got a question about emc2 cvs head version
ask away. The topic of this channel should say - 'don't ask to ask a question - just ask it' :) Some one will hopefully have a answer.
where is the G50 adaptive feedrate code, when i put it in my ini file, it bombs out with unknown g code.....
mdynac: I think a new code for that feature may have been chosen. let me see if I can find what it is.
it *looks* like it is now m52 p1 to enable and m52 p0 to disable, but I am not able to test that right now
is only present in the cvs head version?
can i some how incorporate it into emc 204?
not easily, no
well is the cvs head version stable?
at this time, it's not getting many new experimental things added to it. but it hasn't had as much testing as the stable version 2.0.4.
if you do decide to try it out, please let us know about any problems you encounter
i sure will, i am going to test it tomorrow, but my machine has no internet connection.....can i get a tarball of the cvs head?
is that the web interface to cvs?
at the bottom of this page, there is a link that says "download this directory in tarball"; click it and save to disk
[01:57:31] <jepler> http://cvs.linuxcnc.org/cvs/emc2/
kewl thx, now do i put the M51 P1 in the RS274NGC_STARTUP_CODE=M51 P1?
yes, that should enable it by default
the machine at the moment is working great as a giant etch-a-sketch, the axis are steady and accurate, i have eliminated the following errors and the servos are tight...so now onto the adaptive interface....
the axis interface is awesome, it even debugs g code, i love it!!!
how do I figure out if qcad is "free as in speech" or just "free as in beer"?
the qcad website says it has professional and community editions
help->about says professional, but it was downloaded from the ubuntu universe repo
i need to find a linux cad pgm as well
still have visio on my windows box
thats not cad
* jmkasunich hates visio
I am a very satisified long term user of easycad (commercial) on doze
the next version of easycad is supposed to be multi-platform with a linux version
but not out yet
as far as free CAD, there's qcad - but I find it pretty lame compared to easycad, and wouldn't want to do any serious work with it
03jmkasunich 07HEAD * 10emc2/docs/src/code/ (5 files): added source (.dxf) files for a couple documentation drawings, added some notes about how to generate postscript from the source, and modified the lyx to use the new postscript files.
03jmkasunich 07HEAD * 10emc2/docs/src/README: added source (.dxf) files for a couple documentation drawings, added some notes about how to generate postscript from the source, and modified the lyx to use the new postscript files.
jmkasunich: on doze I recently found and used alibre
it has a _very_ nice free version
it can do 2D drawings and 3D solid modeling
Hello Guys, is anyone using a usb driver for controlling Stepper motors
tray: not to my knowledge but the other guys will know better once they wake up
tray: I know for example the Gecko USB driver essentially has an embedded controller in the usb device
Dallur: Thanks. My computer I was going to drive my steppers with has a parallel port but since I building my machine, thought that I'd try to future-proof it as much as possible.
Dallur: What do you mean "morning" its evening here. Have you had much experience setting up emc, hals etc??
I have just installed EMC2 and have been playing around with the etch 2 axis servo this was just to test some pittman 500cpr servos I have. I am looking at either building my own controller with maybe a pic chip or purchasing something like the gecko servo drives. I have used the first version of EMC with the stepper mod but I remember something called freqmod and this is where I.m a little...
...confused. With EMC2 what module(s) could/should I use with these drives step/dir and what other options are there i.e. how do the different modules act and in what situations would one use one particular method as opposed to another. For example it appears to me that the step/dir method of driving a servo controller is not a true closed loop back to EMC2 but only closed to the controller...
...what system would be used for a complete closed loop back to EMC2? Thanks!
im a bit slow btw, im at work and just taking sneak peaks at irc
No problem Dallur ... don't get in trouble for this ... ;-)
if you are running steppers I recommend using the stepper mod for sure
I won't get into trouble (self employed)
Me too .... Unix (solaris / linux)
:D I do mostly consulting on software projects, most of my time is spent on working with developers which don't know any IT and telling them why this and that is important
oooch .... lol
stepgen has built in freqgen and everything pre-wired, and I think it is more efficient
so you can build your own stepper config with freqgen but there really is no point, it's way better to use the stepper stuff
stepgen is that a controller product?
err sorry misunderstood question (should have read it more carefully)
The reason I was asking is that I have some pittman servos with 500cpr encoder that I would like to use
thought you were talking about hal internal stuff
I have not experience with using servos so ... not much advice I can give there
No its more broader than that
the question really is "should I drive servos as servos or use stepper emulation servo controllers"
hopefully someone with servo experience can give you some good advice on that
For example some servo controller ie Gecko have there own internal PID control. However EMC2 has PID filters so I am confused as to what situation and what products would use EMC2's PID filters and the benifit of this as opposed as using stepper emulation servo controllers.
No problem thanks for your time Dallur. It's good to see Robin
Robin_sz is still hanging around here. Is Jon Elson still involved with the EMC2 project ... They were both very helpfull a couple of years ago with my emc.ini file setup....
yup, he is
as far as I know
Good to know.... Thanks again for your help Dallur I'll let you get back to work .... Mmmm I better do the same ;-)
Paragon36: still around?
the basic advice is this: if you can afford to drive servos as servos then do it. if not driving them as steppers might help
driving them as servos usually means a special piece of hardware (range 300-1000$) which controls the analog servos and takes feedback from the encoders.
you can also do it like the etch-a-sketch, but that is intended as a (from several aspects) limited hack
Sorry Just got back to my desk ... hello
What hardware would be required to drive the servo as a servo say for a 3 axis machine?
there are several
the wiki.linuxcnc.org has a list
[13:42:55] <alex_joni> http://wiki.linuxcnc.org/cgi-bin/emcinfo.pl?EMC2_Supported_Hardware
Thanks for the info.... I have been doing a little more research since my last post.... What I am thinking about is programming a pic microchip to accept step/dir from EMC2 the PIC would take care of PID and send PWM for example to an L298 enable pin it would also sent hi - low TTL signals to its input1 and input2 for direction/polarity control the pic would also receive TTL encoder or...
...single ended signals from the motor encoders these encoder signals would then be forwarded to EMC2 paralel port so one could also use EMC2 PID or DRO funtions. How does this sound would this be a sound impementation? Oh additionaly the PIC could also multiply the step signals from EMC to produce a smoother drive signal to the H-bridge.
Paragon36: a few people have driven servos with software-generated PWM and software quadrature counting -- me, cradek, and skunkworks. cradek's is probably the best example, a finished lathe conversion.
someone else here, I think LawrenceG, has PIC software to do what you describe. Unfortunately I don't know the URL for his work offhand.
ah, here it is: http://members.shaw.ca/swstuff/dspic-servo.html
When you say software driven are we talking about step / dir to say a gecko drive or as in the etch example that comes with EMC2 live cd? Thanks for the link Jepler
Paragon36: Instead of outputting a step+direction signal, the PC outputs a signal that directly drives an H-bridge like L298. Yes, like the etch-servo sample configuration.
this has some disadvantages (the "PWM" waveform is not as high precision or frequency as one you will generate with a microcontroller; the number of quadrature steps that can be counted is similarly much lower) but the big advantage is that emc2 knows the exact position of the motors at all times, so you can do things like deactivate the servo amplifiers and use handwheels without losing position.
I was under the impression that this was limited to 2 axis due to the para port pin limitation. Additionaly is there not a limited pulse train in/out due to para limitation?
Oooops I think you just ansered my last question.... is it limited to 2 axis of motion though?
if your parport is capable of the "x" mode (only available in the development version of emc2) then there is also an 8-output/9-input configuration available. That's enough to drive 3 axes and a spindle, and get quadrature back for each axis.
but at this point we don't know how many parports can use this mode
In some parallel ports, the control group pins are open collectors, which may also be driven low by an external gate. On a board with open collector control pins, the ``x'' mode allows a more flexible mode with 8 dedicated outputs, 5 dedicated inputs, and 4 open collector pins. In other parallel ports, the control group has push-pull drivers and cannot be used as an input." -- http://www.linuxcnc.org/docs/html/hal/drivers/drivers.html
PCI parport cards are often available for less than $30 and offer another way to support more than 2 axes
and with proper level-shifting, you can also use "serport" (only available in the development version of emc2) to get 4 digital outputs and 3 digital inputs per rs232 serial port. http://www.linuxcnc.org/docs/html/man/man9/serport.9.html
if you don't want to do any of this "weird stuff", then dspic-servo is probably a good alternative
I see! It would be nice to be able to run three axis. I was playing with the etch using a pittman 24v 500cpr servo and was very impressed at the ease of getting it to turn and count. although I think I need to set it up correctly. I set the count 2000 / 0 for 1mm per rev of motor but the motor drifted off if say commanding 50mm I think this could be down to the error as Im using the default...
...PID setting would you agree Jepler?
I played with a couple of parallel ports and I highly recommend using pci parports, many modern motherboards have crappy parports, I have seen motherboards where high state was only 3.7v under no load !
Yeah I can see how that could cause all sorts of debugging problems ... > 3.7 .. :-(
Paragon36: I don't remember for sure, but I think that the etch-servo sample configuration has pretty big values for following error and deadband
my lathe setup uses "x mode"
cradek_ is now known as cradek
Have been having an interesting conversation with jepler regarding what we discussed earlier. :-)
Just looking at the dsPic servo link ....
has he convinced you that step-dir to servo is a bad setup?
after using a true closed loop machine I don't see why people tolerate (and build anew) "half-servo" systems with no real feedback
I can see the limitation inherent in that setup. I do like the etch-servo route but it appears that also has some limitations or at least I initialy thought it had ie limited to 2 axis
and para port pulse stream limitations
its limitation is mostly the limitations of software counting and software pwm generation
but you can use external hardware for those things
I was just about to ask you what hardware one could use?
etch-servo was done as a fun project to show the power of HAL, and I based my lathe on it with great success, but I'm not sure it's appropriate for a big machine
I'm not an expert on the hardware ... I'm sure each has benefits and limitations
any of the options with analog/pwm outputs and quadrature counting are going to work well
I think etch-servo is great I got my servo turning in 10 minutes ... :-) I too would only be using small servo's for the home workshop
I know the m5i20 and ppmc family have active support from their developers
(I know that from seeing it on the lists - I don't have either of these setups)
But is there still not a limitation with the conectivity back to EMC2 ie its limitation for pulse train counting
for the encoder ....
no, they cout the quadrature in hardware, and emc2 just reads the count whenever it wants
those setups can count very fast (in the MHz)
Oh so emc reads a say a byte with the position information as opposed to reading the pulse train? is this sent via the para or serial port?
ppmc uses EPP parallel port, others are PCI cards
STG is an ISA card (not recommended anymore)
I think there are a few more that are PCI
OK so they are internal ... > Quite expensive for the home buget setup i would think
everyone has a different price/performance tradeoff
But if the capability is there for EMC to read position information in a byte stream for instance a pic chip could send that to EMC I guess | Horses for courses ....
for a few hundred you can get a xylotex stepper driver, power supply, and motors
you might be surprised how slow PICs are compared to your encoder's output
if you're not going to use an FPGA it might be best to just use emc2's counting - you might do a bit better with a PIC but you'd add a lot of complexity
I currently have a Denford StarMill which uses L297 / L298 combo which Ive hot wired to EMC one thing I noticed I could not get the steppers to move as smoothly as I can when using it propriety DOS program tht connects to it via serial .... I think it could be as I was using stepper mod on an old pentium pro 200 (EMC1)
steppermod was extremely primitive and emc2 is a whole different world
as far as software counting and pwm goes, on my lathe I have about .002mm resolution and 1500mm/min rapids, that's about the range you can expect if you choose your encoder resolutions correctly
I am going to try it again with EMC2.... The reason I want to go down the servo route is that I purchased 10 pittman servos for like $12 inc shipping to UK pluss its a new concept for me to learn that keeps the grey matter active ;-)
that's why I used servos for my lathe too. for fun, and because I had them (jmkasunich gave them to me)
Nice ..... Dam 1500mm that great I mean 1.5 meter that could do some dammage! But thats plenty fast enough for what I have in mind. CO2 Laser cutter is one project and it would only require 2 axis so could be a good start.
yeah the rapids are pretty fast
I could have traded more resolution (go down to .01 or .005mm) for faster rapids, but the travel is so short it's silly
I mentioned earlier that i hooked up one of the small servos to the para port and using etch-servo with the default PID setting and the .ini INPUT set to 2000 / 0 which I think equals 1mm per rev of motor with 500cpr (2000) (is this correct?) if I move to say 50mm the motor does not stop at its starting point as I would expect it to but rather overshoout a little is this due to the...
my little lathe's X axis with keyboard and cat hair
...default pid setting and error compensation
Im look now ...
does it overshoot and then come back?
Nice those are very similar to the pittman servos I have .... I think they may even be Pittman servos.
cool, they worked nicely for me
bad pid tuning can look like a lot of things - sloppy stops (overshoot, creeping) are all possible
Answer :- No it does not come back. but when i then command it back to 0mm it comes back dead on where it started!
oh maybe it's the scale specified wrong then?
maybe your encoders are 512, not 500
no I guess that would make it stop short
to debug, use halmeter to watch the encoder count, disable the drives and turn the shaft by hand
Yeah I thought ... but they say 500cpr on the motor and the INPUT_SCALE should be 2000 / 0 right?
oh so you're looking at the motor angle
I have to go to the dentist... be back later
if you command 25mm is the angle incorrect by the same amount or a different amount?
Good point I'll try it later .... but Ill think it be half the amount .... Oh Dear Dentist ... i'm runnig scared ... ;-)
Shame this does not spell check ... lol
Paragon36: regarding XY laser, I recall reading about setups having a Z axis with automatic height control to set the focal point correctly, I only mention this because I thought I could skip Z for my plasma setup but in the end I would have saved $ and time by having Z from the start
Thanks for the info Dallur. Regarding the Z Im going to set this manualy depending on material thickness which will be a flat no thicker than about 10mm.
Though saying that I guess it would be nice to press a button to set it ;-)
Paragon36: the problems start surfacing (no pun) when the under-surface is not even and when the item you are cutting stars warping because of heat :(
Paragon36: not sure it will be a problem but If I were in your shoes I would start by reading up on it
hooked up the x axis stepper last night and gave it a spin
ended up running 5v from the computer's psu for the drive's logic
eholmgren: that is what I do
I had no idea that wall warts were so horrible
in the manual for the centent drives I have
it mentions puting caps across the power terminals coming into the drive
since I'm running 3 drives/motors off of one 24v ~18 amp supply
would it be wise to do that in case all the drives try to pull too much at once
it can't hurt anything, and it probably reduces the voltage ripple measured at the drive
where is the max feedrate defined in emc2?
when I was having fun spinning my stepper back and forth last night
there is no such max
I noticed 72ipm was the fastest I could set it to jog
that's specified in your ini file
you need to match it to your machine
there's velocity and acceleration limits for each axis as well as the tooltip
axis looks at [TRAJ]MAX_VELOCITY to choose the highest value for that slider
yes that's correct because it's the tooltip velocity limit
cradek: altera does publish documentation on how to upload a program to their FPGAs, so writing a Linux application to do it shouldn't be a problem.
that's great news
I don't know the details of how this board is hooked up yet, so I don't know which of the multiple methods I'll have to implement
I envision that the HAL driver will have the firmware inside it, and simply upload it every time
that makes updates very nice
yeah -- I don't want to end up with a driver that has to support multiple firmware revs
do you have to write all the EPP handling code or is that already in there somehow?
no, you have to write it yourself
I think I get some example code with the device, but unless it's GPL I'll only be able to study it, not use it
look at "what files do you receive with the boards" on http://www.fpga4fun.com/board_pluto-P.html
I bought a "flashy" too, so maybe the first project I'll do is to make it provide a HAL alanlog signal
since then I won't have to concern myself with any of the details of writing the fpga software
hello all 'just got back'
looks very cool
Are you guys into something here as I don't want to interupt.
Paragon36: don't worry about it
in fact I'm sure cradek's bored with hearing me talk
yeah that's right
also, we all seem to have a knack for having more than one conversation at once
The question I have is regarding servo drive voltage. I have read that it is favourable to drive a servo higher than it's designed voltage. If this is true what voltage should one drive a 24v servo?
that's true for steppers, I don't think it's true for servos
Oh ok that may have been what I hve read ... duh
for steppers you constantly have to overcome the inductance as you turn each phase on and off. a higher voltage makes that happen more quickly.
often steppers are run at 10x or more the label voltage
for a DC servo that's not true
Yes that makes sense ....
How many i/o does that fpga have?
On another note comming back to dsPic servo project it state on the web site that a quadratic count is received from the parallel port can EMC2 generate this?
skunkworks: that board layout has "28+3 I/O pins available (the "+3" are one clock and two dedicated inputs). The IOs are 3.3V, but 5V tolerant - great to connect to legacy systems."
quadrature is much better than step/dir and I think new drives (that aren't made for use with legacy software) should use it
the chip itself has 100 pins so I think a lot of them must be unconnected
what driver do I need to select in .ini for this functionality?
you should look in the user manual under the HAL stepgen section
Paragon36: for quadrature output you change the step_type when you 'loadrt stepgen'
stepgen can generate all kinds of outputs
"step type 2"
heh jepler's faster than me
OK Ill take a look at the stepgen info... Thanks both of you :-)
[16:57:23] <jepler> http://linuxcnc.org/docs/HAL_Documentation.pdf
but some of the figures are cut off
Thanks Jepler I was just looking for it .... but you beat me to it by a good mile ... lol
Hey guys, wonder if you could give me your thoughts on selecting a CAM program for dxf to gcode
Dallur: are you using autocad?
sorry, I don't know then
cradek: np, I output dxf just like autocad
I wrote a simple autocad program for basic gcode interaction
(it runs inside autocad)
cradek: using G2/3 or just G1 ?
g2/3 for arcs
it translates polylines to g1/2/3 directly
there's some stuff for drill cycles etc too.
very basic but it does work right
cradek: how about path selection, how do you set the start/end and jumps ?
you can pick them in order if you want
then it does shallower cuts before deeper ones
for start/end it probably uses the direction the polyline was drawn
cradek: my stuff is all 2d so I don't even need the Z
someone keeps threatening to rewrite it in python to read dxf (no reliance on autocad then) but he hasn't done it yet
it's gpl if you feel up to trying that yourself
I am sure I saw a dxf to gcode converter just the other day but can I remember .... I just check my bookmarks!
reading dxf is a pain in the butt, but there are libraries
cradek: yup, I noticed a python lib for read/write dxf earlier, supposed to be pretty good
that would be a great start
cradek: do you just ignore splines or ?
it might be a fairly straightforward conversion from lisp to python then
my old autocad (12) approximates splined polylines with straight segments, so that's what you get in the output
cradek: I was going to say autocad can convert spline/pline
my version can only "smooth" which is a one-way conversion
not much real support for splines
gcode has no splines anyway - you HAVE to use g1 no matter what
(that's what truetype-tracer does)
the reason I am asking is that I got some pretty messed up lines.. probably easier to rebuild them all to polylines inside rhino and set the tolerances to something usefull
I don't understand
(I don't know anything about rhino)
is it cad or cam?
to be more exact
3d/4d does animation to
Dallur.... may have found one! But the link is on my other computer! Search google for '3d dxf toolpath to gcode converter' click cnczone.com 'search in page gcode converter' look at bottom ie last post there is a link for an upload .... it may work.
IParagon: hmm sheetcam or qcad ?
Paragon36: those are the only two cam programs for <$3000 that do G2/3 from dxf that I know off
Anyways, I got to run but I will check logs when I get home (im at work atm)
thanks for the info cradek, I will look into making a generic tool
Sorry Dallur I obviously missunderstood what you where after ...
cradek: it must have been wrote in lisp?
it's not very complicated... you could rewrite it for less than $3000!
a few hours work probably.
59 dollars. cheap. That would be very flexible.
4 axis - 2X4 encoders - 2X4 drive control - 16 of the i/o
skunkworks: you're looking at the "pluto-p"?
skunkworks: that's basically my project idea too
but I don't know thing one about FPGAs
skunkworks: the low number of I/Os seems to be a consequence of the board design more than the limits of the chip. The EP1K10TC100 has 66 total user I/O pins, including 4 dedicated inputs and 2 dedicated clocks.
how much for just the chip?
[17:56:54] <skunkworks> http://www.digikey.com/scripts/DkSearch/dksus.dll?Detail?Ref=207020&Row=227538&Site=US
granted - I don't think I could solder that ;)
cnc machine, but no smt reflow table?
I have seen people make them out of toaster ovens
Paragon36: The free (as in speech) cams i found are: opencam, gcam, cambam and cam.occ.
all are quite newly started projects
cambam is probably the most mature, but its .net based
has anyone here tried sheetcam or meshcam?
they seem to the best entry level priced cam progs
skunkworks: that URL didn't work for me, but I did find that part on digikey earlier and that sounds like the price I saw
looks like the ACEX is a "mature product" so availability might become a problem soon
they haven't discontinued it yet; they discontinued parts of the ACEX line with notice in 2002 and final orders in 2004
looks like the low-end of the current generation has around 3000 elements (instead of around 600; 5x as many) and costs about $11
their part numbers look like someone sneezed out a bunch of numbers and letters
it would be nice if you could use your code on a larger device once it's working
I think you have some freedom to do that
I have NFC how "portable" programs are, but surely one manufacturer will make sure I have a pretty good upgrade path to their new parts
do any of the rest of you have more projects than you can possibly finish?
does it stop you from choosing new projects?
I am in denial on what I think I can finish
I still have to build a sterling engine for my solar collector
but to do that I need the big mill runing - which means retrofit. :) and so on and so on
you've got it all wrong - first you're supposed to buy some new tools
I got back from work 40 minutes ago..
just had a sauna :)
and are getting dressed to go to the kiosk
oh, nice :D
trying to get my stuff ready for dreamhack..
oh, I never really fancied that
what's a kiosk?
a small shop
probably you call it a "stand"
candy store :)
I need a coke, and some chips.
eholmgren: you talking to me?
eholmgren: are you talking to _me_ ?
eholmgren: I know.. just sounded like in the movies :D
lots of them actually
the gun on the slide in that movie was cool
a kiosk can ususlly be referred to as an equivalent to 7/11
flip of the wrist and there's your deringer
looks like if I assume "1uS per outb" I can program the ACEX with a very simple loop without extra timing, at about 5uS per byte -- about 100ms total
I can't wait to get this hardware
this means your driver could have firmwares with different numbers of encoders, pwms, etc to maximize the leftover IOs
at 20kb per firmware you don't want too terribly many
it also complicates the linux side as well
Would you make the hal configurable - and then only the needed code would be uploaded to the fpga?
my first stab would probably just be a 4-axis pwm servo setup with an arbitrary split of the remaining pins between input and output
So you have a few coming?
Lerneaen_Hydra: actually kiosk means the same in english :)
hello emc , i hve two questions :1) can i use serial ports under emc2 additional to an parallelport 2) what frequency can i get with a 2 ghz machine ?
I don't recall hearing the term
atleast to www.webster.com
maybe in british/other locale, but I don't recall hearing it when in the US
[21:16:19] <anonimasu> http://www.webster.com/dictionary/kiosk
yaddha: use serial ports for what?
I have had a nightmare with the ubuntu live cd ..... the networking out of the box is flaky ... could not join irc .. some websites worked others did not ... the fix > ifconfig eth0 mtu 1492 ???
paragon36: never heard of that one
cradek: relais or stepperdriver
Yeah strange one! tcpdump reported oui unknown it apears to be an issue with certain ubuntu releases!
yaddha: there's new untested code in the devel version that hooks up the serial port handshaking lines to hal, but a second parallel port is probably better
serial ports use strange voltage levels of course
cradek :aahhh - have an epia with four serial ports -would be nice
cradek : epia board cl10000 -they use the serials for terminals etc so voltage should be stable at least -but anyway- ... speed would be no issue ?
like I said, it's untested
do report back if you try it
cradek : ok thanks . could you give me a hint about the possible frequency of a 2 ghz comp under emc204 ?
yaddha: almost all GHz+ computers seem to be able to do BASE_PERIOD=20000 (20us; max step rate 25kHz) and many go down to 10000 or even 7000
see also section 2.1 on http://wiki.linuxcnc.org/cgi-bin/emcinfo.pl?TroubleShooting
even my pentium III 667 could do 25kHz (20usec)
jepler : thanks - i remember that 500mhz give roughly 25 khz ... just didnt understand if thats linear or if there is a hard limit somewhere
*from the www page
the limit is the parallel port IO time
I think inb and outb still take about as long as they did on the ISA bus
for fast or slow machines, the time to transfer one byte of data to the parallel port is around 1uS. It takes 3 bytes to read and write the whole parport. So if you set base_period to 7000, that's 3000ns taken for the I/O, and about 8000 CPU cycles left to do stuff like transfer control to and from the realtime system, and to actually run the other applications...
jepler :+cradek :wow thanks , im not an electronic pro and just try to find out if i can get 100 khz with emc -so a pci card with lpt would be potentially faster ?
you might get 100kHz if you use quadrature instead of step/dir, but still probably not
a machine that requires such a high step rate is a bad match for software step generation
there are hardware step generating solutions like the one from pico systems
or, if you can reduce your microsteps by a factor of 2 or 4, you'll be in great shape
sorry to interrupt ... cradek was it your goodself or jepler that had setup a small lathe with servos?
that's me with a little help from everyone else
I don't know if PCI parallel cards are any faster
Could you do me a favour and post the PID setting that you have set with the etch-servo?
I think P is 80, I 120, D/FF are very small
paragon36: it is not a well-tuned machine by any stretch of the word, but here you go: http://cvs.linuxcnc.org/cgi-bin/cvsweb.cgi/emc2/configs/etch-servo/etch.ini?rev=1.5
it won't do you much good to use my numbers :-)
oh, you mean for the lathe
etch-servo isn't a lathe, it's a toy.
oh did I misunderstand?
PID tuning numbers vary greatly depending on the motor and the machine
hehehe it's got to be better than where I am right now ... :-)
don't you have a motor with nothing hooked to it?
cradek's motor's look almost identical to the pittman motors I have
I bet the mass hooked to them is more important than the motors themselves
I bet you can get your motor to turn correctly by setting P to something small, say 10-20, and everything else at 0
maybe just a tiny bit of D (0.1)
cradek : so emc + the pico could do 100khz stable ?
oh very easily
cradek are you motors 500cpr?
you should call up or email jon elson
paragon36: sorry I don't remember, but I am using a quadrature divider to get the count rate down to where it can be counted in software
paragon36: the scale ends up being 375 edges per mm of travel
would the INPUT_SCALE= 2000 / 0 be correct for 1mm revolution of motor in mm mode for a 500 cpr encoder?
sounds right if I understand your question correctly
you have 1mm leadscrews and you're going to couple directly to the motor?
Yes sorry.... 500 cpr gives 2000 resolution > so INPUT_SCALE = 2000 / 0 for one motor rev per mm of travel shown by EMC2 GUI
No the motor is stand alone for testing ... no lead screw or gearing
ok I understand, yes you're right
but I think you should just turn the motor by hand and see where the gui goes
then you do not have to worry whether or not you have a pid tuning problem
so if I want the motor to turn say 10 time per mm displayed would the input_scale be 20000 / 0 ?
that's the number of edges per user distance unit, which is mm in your case
One other thing what set the motor speed? you mentioned that you can get travel of 1500mm per min my motors dont seem to turn very fast at all. But when I connect the motor terminal directly to the power source they spin at like 6000 rpm for 24v (ie bypassing the L298 and EMC)
you set the maximum axis and tooltip velocities in the ini file
the velocities are in mm/sec so you have to factor in your scale to get motor rpm
cradek : thanks for info -i guess pico is the right choice -do you know any competitors ?
cradek: I have tried both Sheetcam and CamExpert(qcam) and they are both horrible at converting dxf to gcode :(
cradek: and those are the two I identified as the "best" ones for <3000
Rugludallur: sorry to hear that, for what you want (2d only) it's such a straightforward task
Rugludallur: you could buy autocad and use my software for that price.
cradek: yup, but I'm not a big autocad fan :P
[21:58:28] <cradek> http://timeguy.com/cradek/autocad
cradek: there is something I was thinking about while driving home
cradek: seems to me these apps are solving the problem from the wrong end, all of them seem to read in dxf, find polylines, simplify
while what they should be doing is taking the resolution of the machine
have you tried ace converter?
rendering the vectors in a grid, look at the grid outcome and auto optimize arcs/lines
skunkworks: ace did a horrible job :(
Rugludallur: I think I disagree - gcode is machine-independent and you should not have to know the machine's resolution to generate it
skunkworks: most edges looked like saw blades after ace was done with them
I've seen that a lot
very bad algorithms
cradek : thank you - saw that -there is only pico -guess this it will be - have a nice evening
are we converting splines?
I guess I have not had good luck with that. I normally have to explode them into line segments.
cradek: qcad only does G1, no G2 or G3 so that's out
you can't use G2/3 for splines can you?
I guess I don't know what splines can be in a dxf, my autocad only has arcs
cradek: variable radius arcs
we have a program called bezarc that takes illistrator files and fits arcs to the curves
Rugludallur: you mean a polyline made up of (circular) arcs, each with different radii?
cradek: more like no fixed radius, the arc can only be represented as a formula since the radius is ever changing
I know what a spline is
I just didn't think you could specify one in dxf
sounds like a spline
(realize certainly doesn't handle them)
I was trying to find out if *you* know what a spline is :-)
* alex_joni knows
cradek: hmm I might just be asking to much, I figured that there would be algorithms which would map arcs and lines to splines by approximatino
like I say - I have always had to convert them to short line segments for them to work
Rugludallur: the common algorithm recursively subdivides the arc until the error is within tolerance, then outputs it as straight segments
I don't know if using arcs might help in some cases - it might
but most splines aren't very arc-like, like you said (changing radius everywhere)
it seems hard to fit an arc over an arbotrary curve
that's why straight segments are used, they work for every curve, you just have to figure out how many to use
cradek: im just a bit scared that my steppers won't like that :P
that's why emc blends the motions
it'll be fine, just try it :-)
or doesn't blend, but decrese speed
to stay within machine limits
less speed!=good for plasma :(
Rugludallur: I know..
I might just try it out and see how it goes, it might not be an issue after all
guess you want the blending then
it's turned on by default
you can turn it off (exact path), or specify the max deviation
probably, but blending means less accuracy .. so .. it's a compromise
you can't have both unless your machine has no mass and huge drives ;)
get a machine that can do 5g's accel
but if your output looks like saw blades, you're not going to get very good results
and you won't have that issue at all
if it's just lines approximating the curve (not zigzagging back and forth) it'll work quite well
ok, the other option is to go back to the cad and rebuild polylines as arcs and lines
if you do that, and this is just one file you need done, I can convert it with realize for you
cradek: the fpga software says that the single quadrature counter with 16-bit counter and no index pulse takes 4% of the device.
I guess there are a lot of 4s in 100
I bet you can fit everything you want
cradek: thanks but It's a pretty big file, like a complete set of plates for a sailboat :P
sounds like too much work to recreate
cradek: you could build yourself one too :)
cradek: 6 weeks
milled wood :D
Rugludallur: how about asking on the list?
please excuse me for saying you should have figured out the gcode export before working 6 weeks
maybe there are people with good commercial CAM out there that are willing to give it a shot
I know LH has some
that's a good idea
Rugludallur: it won't be much of a PITA for them to convert it to g-code as a small favour
Rugludallur: just ask Lernaen_Hydra when he's around
Yup, but I expect this will be an ongoing project, since it's the first time this boat is built there will be adjustments and such
Hi all. I have just installed the EMC2 Live CD and cannot log on as root. Does anybody know the root password of the Ubuntu 6.06 EMC2 Live CD??
Ill find a way :D
mikejradz: the ubuntu way is to use sudo - search google for help
ignore the first url
there you go, a friendlier helper
Rugludallur: maybe as a pointer what CAM might be usefull
Rugludallur: various testing versions out there (limited for linux though)
I know synergy might work
mikejradz: are you blumpie?
skunkworks: that's a very personal question
Skunkworks: what is a blumpie
ok - never mind - someone just asked a similar question on cnczone
yeah, I'd like to know that too :D
hmm, I searched for blumpie on urbandictionary.com - I don't recommend bothering
alex_joni: Thanks, Im on a win box now testing sheetcam and installing more stuff than I care to put in the registry, testing the converters 1 by 1 :D
[22:24:04] <skunkworks> http://www.cnczone.com/forums/showthread.php?t=27743
evening my litttle elves
are we well?#
[22:26:31] <cradek> http://www.urbandictionary.com/define.php?term=STFW
do I need to look at that CNC zone link, or shall I just assume its some complete noob giving crazy advice?
(definition #1 by the way)
wanted to ask you something
was it: "will you marry me and have my babies?"
I don't think that's even possible robin_sz
robin_sz: close, but not that
well, you may have a point
robin_sz: was wondering if you still have contact with Dan Taylor
anything's worth a try once though I suppose
goodnight, gotta run
alex_joni, yeah, occasionally ..... and another plasma maker now too
thanks for the advice cradek :D
robin_sz: have a potential request for one of his machines
ooh ... interesting ...
talked to him on the phone the other day
small and cheapish one?
Jepler: We were talking a few days ago about tangental knife control. I would like to work on developing a hal module to do that for public use.
eyah VERY nice guy
oh, biggy :)
you should also look at Techserv
I also have a request for a 3x12m
mikejradz: for blade cutting?
actually, Dan's machines are made in .ro, so it shoudl be good for you anyway
I saw your thread on "rotating blade question" and am going to start looking into how to make it happen.
[22:31:45] <robin_sz> http://www.techserv.co.uk/
their small machine is brilliant
[22:32:11] <robin_sz> http://www.bluemarlin.biz
a very nice and neat small plasma
robin_sz: been talking to these guys: http://www.powercontrol.hu/
ahh, hungarians. you know what they say.
alex_joni: Yes for blade cutting
for cutting what?
hungarians are the sort of people who enter a revolving door behind you yet still come out in front of you ;)
there's a ~1m long helical blade in the cutter at the end of my printer at work
Paperboard and corrugated material.
a blade .. what you need is a laser :)
single blade curved along the length of the shaft
my mate got a nice 25w CO2 this evening for $trivial
Laser chars the edge of the material and leaves a kerf.
eholmgren: so I guess the thing is to detect the direction vector
and rotate the shaft accordingly
hard to see the charred edge if done right
That is the plan.
we have zunnd cutters at work - very cool
yeah .. thats a C axis
err... mikejradz: ..
maybe that spelling isn;t right
skunkworks: that is exactly the principal. I have similar tables.
robin_sz: you can do it in CAM if it can.. but I suspect that might be somehow expensive
mikejradz: are you going to have a moving conver belt?
alex_joni, many commercial systems have automatic C axis built into the control
alex_joni, its fairly trivial to code
There will be a roll feed and a moving table
mikejradz: doesn't seem too hard to keep the last direction vector, and check for new positions and adapt
you just need to wait for it to rotate at 90 degree corners ...
robin_sc: at 90 degree corners the blade should lift turn and plunge.
eek.. that's harder
and at 89 degree corners?
but you can probably still do it
[22:38:25] <skunkworks> http://www.zund.com/media/cutter/cutterlinien/images/m-800-sf-gross.jpg
robin_sz: lift (degrees mod 90)/10 mm
we have 3 of those. they work quite well.
The blade would stay in the material up to some predetermined angle lets say 45 degree for example tighter angle would require lift.
it cuts on the conveyor
skunkworks: I looked at one of those and they are sweet.
skunkworks: what do you use them to cut??
lots of things - we are a printing company. Mostly low quantity jobs that would be too expensive to make a die
polycarbonate - vinyles
I worked for many years in printing companys. Primarily folding carton companys.
Are you a structural designer?
No - i keep thier network running
An IT guy, got it.
Well those tables are exactly the functionality I intend to work on.
alex_joni: mind if I ask a trollish question ?
alex_joni: How many people have thought about adding a custom g code for splines and do you know if anyone has done it ?
It has a vison system to register parts.. I would not know where to start :)
I know jepler was discussing it lately
and he added some link to a certain paper that discusses this to the wiki
* alex_joni knows no more than that
alex_joni: hmm ill check that out
I have a prototype machine that was running emc from about a year ago. I just installed the new Ubuntu 6.06 Live DC and cannot customize the setup.
Rugludallur: bug jeff later :)
look for CustomizingConfigs on ubuntu
alex_joni: I will :D
The different example setups are in a root only directory. You modify the ini files and are not allowed to save them.
mikejradz: yes, you need to copy one of the sample configs to your dir, and play there
mikejradz: usually to /home/user/emc2/configs/yourmachine/
that will show up in the config picker emc brings up when starting
the wiki describes all you need to do/know
alex_joni: Thank you so much!! That is probably all the nudge I need to get going.
mikejradz: no problem
I think the manual also has this kind of info :)
alex_joni: I must have overlooked it.
I was following a printed manual and didn't see that info.
mikejradz: the 2.1 manual (for the upcoming release) has a lot of improvements
it might be usefull lecture
alex_joni: Is the 2.1 manual available for download?
it's available as pdf and html
mikejradz: we (I) appreciate any hints how to make it better
I am working from the 2.0 version. I will printout the newer one.
mikejradz: some commands/instructions might not be directly applicable
on a side note. finally got back to this project
[22:56:48] <skunkworks> http://www.electronicsam.com/images/house/shower.JPG
[22:57:14] <skunkworks> http://www.electronicsam.com/images/house/tubsur.JPG
next is taping and tile yay
alex_joni: 2#$%$#3 someone has a patent for using splines directly as a cnc control input !
yeah, for B-splines
or any other spline :D
alex_joni: I would imagine that there must have been prior art though
Is it possible to run off the Live CD and point it to config files on floppy or host hard drive?
you can do "emc path/to/inifile.ini" from a terminal
That I will have to try
mikejradz: remember to put all the files you need in a folder
.nml .tbl .var .hal etc
alex_joni: you seem to be a person in the know.
cradek: If you read logs I checked with dxf and it turns out V12 does not have spline support, later versions do, this is a good thing since having rhino save as v12 enables me to export as aproximated curves which are much better than what the cam tools can create
mikejradz: a bit :)
good night all
Rugludallur: it it night there?
alex: it's always night this time of year :P
Rugludallur: yeah, that's what I was asking
don't you hibernate? :-P
sunrise is at 10:20 and sunset is at 4
Nahh, you get used to it
I could live with getting up at 10:20 :)
heck .. I already do that sometimes
mikejradz: lots of other skilled people around here
alex_joni: so could I :D
mikejradz: might just be a while till you get your question answered
I know nothing.
* A-L-P-H-A pokes alex_joni... go to sleep.
you are getting sleepy!
I have been sleepy for the last couple of hours
I can wait. I intend to contribute a vector knife controll at some point in the future.
you are getting very sleepy... your eyes are getting heavy... they are slowly closing.
mikejradz make sure to contribute the source of the replacement blades too!
I just use X-acto
and plenty cheap
but I hear they dont' do as well as some of the speciality blades
a la drag knife
Drag knife may work for vinyl but thicker stuff needs tangental control
As long as it works for vunyl and mat board, I'd be happy
vinyl should work well, mat board may be difficult depending on thickness. I have seen some 1/8 inch thick. That is mighty dificult to plow through.