fenn_ is now known as fenn
user__ is now known as SkinnYPuPP
Just this once .. here's the log: http://www.linuxcnc.org/irc/irc.freenode.net:6667/emc/2008-10-21.txt
picky lil' bot :o
how can i backup my system and drivers ?
SWPadnos_ is now known as SWPadnos
[14:29:56] <skunkworks> http://voodoocnc.com/
[14:30:11] <skunkworks> http://www.cnczone.com/forums/showthread.php?t=18861&page=11
hi, anybody has login access to the opencores.org web?
cncman: you need some file from there?
swpadnos is helping me
went to talk by mach3 guys in UK, interesting what the can and canot do
can=custom screens and reasonably easy extensions with VB-like stuff
seems its under new ownership
yep - Brian is it?
yes he gave talk on cutting speeds/feeds that I went to
yep - seen that
I have only met the retired art. Was brian at the cncfest?
huh - I missed him then.
(bsd license modbus implementation, includes ports to various micros)
yeah - that's a target library, right?
SWPadnos: not sure if it's target only
ah ok - they have a master module as well (in CVS)
modbus is actually pretty trivial to implement - it's all the junk around serial port error checking that's a PITA
saw a guy demoing his cam software and snap his endmill :)
somehow that reminds me of bill gates
it's only fun until someone loses an eye
SWPadnos: or a nut
well, I suppose
it stayed stuck in the ally he went too deep in
thus proving that software lets you make mistakes much more quickly and efficiently
cut air first :)
archivist: air isn't free you know...
some of the chinese mills and lathes seem acceptable quality these days
don't assume that China can't make good stuff
they have a lower minimum quality, but very nearly the same high quality limit as elsewhere
I quite like the taiwanese ones at work
mighty fine machines in terms of maintenance too
there is still some crap being imported specially rotary and xy tables
man - 4GB of RAM, $45
SWPadnos: :o bargain
it's not the fastest available, DDR2/800 at 5-5-5-18
800 is plenty
I've totally lost track of the meaning of RAM specs
you should see the list of timings you can adjust on the ASUS Rampage Extreme motherboard
there are about 30-40 of them
they should just put a checkbox: [ ] Gain 5% performance and lose 100% reliability
they have that too ;)
bleh whats wrong with old fashioned delay lines to get timing
there's a separate "step up" setting
you can do normal, faster, extreme, and crazy
or something like that, but I know that "Crazy" is one of the options
SWPadnos: how about "Crazy" with 1200Mhz ECC ram?
I'll bet you need JEDEC settings for that
ie, not all that fast
hm, this so-called modbus spec (MODBUS Application Protocol Specification V1.1b) doesn't define what the CRC algorithm/polynomial is
1021 I bet. there are tables in the source
r is that 1042? hmmm
it's described in "Modicon Modbus Prococol Reference Guide PI-MBUS-300 Rev. J" but there's a big note that says it's an obsolete specifcication, not to be used for new implementations
oh I guess I should be reading "Modbus Serial Line Protocol and Implementation Guide V1.02" for this information.
that seems likely
why'd they put the obsolete doc above the current doc on their page? duh
I think it's the CCITT polynomial (on wikipedia)
I wonder if that's the most recent version of the Modicon-specific protocol, before it was released as an open-ish standard??
huh -- a delay of more than 1.5 character times during a message is an error condition in modbus. I see what you mean about error handling being the difficult part of this standard
it's almost always that way with serial ports, in my experience
(haha, wtf, at the bottom of that page they have a "remark" that you should actually ignore that requirement and use a different requirement instead)
they're unreliable, and it's har d to decide how long is too long (considering that a valid 300-baud byte takes an eternity in CPU cycles)
if the cpu sucks the data fast enough AND there is no noise on the line AND the handshake works as advertised, serial should never lose data
hm and you don't know the packet length up front, so you have to do something like rely on dead time on the serial line to determine a packet is complete
takes me back a few years
you're right. it shouldn't lose data
you know the packet length once you've received the number of elements field (I think)
(you can know it by looking at the early bytes of the ADU if it's been reliably received, but you don't know that until you've received the end of the PDU and checked the CRC)
Either their explanation of the "CRC" algorithm is wrong, or they're describing a nonstandard variant of CRC
too bad they give no test vectors
they say that "(if the LSB was 0): Repeat step 3 (another shift). (if the LSB was 1): Exclusive OR the CRC register with the polynomial value"
(sounds like for a 0 bit you shift twice or until you get a non-0 bit or something)
HAL9000 is now known as SkinnYPupP
oh, if I had a camcorder, I'd show you the beauty of my PWM LED
thanks, but I have dimmer switches
so I've seen it before
I did RGB pwm leds for a job
* archivist has PIC coded it
archivist: which model?
oh, *that* one.
I could fall asleep watching this thing
I guess now wouldn't be the time to mention the 16-channel PWM LED controller I designed/programmed, for theater effects ... :)
if the boss catches me sleeping on the job, I could blame it on the project
SWPadnos: ahhhhhhhh. *yawn*
using an AVR and software PWM
16-channels? meaning 16 different, independent PWM outputs?
with programmable sets of transitions, blinking, marquees, etc, clocked by external triggers
oh yeah, I have a vague recollection that you had a clever trick for the software pwm
using software PWM
yep, vaguely clever, that's me :)
using a timer, though, right?
compare and shift - the compare puts the result of the comparison in the carry, so you end up with a byte to output directly
no, no timer
who needs timers
then how do you delay?
maddash: there aren't 16 compare registers in any avr
it did a couple of kHz PWM, with 8-bit resolution
what, you didn't do pdm?
all the cool kids do pdm now
one counter for PWM, one each for PDM
also, using PWM made sure that the LEDs are all off during the end-of-loop processing (reloading counts, checking inputs, doing fades, etc)
this was capable of running 2-4A per channel, at voltages up to 36V
and we used 4 of these boards on one show
or was it 5?
meh. bbrb, pharmacy.
hmm - http://imagebin.ca/view/vUIHJyy.html
That is .1v per div
voltage across the sense resistor
is that probe ringing or real?
* skunkworks should calibrat it..
you're not going to get spikes that big from ring alone, but it could be a part of it
what's the horizontal scale, and the scope bandwidth?
well - it looks fine from the scope square wave.
is that a 0.01-ohm sense resistor? (so roughly 10A)
yes - .015
and the timebase of the trace?
* archivist would expand the ringing to see frequency
[20:09:20] <skunkworks> http://imagebin.ca/view/PGrgFY.html
seems fast-ish to me, but I'm no expert
(the first trace that is)
Someone was playing with the scope. The first trace should be 20khz
the calibrate knob was turned all the way
so - the 70kh should be 20khz. I just measured it.
which is what the pluto puts out.
ok, that's the frequency of the ringing you're getting
wow - the ring is at around 20mhz?
uh - oh, so the second image had CAL problems too?
it's bad to start typing when your mail reader has focus
[20:18:35] <skunkworks> http://imagebin.ca/view/6U3eikh.html
interesting secondary ring 3 divs in
cable effects probably
Hi guys... I'd love to get some help with my lathe config... it stopped working: Axis works, but my parport does not seem to get any signal. The config for my milling (not generated by stepconf) is still working as before. Any idea on how to troubleshoot this?
the lathe config was working but then it stopped?
hardware fail on the lathe?
It was working when I first made it with stepconf wizard. Now I can't even make the motors work from stepconf wizard
Hardware is ok, I can use it with my milling config
what did you change or update since it last worked?
I can't think of anything beside the ubuntu updates
the file /var/log/dpkg.log shows what packages were changed on what dates. If you find a linux-image, rtai-modules, or emc2 package update since the last time you know your configuration worked, then it could be due to that.
then you can experimentally downgrade the package to the old version and see whether that changes the behavior. Example:: sudo apt-get install emc2=1:2.2.5
(later, to go back to "the latest version", "sudo apt-get install emc2")
if you establish that a particular version of a particular package works, but another doesn't, then that helps us figure out what problem we introduced.
(only go down this route if you're really certain that nothing about your hardware or your configuration files has changed, since it's a bit time consuming -- you should probably reboot each time you want to try with a different package version, just to make sure nothing is hanging around. for sure after changing linux-image-rtai)
are you positive this is the pattern you are seeing? I've had a problem where the first run of EMC after a reboot would drive the parallel port, and subsequent ones would not
* maddash checks for signs of "software pwm" in the logs
ramp gen is to A/D as PWM+low-pass filter is to D/A?
You are right about the time consumption... the dpkg log files are huge, and there is no change in the emc package during that time. I suspect the rtai update is to blame, but I still have a config that works (for my mill). I can restart emc without problems
How can I know my parport adress?
it's extremely unlikely that rtai cares whether emc is running a mill or lathe configuration. I really suspect changing pacakges is the wrong approach to troubleshooting this
as root: 'modprobe parport_pc && dmesg|grep -i parport ; modprobe -r parport_pc'
maddash: both commands give me empty results
isn't there a probe_parport hal module somewhere?
Hugomatic: when you load the parport_pc module, you should see some messages in "dmesg|tail"
maddash: how do I load the parport_pc module?
sudo modprobe parport_pc
that won't work if parport_pc is blacklisted (like it should be)
you can insmod the file directly though
dmesg tells me I have ppdev, and that "sysfs: duplicate filename 'parport_pc' can not be created"
meh why would it be blacklisted?
Hugomatic: find /lib/ -iname "*parport*"
maddash: because it interferes with emc
cradek: right, but were you trying to say that the emc installation autoblacklists parport_pc? because that's not very nice
I get 5 files listed in: /lib/modules/2.6.24-16-rtai/kernel/drivers/parport
yes it does
what if I have two different kernels, A and B, where booting into A is for emc, and booting into B is for parport_pc fun?
then you'll have to do something about it - but we have not yet run into someone who unplugs their mill, reboots, and plugs in a printer, then reboots and plugs the mill back in. this is exactly what 99.9% of emc users want to happen (i.e. emc/parport works)
then you need to reboot every time you change what you're doing
it's very presumptous of emc to start touching my /etc/modprobe.d/ files without my consent
Both my configs (the working mill one and the broken stepconf one) have "loadrt hal_parport cfg=0x378" in the hal files so this is not the problem.
The Emc HAL scope and the HAL configuration both show me that the pins are 'live', but the mototrs don't move
sure the lathe setup is not just misconfigured? lathe needs some enable signal maybe?
I don't think so, because AXIS moves the tool as if everything was OK.
I mean the lathe hardware
cradek: its a Sherline lathe, its very simple
how have you determined the hardware is working? is it the same driver, power supply, etc, you use with the mill?
I'm trying to understand what troubleshooting you have done so far
I can run the mill config connected to the lathe motors,
Hugomatic, check the port setup and make sure the lathe settings match the mill config settings
ort are you saying that the computer with the mill setup also turns the lathe motors, but a different PC with the lathe setup doesnt?
"<Hugomatic> Hi guys... I'd love to get some help with my lathe config... it stopped working" -- from this I thought I understood that at one point the lathe configuration worked. but it sounds less like that was ever the case.
jepler: I have to admit you are right. I have found that my config is not working when I select "Sherline" as the driver type in stepconf, so I may have edited it without checking it, and only found the problem today.
that option only sets the step timing or the step/dir arrangement. it does nothing else related to a Sherline machine
it's come to my attention recently that (A) the sherline timings in stepconf are not right and (B) nobody can actually tell me what the right sherline timings are and (C) they may require such long "step length" timings that stepconf will never write a correct configuration file.
ooh quittin' time
Just been playing around with polymorph plastic. Awsome stuff :-)
hmm not seen that before Paragon looks nice to test a casting method out
that's the stuff reprap uses
Thats right fenn I saw it on the link you showed us http://reprap.org/bin/view/Main/AssemblingDarwinMachinery#Z_belt
I have made one of the the timing belt pulles in the method explained.
Im more used to lead casting
Paragon: did it work?
I made the mold out of it too. it machined well but one need to take it slow due to it's low melting point.
heh then just throw your chips into a pot of water right?
The timing belt fits well but i have not tried it in the field as yet
Thats right and re-use
where did you get it btw?
I am think of making a motor mount out of it and maybe motor coupling too.
one sec I find the link...
I found Maplin sells it over here
Very expensinve in Mapplin! I bought 2kg from http://www.tomps.com/shop/advanced_search_result.php?keywords=polymorph&x=0&y=0
Ebay has it listed too.
£12.86 per KG + vat + delivery
ren-shape might be ok for a couple shot low pressure mold ours
I am trying to find a moldable plastic that melts say around 100C but no luck yet
dmess: thats a resin right?
we used to get cubes... its like micro-bubbles and resin
Just found it on google. its made by huntman
cuts well.. lasts in h2o for a while.. we used them as prototype pulp moulds
One thing I will say the polymorph when hardened is very tough indeed
ive never heard of it
I wonder how long it lasts, as some plastics die with age
all die with sunlight..
Not sure how long it last but I think quite a while. But it's good for proto work. I read somewhere it has over 500 mpa. that will probably mean more to guys then me. ;-)
It's Biodegradable in soil too.
Tensile Strength: 580 kg/cm² Is that strong?
7075-T6 alli is around 506MPA give u an idea
roberth: I think I got the mpa wrong ;-) I meant 580 kg/cm²
Paragon, this site is pritty nice for material spec and conversions, http://www.matweb.com
taking a look now...
search the material name and i will give u a list, nice for them materials ur not sure on
From the search on it showed multiple listing for Polycaprolactone but I think the mpa is around 65 ish
[22:34:26] <Paragon> http://en.wikipedia.org/wiki/Polycaprolactone
yea its not a lot on conversion into mpa depends on its other properties
It can even be used as a biomaterial in medical implantable applications ... look out james bond ;-)
Check out this stuff ... http://en.wikipedia.org/wiki/Plastarch_material