cant do shite about some ov it
steve_stallings is now known as steves_logging
JymmmEMC is now known as red70sShow
red70sShow is now known as JymmmEMC
JymmmEMC is now known as Jymmmmm
maddash is now known as Yo_OY
Yo_OY is now known as o_O
o_O is now known as O_o
O_o is now known as Guest73104
Guest73104 is now known as o_-
argh all the good nicks are taken
o_-: try using morse code
I made a tool holder to put my ebay knurling tool on the HNC
but jeez, it's easy to get spoiled by usually working with aluminum
steel takes a lot more effort.
what kind of knurling tool? single wheel, dual wheel?
knurling takes quite a bit of push
I've never had much success on either of my light lathes
even on a heavy lathe, you won't have much success if you have a light workpiece
Gentlemen: I have seen true beauty today, in the form of a 1-bit DAC.
PDM + filter?
PWM + a capacity twisted together with a resistor
capacitor twisted with a resistor = a filter
yes, but oh-so-primitive
it was awesome watching the line on my scope dance from 0 to 3 V
oh, such beauty. why do people even bother with DAC's, anyway?
because sometimes 1-bit pwm isn't fast enough
what are the values of your R and C?
[03:16:30] <jmkasunich> http://jmkasunich.com/pics/hbm-vismach-ss1.png
the scissor type knurler always seemed more logical to me
what I've been working on ^^^
hm, good questoin
10k resistor, capacitor only says, "104K100V"
jmkasunich: nice CAD suite :P
maddash: = .1 uF
probably means 10 with 4 zeros after = 100000pf = 0.1uF
so, time constant is 10K * 0.1uF = 1mS
fine for motor control
not so good for say audio ;-)
jmkasunich: nice T slots!
in fact the whole thing is quite cool
I still want to put ways and a screw on the vertical axis, and make each major component a different color
did you take a bunch of measurements, or is the size approximate?
I'm just winging it
er, i get that "104K" ==> 100000, but wat about "100V"
when you add milling simulation do we get to see chips embedding themselves in the ways?
I'm mostly working from this pic: http://jmkasunich.com/pics/gilbert-with-part-2662.jpg
maddash: voltage rating
maddash: 100V is the voltage rating
so, >100V = big asplosm?
pico sized explosion
depends on how much current is available
put it across the AC line, and you'll get a bit of excitement
do ceramics tend to fail short or open?
with overvoltage they fail short
depending on the external circult, the resulting fault current might open it up
if you connect it across the AC line, something somewhere is gonna open
either the cap, your wires, or the fuse/breaker
the breaker hopefully
so 10^5 * 10^-7 = 10^-2; isn't that supposed to be 10mS time constant?
10K = 10^4
* maddash <=== stupid. 10K = 10^4, not 10^5
maddash: try the 'units' command
you had me doubting myself for a minute there - I didn't catch it right away ;-)
whoops, i'm in windows
there's a binary for windows too
so, tinier resistance and capacitance ==> faster stabilizing 1-bit DAC?
[03:26:41] <fenn> http://gnuwin32.sourceforge.net/packages/units.htm
if you are interested
does that make sense? if you remove the low pass filter altogether, wouldn't you have zero resistance/capacitance? so instantly stabilizing DAC?
no, you'd wind up with raw PWM
if the PWM duty cycle is 73%, and the voltages are 0 and 5V, that means the output is at 5V for 73% of the time, and 0V for 27% of the time
right, so, intuitively at least, more low-pass-filter characteristic (e.g., more resistance/capacitance) = more stabilizing voltages, right?
the filter attenuates the switching and gives you the average voltage, 0.73*5 = 3.65V
there is always some residual PWM - if you look closely enough, your "DC" output actually has a triangular ripple voltage on it
more filter = less ripple, but slower response
less filter = more ripple, but faster response
if you increase the PWM frequency, or go to PDM, you get less ripple for the same filter
(or you can use less filter to get faster response with the same ripple)
ah, no wonder --- I kept seeing wavy spikes and thought something was wrong with the probes/scope
do you have a two channel scope?
(and two probes)?
if so, put one probe on the raw PWM before the filter, and one on the filter
trigger the scope on the raw PWM
yep, I did that already before
that way you'll have a stable display, and you can see the relationship between the PWM and the ripple
no, I did see the ripple; I just didn't know why it was there.
substitute potentiometer for resistor to see the effect the filter has
huh? you mean swap the resistor for a pot?
10K pot, use the wiper and one end instead of the resistor
wouldn't that just squeeze the maximum voltage down?
use the wiper and one end to replace the two leads of the resistor, other end of the pot doesn;t go anywhere
more resistance = bigger IR drop, but your scope isnt drawing much current
you're not using it as a voltage divider, just a variable resistor
or just swap in different resistors
use 100K, you'll have tiny ripple, but slow response to changes
use 1K, and you'll have faster response, but more ripple
ditto for changing the capacitance, b/c the equation tau = C R
in fact it is easier and less likely to have side effects to just change the C instead of the R
for example, if you wanted a 1000 times smaller time constant, you could change the R from 10K to 10 ohms, or you could change the C from 0.1uF to 100pF
10 ohms is a rather small R - the C will be almost directly across the PWM output and will probably load it down
in fact, the internal resistance of whatever is driving the PWM output is probably more than 10 ohms, could be 100 or more
bedtime here, goodnight folks
jmkasunich: quick, what camera do you use?
holy crap, $750+
cheaper than equivalents from Nikon or Canon
is there any hal comp to make mux2_bit operation ?
can you write more clear ?
anyone know a good setting for ferror and min_ferror for emc2?
do you know a good speed setting for my car?
to the floor ?
piasdom: can't answer without more info
I assume it's a servo machine?
thought i was asking a stupid q
no, the question is ok, but it's not a generic answer
ok.. what's a step size on your machine?
x 8" y 4" z4"
not the table size..
the distance it moves at one step
step angle ? 1.8 degrees
ok, that means 200 steps for a motor rotation
20 TPI screws? (that is common afaik on sherline)
ok, next we need microstepping..
that depends on the driver that is driving the motors
I think it's settable at the driver
is that 16000/step/inch ?
that is SCALE
so at every step your machine moves 1/16000 "
ferror is how far the machine can get behind the commanded position
i see 800 setp per rev
800 step / rev = 200 step/rev motor * 4 microsteps
going to look for microstep brb
if your SCALE is 16000, then microsteps is 4
if you have 800 steps/rev then microsteps is 4
16000 = 200 * 4 * 20
SCALE = steps/rev at the motor * microsteps * tpi
I would probably try:
FERROR = 0.050
MIN_FERROR = 0.010
but it's up to you if 0.05" is good enough :)
you can try lower values, but probably need to finetune vel/acc
making it smaller will get better tol. ?
if your machine can't get that accuracy, emc2 will error out
well, i get linear error
can you type the exact error?
1 - linear move on line 5 would exceed limits
1 - linear move on line 5 would exceed limits
line 5 ----> g81 f4 x.25 y.1 r.05 z-.03
Perhaps your software limits are set wrong ?
in my ini ?
or you're not homed, or you have an offset you don't expect
i 0'ed all before i start
start with jogging. after you home the machine, you should be able to jog each axis its full distance and no further
if this test fails, you need to work on homing and/or soft limit settings
i can run a example the came with emc
i can't run in manual to my limits
my limits are x0 to 8" y0 to 4" z0 to 4"
Z should probably be 0 to -4 so you can home at the top of travel instead of the bottom
piasdom: the command you showed has "z-.03", but you said your minimum z limit was 0.
after you change that, restart emc, jog X all the way to the left, home it. Jog Y all the way to the back, home it. Jog Z all the way up, home it. Then try jogging all your axes to their limits again.
err, I was unclear about X,Y -- move the tool to the near left corner of the table
and up all the way
this is your home position
don't crash it ;)
(he has no limit switches,..)
yeah I'm assuming no switches
bah, my hand is all messed up...
soft limits will protect him, all he has to do is home it in the right position
struck it against the exhaust of my scooter while i was putting the spark plug cable back in it's place...
cradek: if you restart EMC? how can the soft limits protect him?
jepler: thats what I said.
fragalot: after homing, soft limits are in effect
cradek: Aye, AFTER :p which means he has enough time to crash it :d
sure, that's the fun of homing
half an hour till class starts..
but z and y are backwards :)
piasdom: so,.. invert the dir pin
but i can fix that.
thank to all of you
two ways of reversing direction of travel on steppers: negate SCALE (ini), or invert direction pin (hal)
some controllers (mine) have that "invert" feat. built-in, or you can do it in EMC.
i do have the invert
either is the same /
either you invert, or you don't... but both ways jepler said can work.
the effect should be the same
i got my upgrade and my machine THANKS
somebody here is watching the simpsons... with the volume all the way open >.>
and it's got the long intro..
hehe, I think uni is looking into getting the classrooms repainted,... They are walking arround with colorschemes,..
[13:37:04] <skunworks> http://woodgears.ca/index.html
*sights* UPS is takeing forever.
what have you ordered?
just some stuff from Sherline, I currently live in Sweden.
[13:54:56] <cradek> http://www.coolweldstudios.com/jeffpics/frankjoymike.jpg
thats very nice
cradek: have you done that yourself?
no, just saw the picture somewhere.
is there a trick to get one axis to go on indefinitely (i've disconnected motor shaft from lead screw)
can it run for a seriously long time then?
mr_boo: is this just for testing?
jepler: i need to refurbish the motor shaft
if you just want to keep a motor turning one direction at a set speed without limit, you can do it in hal without emc
load stepgen in velocity mode, and set its velocity input as desired
is hal a separate application?
HAL is the low level driver and realtime system that EMC uses
hal is the hardware abstraction layer that emc uses
you can use it directly with 'halrun', a commandline program
prolly too advanced for me
if it's a DC servo you can just attach a power supply to it directly
its a stepper
some reading material on HAL http://www.linuxcnc.org/docview/html//hal_tutorial.html
untested (I don't have any bare motors handy :-P) http://emergent.unpy.net/files/sandbox/turn.hal
save that to 'turn.hal', then in a terminal in the directory where you downloaded it, you can 'halrun -I turn.hal'
your motor should start turning at 200 steps per second (30RPM if half-stepping)
it should stop if you type 'quit'
you could vary the speed by typing 'setp stepgen.0.velocity-cmd <number>'
it will ramp the speed when you change it, according to the 'maxaccel' value
.. assuming I got all the details right, anyway
jepler: after I test this I'm stealing your code for the manual :)
if your stepper boards have an enable pin, you might need to 'setp parport.0.pin-??-out 1' for that pin
:'( uC class and i forgot my devboard at home.
Owell, slacking time!
fragalot: at how many milliHz can you run AVR code in your head?
so could you do a halrun -f turn.hal do you still need the -l?
I bet I get about 100mHz
BigJohnT: -I (capital I for interactive)
BigJohnT: if you used -f it would exit immediately after running the lines in the file, so it would not step very far
just reading the man page and wondering out loud
I guess I should say "capital i" to best clear up the font confusion)
the capital letter than sounds like "eye" or "aye"
what letter is that? :)
dunno some sea faring gibbersh
aye, me heartiew
pirate looks so much better without typs
I can't even spell typo today
BigJohnT: "halrun -I -f turn.hal" would be the same as "halrun -I turn.hal". To make things simpler, if you give a .hal file to halrun it adds the -f for you.
ok thanks jepler
jepler: in AVR code? ... approximately 0. :p
how about with paper?
[14:39:29] <jepler> http://arduino.cc/en/uploads/Main/arduino-duemilanove-schematic.pdf
<-- hm, I don't quite follow this schematic. the part of the circuit at the top involving IC5 and T1 is for automatically switching from external to usb power. why bother wiring IC5B in buffer configuration? why not use a single op-amp instead?
"because it's there" ?
you'd think that there would be some filtering or something, to make it look useful
instead of grounding the inputs maybe..
worked better layout wize?
well, short wires should rarely be easier to route than no wires
could someone write a hal script that runs the X-axis motor at a constant speed please?
i've tried to walk through the tutorial but it was seriously complicated
did you not notice that jepler wrote one for you already?
jepler did that for you one hour ago
it may not work perfectly, but you should be able to figure out how to fix it if it doesn't
there it is
he even wrote a guide how to run it
is there a line i could add in the script to see that the program actually is trying to do anything?
right now i just get into the prompt when using 'halrun'
once you're at the halcmd prompt, you can type HAL commands to look at things
so you could do things like "loadusr halscope"
or loadusr halmeter
i've tried to change pins and no motor ever moves
they're dead like doornails
if the motor can move under EMC control, then you should look at the EMC setup and change the file jepler made to use the same pins
of course we don't know how you have your hardware connected, so you'll have to fix that
the pin numbering in his example was arbitary
could be, I haven't looked at it
now it works
many thanks SWPadnos and jepler
sure - have fun with it
You're welcome. *walks awya with the glory*
no, sorry. I'm reserving the glory for jepler. he did all the work
mr_boo: why not just open up the stepconf wizard and test the axis with the test button?
Can I atleast touch it once,
SWPadnos: how do i change the rotation direction?
SWPadnos: i noticed i wasn't allowed to write to that pin
set the velocity to a negative number
velociraptors.... cute buggers
fragalot: to bad they are to thick to fit in most laptops :P
[15:57:30] <skunworks> http://woodgears.ca/eyeball/index.html
2.63 is the best I have done
many thanks for your support
I have a made a PCI card with fpga, and i wanted to do a driver for it for emc2. I have seen that there is multiple drivers for a card mesa5i20, but don't know which is the current one
the hostmot2 drivers are the newest
I see m5i20,mesa_5i2x and hostmot2
mesa_5i2x is a branch of development that has mostly stalled (we don't know if we'll pick it up again)
i see that hostmot2 is a lot heavier than the others
yes, it supports several cards on different buses (PCI and parport)
the m5i20 driver is probably the simplest if you're looking to support a relatively simple I/O and encoder/step generator/PWM kind of thing
my pci card only has PWM generators, and the encoder counters
and GPIO probably
the hostmot2 driver supports enabling/disabling of functions, using the pins as GPIO if you've disabled something like a stepgen or encoder counter
i have seen the hostmot2 code, and it seems complex
if you're doing a relatively simple memory-mapped or I/O-mapped interface, then the m5i20 driver is probably the best to start with
ok, the stepgen is needed?
* BigJohnT is glad SWPadnos jumped in to answer that question :)
hostmot2 is more complex because it supports several cards and many features on the FPGA
my cnc machine goes with servos
not if you don't plan to support steppers
then it's not needed
ok alex :D
i will go with m5i20
what are you putting inside the fpga?
i'm putting the pwm generators, the counters and gpio for global purpose
i don't know if anything like speed calc. or acceleration hardware calculation will be needed for emc2
one recommendation: group the registers as closely as possible, and also try to make all the information available with as few register reads/writes as possible
my pwm generator are for the 4 MOSFETS of the Hbridge
some PCI chipsets are amazingly dumb (including a specific one from Intel which I don't remember at the moment), and access wasn't much faster than a parallel port with it
except that it was 32 bits at a time instead of 8
ok, my pci hardware in the card is in the FPGA itself
i see that the mesa card has a dedicated chip
not the chipset
SWPadnos was talking about the north/southbridge on the motherboard
ok, I understand
this particular chipset didn't do any write or read combining, so it would do an entire PCI setup /teardown for each read or write
I think it was only able to do something like 2 or 3 operations per microsecond
close to parallel port speed
I thought of reading all the registers in a bulk pci read, so it would be faster
but i have not implemented it yet
so the direction address is only tranferred once in the pci bus
yes, a bulk read and/or write would be good, but there may be more setup than it's worth
you should only be reading and writing <8 registers or so
ok, i'm going to study the emc2 code, is anything worth to mention before reading it? any diagram available that could help me to take the big picture? i'm a bit lost
I don't think there is any good high level documentation for that
cncman: try the documentation links at www.linuxcnc.org
i have read already the developers manual
ok, i have setup the opengrok with emc, it's time to study
the basic structure is that there's a C Struct which mimics the memory map of the FPGA, and access is done through pointers to the card base address
[17:35:26] <alex_joni> http://www.linuxcnc.org/content/view/42/13/lang,en/
oh, the EMC2 code - here I am thinking of the Mesa driver still :)
SWPadnos: are you the author of the mesa driver?
Pete Vavaroutsos did most of it. I may have done a modification or something
I know about the hardware because I helped out with the 5i2x driver design, and I've done another product with a different one of their FPGA cards (the 5i22)
and are you using the hostmot2 driver or the m5i20 one?
nope. it's custom :)
I'm not sure what I'll use when I eventually put my machine together
I may resurrect the 5i2x driver, but I'm not sure
mmm, a pity that the firmware code is in vhdl, i'm better with verilog
I could do a hostmot2 clone in my card and use the driver almost without modifications
feel free to write a translation :)
I think that wouldn't be very sporting of you
ok, if i do it, i will post it here for anyone uploading it in the cvs
Mesa sells hardware, and has GPL'ed a lot of source code - making competing hardware that uses the fruits of that seems icky to me (though it's still within your rights)
YEA my FREE Gecko drive arrived and it only cost me postage out
what fpga chip did you use?
BigJohnT: hate you :P
BigJohnT, how'd you manage that?
I sent my broken drive in and they repaired it and sent it back :)
ah, not that free then :)
SWPadnos: no, i'm not doing competing hardware. The machine is for my use.
no it cost me $5 to ship it to them
heh - I'll bet a Mesa card would have been cheaper then, if you count your time at anything above $0.27/hour ;)
SWPadnos: but it wouldn't be so funny ;)
I only get 10 cents per hour :)
you do documentation though ;)
at least on payday I have some sense...
(hmm. hard to type a cymbal sound)
i want the cnc to do the drilling of the pcboards, has anyone try a cnc machine with a laser?
there are a couple of people using lasers with emc2
i want to drill fr4 boards without copper clad
good night all
hmmm. is it insensitive to say "I kill me" after a joke in an email to someone who had a fiancee commit suicide?
I don't know, but I find your question funny and slightly disturbing at the same time.
I guess I should have answered that question before hitting "send"
at least the suicide was a few years ago
i think a better question is think about the crowd you're asking
well, I'm sure it'll be fine
she's got a similar sense of humor as I do
err - please correct for tense and that kind of thing :)
I think that would be wrong..
well, shit happens
anyone know why the words in my file dropdown menu are just lines(in mini)
and before i head home, i just want to thank all that helped me get this comp and mill going.
i really appreciate it thanks again