences between his product and the original: this can include things like changing "Apple" to "Appls", or in another case, "Motorola" to "Mokorola". Each misspelling counts as one differen
Each misspelling counts as one difference. So as long as the manufacturer can point to a total of 16 differences, it is okay to sell."
now I did a nice DAC vs. RPM plot for my motor. anything else I could try while the motor is still on the table and not on the machine?
I guess I could try PID control now too. Are there any nice interactive PID tuning pyvcp panels out there??
I think you should make one
with sliders and analog-like meters and stuff
right :) do you think the command should come from a pyvcp panel or could that come from EMC?
do most people use step functions or a short linear move when tuning
awallin_emc: well, on commercial machines you sue step functions..
something like this: if I'm running EMC with a servo config, does EMC by default wire the PID parameters to values set in the ini file? could I not do that and have the PID gains set by a pyvcp panel?
I think the PID parameters aren't pins, so it's not trivial/possible to use pyvcp to tune them
you can tune live though - EMC sets the parameters to the ini settings, but it doesn't force them to stay that way
SWPadnos: I think I tried to change that, but maybe someone reversed my commit?:)
ok, it could be. I know siggen was changed to all pins, dunno about PID
ok, long day, need to clean up and go home - probably get to closed loop PID next week. bye.
they are still params
I'm out to do some chores as well
cool, i'm on a windows box but i find opera has an irc client :)
oh, it does.. never tried it :D
i've been looking at electric bike hub motors. they come with dc chopping controllers , like 36V/600W is common. maybe they can be used for spindle controls.
[21:57:16] <alex_joni> http://imagebin.org/11479
Hi guys, I'm looking for an easy way to convert vectors (svg) to gcode (something like truetype-tracer?). It has to run on my emc machine (Ubuntu 6.06). Any ideas?
[22:01:59] <Ziegler> http://wiki.linuxcnc.org/cgi-bin/emcinfo.pl?Cam
[22:04:02] <Ziegler> http://wiki.linuxcnc.org/cgi-bin/emcinfo.pl?AptProgrammingForEMC
might give you a leg up
Ziegler, I've tried ps2gc and it worked OK (except for a few errors with weird gcodes, missing feed, and some font outlines were rotated 90 degres). Thanks again.