*sigh* .. a laser i also wish for ;)
Someone mentioned a EMC workshop in the recent past, but I can't find any reference to the time and place.
hm.. i am thinking on adding more switches on this mill here for (eventually encoders), more switches (home) and eventually seperated limits, and thus i need more io. whats the recommended way to do this? add a second serial port via pci-card?
ah.. and in the end i need some for the reprap-extruder head ;)
How many in's and out's do you need? I'm certainly not in a position to recommend for the EMC group, but I like the Mesa Electronics boards for much expansion.
dunno exactly yet. currently i just have 3 end/home-switches (only one switch per axis) and no feedback from the steppers
so emc doesnt know what one does 'by hand'
i would like to add encoders on the 3 axis (means 2 inputs per axis) and eventually one switch per axis for homing.
the reprap extruder needs 2 lines per motor/heater, so its 4 outputs and one sensor (temperature of the head)
is the reprap useful?
Google Directions to fest #14 of 20: Slight right at I-40 E (signs for Needles/I-40) Passing through Arizona, New Mexico, Texas Entering Oklahoma - 1,215 mi
Optic as far as i can see.. we havent completed the extruder yet.
Optic but i know people who have one and it seems to be worth all troubles
it can make real stuff?
as far as i can see yes
limited material and precision of course, but one can always make it better and more precise of course ;)
uuuh.. i think i just found a interesting sensor vendor.. just quite expensive http://www.waycon.de/
JymmmEMC: 1215 sounds like too many miles.
cradek: No, that's only step 14 of 20, it's actually 1700 miles
cradek: Yeah, since everyone would be together, thought I'd bring out my POS and see if we could get it working.
are you coming then?
google says from LA to wichita KS is 1500
= 21 hours
cradek: 1700 miles x 2 @ 15MPG @ $2.25/gal == ~$510 in gas alone, unloaded.
two full days driving each way - it's possible but not much fun
cradek: But I'm in NorCal, need to drive down to LA then up to Vegas and across.
ah, thought you were in LA for some reason.
Oooops, not vegas, but still.
* cradek shudders at the thought of driving a car that gets 15 mpg highway
SF to LA is 400 miles about 7 hours
almost 4200 lbs
I definitely win with this location: 275 miles from home.
And it's EXACTLY in the middle of the country too
yeah, pretty close
it's a good location
[02:07:24] <JymmmEMC> http://maps.google.com/?q=2100+S.+West+Street+,Wichita,+KS+67213+&ie=UTF8&ll=37.655558,-97.649231&spn=55.104421,82.880859&t=h&z=4
Looks in the middle to me =)
Also, bad dates... my gf goes in for surgery at that time
heck. hope it goes well for her.
how much does a 'normal' encoder usually cost?
cradek: Yeah, only been waiting 2.5 years
roh: that's like asking how long a stick is. they go from $50ish on up to $huge
you could browse usdigital.com for a good idea of what kinds are available and they have their prices online.
hey all. will ubuntu work on an atom processor? 8.04 + emc2
cradek well.. what do you guys use? i found stuff which is up to 4keuro per axis
in every case when I've done a retrofit, the encoders came on the machine or motors I used, or were bought from usdigital in an appropriate form for mounting in the necessary place.
usdigital has a lot of shapes for different mounting schemes.
often if you have to fabricate a little something anyway, you can use their "kit" encoders for only a few dozen dollars each
besides 'more is better' .. how much resolution makes sense when one has 200 steps per rpm and 10microsteps? 2000? 4000?
"steps per rpm" makes no sense, and microsteps means you have stepper motors which don't need encoders anyway
so I'm at a loss to answer your question :-/
oh I bet you mean per rotation
but still, why are you putting encoders on steppers?
roh, there are some from DigiKey that are $30, and Mariss (of geckodrive fame) likes them
others have also had good luck with them
[02:22:50] <SWPadnos> http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=102-1307-ND
programmable resolution even, 16 settings from 48 to 2048 CPR
cool - programmable and with index
I don't know how well they last in an industrial envrionment, but Mariss has been using them for a while for drive developmnet
and that's apparently cycles per rev, not counts. you get 192-8192 counts
they can do 100/400 - maybe I'll use them for the jogwheels I'll make someday.
could be inexpensive enough to make it worthwhile, but I'm not sure
I sincerely doubt it
linux install question: error '/bin/modprobe/ abmornal exit'
can't seem to get past it. brand new disk, brand new atom processor board. new everything.
cradek the idea was to use the index for a more precise homing and the encoder in general to have a feedback of the real position, in case one moves the axis by hand
the bf20 doesnt replace the handwheels with steppers, the steppers just move them further out
ok, guys. is the emc iso 8.04 or 8.04.1 ???
Had lots of learning/fun with the mill the last five days ;)
ok, 8.04.2 works on the Intel D945GCLF. 8.04 does not install !!!!
1uS step speed =)
steve_stallings is now known as steves_logging
steves_logging is now known as steve_stallings
what's the difference between rt and rtai ?
rt is "soft" realtime, good enough for many things, possibly even medium performance servo systems, but not good enough for driving steppers; rtai is "hard" realtime
EMC does not yet have an implementation that runs on rt
rtai is usually reliable down to less than 20 uS intervals, rt is more typically several hundred uS
steve_stallings; thanks..been wordering about that
steve_stallings is now known as steves_logging
dammit i cant get my stepper to run smooth at low speeds :/
good evening.i want compile yemc , but i have the problem is possible a help?
with a higher iductance stepper motor the pwm cycle needed to hold a voltage in the coils should decrease right ?
lower inductance is better for steppers, because you want to minimize the time taken for the current to change.
cradek, ahh yes so inductance has to do with hax step rate also then right? :)
can only get my big steppers to about 2100uS step rate, while the small one could do all the way down to 1uS
yes very much so
but the bigger stepper works alot smoother at lower speeds then the little one :/
or not, it shakes like hell also :P
a big stepper will have much more low speed and holding power. a small stepper will go faster
he sure you are half stepping or micro stepping. do not ever full step.
i do high torque half stepping atm if everything is as it should
cradek, im writing my own controller using an AVR and a L298 :P
why not use L297?
cradek, cause i want to learn how it all works =)
and L297 do not use high torque half stepping and does not do anything more then half stepping :P
it uses the usual, full on, half on, full on, half on
what is high torque half stepping?
cradek, both coils always on at some degree
100%, 40% - 40%, 100% etc insted of 100%, 100% - 0%, 100%
oh, that sounds like microstepping
so much more uniform strenght in the steps then the usual half stepping
cradek, ye microstepping does the same thing but alot more current values :)
seems like my pwm code is working tho, the motor does not run hot at 12V like it did with my old only full step drivers :P
cradek: it's simple to see that with only 0% and 100% as winding currrents, the motor power is lower for 1-winding-on vs 2-windings-on
seems like that depends on how your chopper works
won't it keep the current the same, no matter how many windings it's going through?
l298 uses one sense resistor for each winding
oh ok, then it would make a big difference.
a ballast resistor unipolar setup would be another story
ye, im reading that into the ADc .. i put PWM on 100% until the winding hits a given value, then i turn the PWM to pwmForMaxCurrent * say 0.4 to get the pwm cycle, and i set that, and wait for the next step to occur
interesting, how fast is the adc?
cradek, dunno realy :) its an AVR adc so .. 100khz - 200khz or so
By default, the successive approximation circuitry requires an input clock frequency between 50
kHz and 200 kHz to get maximum resolution
or that might not be the speed :P
one conversion takes multiple adc clocks
15kHz, or smaller than the top step rate on a lot of stepper systems (about 600rpm at 1/8 stepping)
ohh set the prescaler of the ADC to 128 insted of 64 and got alot faster step times
all the way down to 1250uS insted of about 2kuS
but it still feels very slow :)
looking at the preconfigured stuff in emc, they got a billion faster step times then i can get :P
like gecko ... lightning fast
I love microcontrollers, but they're not very good for stuff like this
also quadrature counting
cradek,feels like its a tad to slow :)
not good for _________ ?
JymmmEMC: reading step/direction, reading quadrature, sensing analog stuff and responding very fast (running a chopper)
cradek: Really? I would think far better than paraport
yeah but that's a pretty low bar
im not realy expecting that much of this project more then learning how it all works =))
encoders spin much much faster than a parport or avr can poll them
that's why fpgas are universally used for the task
some AVR's are 10MHz, how can encoders go faster than that?
MrSunshine: I understand that for sure - learning the limitations of the design is an important part.
10MHz clock cycle, sure, but how fast can you read and decode quadrature and then do something smart with it?
While it's the CLK speed, that's 10 Million cycles per second.
and encoder puts out that much?
JymmmEMC, running mine at 10mhz now, aprently lost my 20mhz crystal
going 20 as soon as i find one
lets say the overhead is 5x, leaving 2 Million/s
but i can say one thing, my drivers performance kicks the other drivers i have asses a long way already :)
you're going to read and decode quadrature and do something with the result in 5 instructions?
not even John K could write it to work that fast :-)
wtf is a quadrature? :)
cradek: iirc, AVR can do 2 instructions per cycle.
MrSunshine a methid of encoding
time to hook this up to my 24V supply soon :)
its not even close to gettin ghot at 12V :)
ohh looks like my halfstepping doesnt work when i do it real slow :P
step by step that is :)
ohh wellt he duty cycles might not be a linear representation of the coil current :P
what are you mucking with?
i use pwm to set the current going throught the coils .. like a chopper but using pwm insted, but using just maxPwmCycle * 0.4 to get a 40% coil current doesnt seem to work very good :P
seems it goes to 0 in current
good evening.i want compile yemc , but i have the problem is possible a help?
thanks for help , my english is school version
but i have the problem with compiling the yemc.cc file.the terminal write: make:failed to remake makefile 'Makefile'. please hel me ?
i thing the problem is dependents the posemath.h and emcpos.h. is possible?
motioncontrol: maybe it's best if you say what you did so far?
simply replace xemc.cc with yemc.cc ? or something else?
thanks alex i have replease the xemc with yemc but not compile , have error.
alex i want control with emc 5 axis , with gui similar at xem.xemc control only 3 axis , but yemc 6 axis, but i have the problem for compile.you can help me please?
did you edit yemc.cc ?
yes i can edit
i have open in editor yemc
I think the remake makefile is because the dependencies for xemc are now wrong
did you try a make clean?
yes i have write make clean and after make , but compile stop not finish and not have the error.
simply exir at compile and blink the cursor terminal
alex you can prove the compile yemc.cc on your system?
I am starting now
alex the compile is ok or have exit and no complete compile?
lots and lots of errors
there was the problem with the remake makefile
but I fixed that by adding a couple includes
[20:08:27] <alex_joni> http://wiki.linuxcnc.org/cgi-bin/emcinfo.pl?FailedToRemakeMakefile
112 error lines now
it's a problem.you thing the error code or dependencies?
LOTS of things have changed from emc1 to emc2
yes i thing it the problem are the change emc1 at emc2. alex if possible correct the error is very good.
i don't have the know very good the c++
thanks for your patience alex
you are great
make: Entering directory `/home/pubuntu/emc2-test/src'
motioncontrol: it's compiling, but not quite working
alex excuse whath is the step for compile?
you have the code the yem.cc correct?
you can attach in pastebin
[20:36:27] <alex_joni> http://eneas.juve.ro/~juve/emc/yemc.cc
most of the changes I did (commenting out things), I used //FIXME-AJ:
or /* FIXME-AJ:
should be easy for you to see what I commented out
ok thanks alex now compile
ok alex the compile and the start the interface is ok.very thanks i are debt at you
motioncontrol: you need to remove the logging buttons, those don't do anything
i don't understand alex. i don't remove the button.
then forget it.. :)
alex thanks for your help . i want retrofit the maschine with 5 axis at my friends and i have proposed the use emc
and not siemens 840 d
if it works ok.. why not :)
the drive are analog and i use 2 card m5520
alex the next mouth i go in RO.i stay at Timiscioara.You stay at Timiscioara?
not sure, I have a trip to germany planned
i have my collega meccanico is Romania and work alla day at me.Can i speek you an my friend traslate if possible when you are free?
I'll see how free I'll be
ok alex.the next week i write you, if possible i and my friends go in Ro.Thanks for all your help is very utils.
good night at all.
good night all
skunkworks, It lives!!! no smoke leaked out so far.... running a 24vdc/20a motor
motor is getting warm, but the drive is cool
drat, I broke my .01" endmill. and I don't have a spare :( (past) time to order more, I guess
worst is, I have no idea why it broke. I looked over and saw that I wasn't milling any copper away..
in related news, I should learn to take others' advice more readily. having finally faced my table flat where I put the copper clad, I got very good results from a "vee" bit for trace isolation milling
somebody come over to my house and help me get my mill running