is it fossible to add some variables in to g code?
like this int lengtx=100 g0 xlengtx
like this: int length=100; g0 xlength
kwajstabo: yes, not quite like that
These are called "parameters" and they are referred to by number. e.g., #1=100 / g0 x#1
I thought learman had added support for variables. Is that only in head?
skunkworks: lerman added support for o-words
but that was ages ago
I think there was a wiki - let me look
yes there is an alternate syntax which actually has named variables, but it does not work in 2.2
er, it does not work in 2.1
that was in dec. 2006 :)
[12:49:12] <alex_joni> http://cia.vc/stats/author/lerman
[12:49:18] <skunkworks> http://wiki.linuxcnc.org/cgi-bin/emcinfo.pl?Named_Parameters
[12:50:13] <skunkworks> http://wiki.linuxcnc.org/cgi-bin/emcinfo.pl?AlternativeNamedParameterSyntax
oh some days I hate the wiki. "everything on this page is wrong; I left it here because of the bees" -- paraphrase
could be, the page doesn't make it clear
here is a nontrivial example which uses emc 2.1 numbered parameters: http://cvs.linuxcnc.org/cgi-bin/cvsweb.cgi/emc2/nc_files/useful-subroutines.ngc?rev=1.4;content-type=text%2Fplain;only_with_tag=RELEASE_2_1_6
anybody knows how can i write comments into g code (cant find this in pdf)?
(like this) ;)
kwajstabo: comments are inside '()'
kwajstabo: page 133 in my pdf has 13.5 Comments and Messages
it's Part III Using emc2, Chapter 13 Language Overview
cradek: is it "0805" or "1206" surface mount packages that you can fit a trace under? is the DRC smaller than 10/10 for you to do that?
I think it was 0805 but unfortunately I don't remember the details
it looks like 8/8 would fit under the capacitor package eagle calls "0805K" but 10/10 doesn't.
1206 works with 10/10
I may have made an 0805 package with slightly smaller pads
do quarters really conduct well enough to make this idea viable? http://www.makezine.com/blog/archive/2007/06/quick_hack_the_1_ctod_ada.html
* bill2or3 looks
I don't see why not.
heh mix the coin types and create some thermocouple junctions for increased power (not a lot)
it should work, but a C battery can't supply as much current as a D battery (nor for as long)
yay: "Subject: You Won eBay Item: Kuroda Ballscrew Leadscrew"
is kuroda a known brand?
the longer I work on this project, the more I just want to buy parts instead of make them.
Ball, no idea, but I'm sure it's better than what I'd have made in my garage.
which would have just been a Acme thread + delrin nut deal.
hehe, for sure
bill2or3: that's what we've been trying to tell most people for 2 years ;)
anonimasu, no argument here. I'd have more fun if I could make it myself, but my free time is scarce lately.
bill2or3: that's the thing, time vs cost..
at least until they make baby-sized safety glasses, I'm pretty much stuck in the house.
err congratulations :)
they make thoose safety glasses..
Hmmmmm, I wonder how my wife would feel about that.
jepler, is it possible to run the pluto for testing without a realtime kernel?
at least it's not possible without rewriting the driver to be a normal linux userspace program
ok, i'll use the other machine tomorrow
seems the amplification was 14x btw, maybe i put the wrong resistor in, i'll see tomorrow
well good night
yo ho ho
Petev: looks like you submitted a patch.. will try it tonight.
hey skunkworks, what be the haps?
ah - not much. pretty much relaxed this weekend.. It was nice
yeah, I don't know what happened. I had added some code to update the tune force dynamically during a tune when cradek was testing, but I guess I never copied the tested version back to my dev machine. I checked in some half baked version with a bug.
petev: cool :)
[17:37:43] <skunkworks> http://www.cnczone.com/forums/showthread.php?t=39532
it would be minor changes to the current driver to support it
probably just some defines
do you need hostmot-8?
you get 4 additional encoder channels with hostmot-4 and more IO, but only 4 PWM channels
That is not me - I am not real familiar with the mesa card. Just relaying the question.
I should probably tell him to post on the email list for a better responce
skunkworks: NOW we know your secret identity!
:) Na - samco on cnczone.
If we didn't then, we do now =)
I also have skunkworks registered but never use it.
I guarntee you don't want to know mine =)
WTH? QUAD processor??? http://newspaperads.mercurynews.com/ROP/ads.aspx?advid=32664&adid=4698778&subid=16666939&type=
jepler: could you kindly let me know the make and the model of the tiny servos you used for the pluto etch I see here: http://emergent.unpythonic.net/projects/01142347802
alex joni: could you modify the italian page "contattaci" in the italian version of linuxcnc.org and change "como usare la rete" and " como utilisare la rete" in "come utilizzare la rete", thanks
xemet: the were "maxon" brand motors. 2140.937 (24V, 6W, 3940RPM) with gearhead 110451 (6:1) and encoder 103945 (100 line). but I got them at a surplus place and don't know how or where to order more.
thanks, don't worry, I will search...I need at least a base to know wjat kind of servos I need
I would like to try the pluto
the kind of servos you need depend more on the servo amp than the pluto. For an l298-based servo amp, choose small motors (36V 2A or less for two servos per L298, 36V 4A or less for one servo per L298)
I need snall servos...I would like an amp like the one you build, with l298
the encoder is with the motor or you purchased it separately and added it to the motor?
the motor, gearhead, and encoder came together as a single unit
I'm searching in the maxon website
jepler: the first one you made was pancake steppers running off a 12vdc supply, right?
jepler: full stepping?
xemet: unfortunately I don't know anywhere online to get inexpensive, weak servo motors.
jepler: what's the max voltage I can use with your drive?
xemet: read the l298 datasheet for maximum ratings
xemet: this is the same motor I was using, but this guy is selling them for a lot more than I paid: http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=170122473014
[18:19:48] <jepler> http://www.st.com/stonline/products/literature/ds/1773.pdf
didnt threadmill motors work too?
I would buy tham for 29$...but they are in US and custom duties and taxes could be a lot
what's a threadmill motor?
I think some folks use them to run spindles because they have a nice speed control
I think les did tests with them for using them on the axes..
Hmmm, I wonder if they have enough torque to be used as a low speed spindle?
JymmmmEMC: servos dont really have a big problem with torque..
JymmmmEMC: they probably have a lot, since they're meant to move people at low speed
anonimasu: I mean tredmill motors
JymmmmEMC: yeah, but thoose should act similiar..
but dont take my word for it
That might be a nice retrofit for my machine (if I can find an swarf proof housing for em)
here's an inexpensive motor with encoder: http://www.hgrindustrialsurplus.com/search-products/product-detail.aspx?id=70-273-005
I have a feeling you can't drive it with an L298 though
jepler: was your pancake drive full stepping? half stepping ?
JymmmmEMC: half stepping
jepler: Is that due to a limitation of the design?
the stepper motor version was using a very simple unipolar design, just darlington transistors. full and half stepping were the only choices
ooh we need to send jmkasunich down to hgr to pick up this scara robot: http://www.hgrindustrialsurplus.com/search-products/product-detail.aspx?id=05-430-001
jepler: Ah, ok. Is there a parts list? The schematic doens't show the chips used
JymmmmEMC: ULN2803 if I recall correctly -- 8 darlington transistors plus freewheel diode in one DIP package
(the output from emc is winding activation, not step+direction)
jepler: Cool, I've always wanted to make something that simple with ordinary parts that are easily available.
jepler: winding... never heard of it.
jepler: is winding activation already in emc, and just needs the ini configured for it?
JymmmmEMC: A unipolar 5-wire stepper can be viewed as 4 windings (motor coils), with the common end of each winding hooked to V+. To step, simply ground the other ends in the right sequence
yes it's selected by a different step_type argument
at least 3 different ones, in fact: full-step one-winding, full-step two-winding, and half-step
of course at the time I was doing this in the first place, I was still trying to use emc1 .. to change from step+direction to this mode you had to change the source and recompile
after that I found that I couldn't find PID values that kept the steppers even vaguely on the commanded path (emc1 forced you to use PID even for steppers)
so I wrote my own terrible program to run the motors based on a subset of g-code
jepler: do you think those pancake motors have enough balls to turn a 10-32 threaded rod?
but with emc2 it is much easier
they are VERY weak motors and this kind of driver is the VERY WORST kind possible
jepler: Yeah, I understand. But if someone just wanted to paly around, they could do it for less than $50 total
the motors turn just fine when they're not loaded, or when turning an etch-a-sketch knob .. but I don't know how much more load they can take than that
I suspect some type of 2:1 pulley might help torque wise
and s/ipm/iph/ =)
that will also help with revolution, because many of the small motors are 7.5 degree instead of 1.2 degree.
jepler: do you remember what amp/voltage/ohms the motors you used were? Just so I have a ref when I hit surplus stores and look around.
I see 12V, and what looks like 36ohm, but the pic is fuzzy =)
JymmmmEMC: I ran them off 12V, which I think was the rated voltage. sure could be 36 ohm, it's not 3.6 ohm.
ok, cool. I'll have to remember the unipolar (I try to avoid that word much of the time =)
I think that 5 and 6 wire motors are unipolar
[18:50:44] <jepler> http://www.electronicsurplus.com/ccp71076-stepper-12vdc-48-step-rev-7-5-deg-step-82227-b82359-3350.htm
Is this for a etch-cnc?
I have some small geared stepper motors at home.
I'm not sure what JymmmmEMC has in mind, but I'm certainly answering questions about etchcnc
jepler: Just something someone could play around with, without diving head in like the rest of us.
Like maybe a scinece project a kid (or big 20yo+ kid) could do =)
$2/ea and 5000 available http://www.excesssolutions.com/cgi-bin/item/ES1766
I bet they'll give you a deal if you buy them all.
bill2or3: Yeah, they'll deal somewhat. Especially if I give the guy a hard time =)
I think they've been sitting on those motors for a few years.
lerneaen_hydra: cnc etch a sketch
lerneaen_hydra: No, jepler's http://axis.unpythonic.net/etchcnc
Jymmm: what are you thinking of using these tiny motors for?
Like maybe a scinece project a kid (or big 20yo+ kid) could do =)
Just curiosity, do EMI filters from mains really and an impact to cnc controller?
I had a friend who had unreliable encoder counting when he had spindle on-off using an SSR. adding some ferrites around the spindle power line cured it.
I meant like these kinds... http://www.excesssolutions.com/mas_assets/full/ES3918.jpg
I FINALLY got my hands on an 15A IEC power cord, then I took a closer look and the socket I have is only 5A (DOH!), but I was more curious than anything else, I know filtering couldn't hurt of course.
if you have any suspicion that your problems could be related to noise then choosing a part with EMI built in sounds like a good idea
jepler: It's only $6 for a 15A one (hard to find, even w/o the filtering) But I guess I never suspected that there would be that much EMI for some odd reason.
heh, EMI built in. "now featuring built in interference, the device interferes with itself" ;)
Hey, it's got the spec sheet up there for it too.
[20:07:31] <JymmmmEMC> http://www.excesssolutions.com/mas_assets/acrobat/ES3974.pdf
Nice, they have a lot of snap-on ferrites
Anyone need CAT6 STP 50M cables? lol
is CAT6 solid or stranded?
oh, it comes in both varietys
random note: it would be nice to have the up/down arrows bound to next/previous line in the file when you've already selected a line, so that pressing/holding down will step through the file rapidly and also show the selected line segments in the live plot
it would be a neat feature
JymmmmEMC: old powersupplies usually have them in..
skunkworks: Yeah, but not at 15A unfortunantly =)
[21:08:21] <jepler> http://www.makezine.com/blog/archive/2007/06/electric_bike_project.html
petev: It seems to work for me now.. But the numbers make for a very twitchy tune. (this is just a small servo with a fly-wheel attached.) May be outside what the z-n model can do.
petev: this is an at_pid with an effort of 10. Gives back P=570 I=23208 and D=3.5 http://www.electronicsam.com/images/KandT/servostart/ferrorat_pid.png
what's the method to delete *.bak and recurse that into sub dirs?
These numbers are actually similar to the numbers I get from the wikipedia formula
rm -R *.bak doesn't work.
petev: very cool though.. Nice work.
skunworks, ZN is known for a pretty twitchy tune
which tune mode did you use?
whatever the default was.
if you have a velocity loop in your drive, I think mode 1 is best
so you have a D value and no FF1?
ok - I will give it a try. I have a velocity moce
ff1 is 0
yeah, then use mode one which will give you P, I, FF1
you will have to set your scaling according to the man page for the FF1 value
the velocity loop takes care of D
that's the mode I use for my velocity mode drives and the tune is pretty good
oh - I think I am confused - I the whole loop is velocity.. I don't have tach feedback to the drives if that is what you mean
though I do have to run a 5KHz servo rate as my drives are pretty quick
huh, the PID is always a position loop in EMC
what is the command to your drives?
pretty simple here - emc -> pluto -> pwm -> h-bridge -> motor -> encoder -> emc
hmm, that is the setup cradek had and he had to tweak the numbers. If I recall, he had to add FF1 and FF2 and also adjust the numbers a bit from the auto-tune
I think he said FF2 was very touchy
he AT suggested much more I than he had, and this was good
my setup has a pretty large dead zone around zero - maybe +- 15 or 20% is pretty much dead
I wonder if that messes it up
I think P was pretty close, but there was some diff in D
can you still balance a servo
cradek, I also wonder how many poles a simple PID can compensate for
it might be plain difficult to tune some systems if there are too many corners
my hand tuning works really well, but it's touchy like you say
I think my system in pretty easy as the drive have a velocity loop and a torque loop
so I basically have 3 PIDs in the whole system
per axis that is
what's the linux command to tar something up, and recurse sub folders, even empty ones?
tar cvzf filename.tar.gz the-dir
maybe h too if you have sym links and you want what they point to
I'm gonna have to write that one down.
cradek, can that grab hidden files as well? like .htaccess files?
oh it did! sweet!
tar handles everything well except maybe hard links and files with holes
files that take less space on disk than their total size
wouldn't those be corrupt files?
many files have holes