I need fine tooth hole saws
ice core drills
good idea, they probably aren't fine toot though
you know how you can tell winter is over in Wisconsin?
first car goes through the ice into the lake
always a welcome sign
there they go again :)
you think we could type fast enough that they could log one of our messages before being kicked?
why are you driving over a lake in a car?
I didn't, people go ice fishing there
they drive their cars out to their ice fishing shacks
the shacks stay out all winter
first car goes in, the shacks are all gone the next day
the part I don't know is if they drive out to get their shacks, seems iffy
they're usually on skis and reasonably light, so you can either pull them with a couple of friends or use an ATV or snowmobile
rather than your jacked up 4x4 pickup truck
do the people up your way wait for the first car to go for a swim?
no, there's usually a thaw that lets one or more in, so they stay out longer :)
there are races on the ice every weekend
there's even a posted speed limit and police patrols :)
I don't know if the ice has been thick enough for that in the last few years though
the lake I lived next to had a pond next to it, I went out cross country skiing on it, got most of the way across before I realized it was soft. So I skied back
I haven't been driving on the lake since I was in high school
had a funny experience though
we decided to drive from Burlington to Shelburne on the ice, about 7 miles
so we're cruising on the lake (at 70 or so), wondering what we'd do if we had to stop or something
when Event #1 comes up: there's a 4 inch or so break in the ice, like a curb
so we tried to slow down a little, but didn't really, and slammed into it, hard
didn't lose any tires, so we kept on going
we noticed a snowmobile track, so we decided to follow that
until the track ended in a puddle (Event #2)
stop, drill a hole, see how thick the ice is just to be safe :) eheh
we decided to turn back at that point :)
i wanna ride my atv on lake erie, wanna drive out to one of the islands
hope the ice gets thick enough
so we're pulling off the lake at the boat launch (nice ramp, you know), and the mufler falls off the car (into a puddle) (Event #3)
I was laughing so hard I couldn't get out of the car to pick it up - my friend had to go out for it
then I had to tell the story to my mother (whose car we were using ...)
those were the days :)
so when you said "we", you meant "I"
err, kind of
what you mean we, kemosabe? :)
I did happen to be driving when the muffler fell off
town where I lived in Wi. had a really cool library, it is stone and has towers like the mcmansions do nowadays
doesn't look that impressive from google street view though
street view is fun
[03:04:49] <JymmmEMC> http://finance.yahoo.com/family-home/article/106466/Where-You-Won%27t-Shop-in-2009
SWPadnos: driving or lo altitude flying =)
* archivist puts blindfold on, sticks 5 pins in donkeys, and returns email
is there any way to get tool info from EMC ? and/or tools count in *.tbl file ?
is it possible to obtain a cnc mill for pcb purposes that can do 8mil class double sided boards?
lpkf claims 4mil pitch: http://www.lpkfusa.com/protomat/s-series.htm
so it laser cuts all holes and vias
all laser products will be outside my budget
nearly all cnc pcbs out there have the pad holes poorly lined up to the pads http://www.robio.be/cnc/final/Floating/NEW/PCB_detail_A.JPG
[12:30:11] <skunkworks> http://www.electronicsam.com/images/KandT/servostart/schem/newcurrentlimit/top.JPG
[12:30:22] <skunkworks> http://www.electronicsam.com/images/KandT/servostart/schem/newcurrentlimit/bottom.JPG
^ home made pos
mr_boo, can only be due to poor process, use a couple of holes to register the pcb in exactly the same position for each setting
i believe one drill holes and mill in the same setup
skunkworks: those holes aren't centered in the pads
mr_boo: not laser, it's a high speed spindle
still probably out of your budget
wonder if one could get an affordable cnc mill that can do fine pitched smd boards
maybe few people use cnc for pcb making
micges: python -c 'import emc; s = emc.stat(); s.poll(); print s.tool_table'
skunkworks: the holes were much better lined up on the bottom side of your board
why can't ass kicking cnc mills be available for affordable prices?
either affordable and piece of junk or ridiciously pricey
the sable-2015 proved to be a hoax after all
affordable == ~ $500 ish
not affordable == ~ $5000 and up
i'm just a guy an my name is not general motors
i don't care about the latest development of laser and waterjets
in between 500 and 5000 and you can either retrofit a commercial old machine or make something
i want something for _my_ wallet and not a big company like toyota or something like that
this is from the sable-2015 http://img411.imageshack.us/my.php?image=dscn0333qr0.jpg
hope i can get better than that for $500
look at the pads at the bottom xD
cheapo machines dont have ballscrews
wonder if the ballscrews themselves cost ridicioulus amounts
or just the machine involving them
the nut is expensive and a ground screw is
i want this performance for $500 http://members.home.nl/hobbycorner/images/Q2.JPG
easy go to a PCB maker and ask them to do it
well outside $500 for my boards
personally when you talk about spending a big sum like $500, I feel it should buy a car or a house, not just a CNC machine.
mine was built from scraps /me being a cheap ...
certainly not this http://img411.imageshack.us/my.php?image=dscn0333qr0.jpg
then i could just burn the money
i can drill by hand better than that
the good machine companies are so frickin posh
as long as a cnc is usable the price immediately jumps up to another level
the anti-backlash system of the sable doesn't appear to work at all
archivist: btw, how did you make yours so that it became high precision? ballscrew equipped?
($500 houses: http://ask.metafilter.com/112391/Why-arent-people-buying-cheap-houses
mr_boo, its not high precision yet, as I dont have bass screws, but I also control the gcode to work in a controlled manner to avoid backlash
mr_boo, btw emc2 does have backlash compensation
skunkworks board looked fine on one side
jepler: a few years ago, I stumbled upon a couple of "lost detroit" websites
they were fascinating, mansions and skyscrapers abandoned
skunkworks: just ran across this and was reminded of your troubles in current sensing: http://www.sparkfun.com/commerce/product_info.php?products_id=9028
with the INA169 "current shunt monitor", you aren't trying to measure current by a GND-referenced current sense resistor
otoh it's limited to 60V so it's probably not good enough for your application
(and that's the model with the high common-mode input range)
from the name, I think that is for rc aircraft
there is a vaporware autopilot with that name
eric_unterhausen: yeah that specific board is
i see it hidden in the datasheet
he actually shipped out beta units over a year agoa
but he wants to do all the coding himself, needs to open source the thing
probably shouldn't use ground reference for current sensor, differential amp the voltage
across the resistor
I'm using the hall effect sensors because money is no object
from TI datasheet The input circuitry of the INA139 can accurately measure beyond its power-supply voltage, V+
so its being used correctly
eric_unterhausen: "differential amp across the resistor" is exactly what the INA169 does
the voltages at the op-amp inputs can be 60V with respect to GND
now I'm thinking that if you have 60v across your sense resistor, something is drastically wrong
and datasheet has a bipolar circuit using two and a comparator
I was looking at sense resistors that would develop 1/2v at full amps
the voltage across the sense resistor is small, but the voltage between GND and the sense resistor may be quite large
because it goes across an isolation barrier?
have a look at page 2 http://focus.ti.com/lit/ds/symlink/ina139-q1.pdf
using it on the high side is a good way to drive up costs
the chip has a cost of $1.45 ea @ qty 1k which I'll grant you is much higher than $0
if there is a high impedance path back to ground from your sense resistor, use that as the sense resistor
real sense resistor has known parameters
I have a $10000 impedance meter
but it is a silly idea anyway
they dont respond at speed in a circuit
you're saying they have too much inductance/capacitance?
oh, the meter was to characterize the return path to ground
I wouldn't consider myself enough of an expert to argue whether high-side or low-side current sense is better. Instead I'll take the postition that "it depends"
it's not a better/worse question, one is cheap the other expensive
the current is the same either way, it's not leaving through a hidden exit
Pardon me which one is expensive?
unless the exit is hidden by smoke
at microwaves there are plenty of exits
found an interesting comment in an HP doc about the slits on a BNC letting out 4 gig and above
high side current sense is much more expensive
hah, I think they forgot a few lines in this sample application: http://focus.ti.com/en/graphics/aap/general/figure3.gif
there seems to be a problem
All of our little PWM bridges use differential low side sensing
It also allows a little gain before the comparator
so a lower value (less power) sense resistor can be used
I thought I saw you were using a hall sensor, reading comprehension must be low
On our 8I20 (3 phase vector drive) we use halls
Just this once .. here's the log: http://www.linuxcnc.org/irc/irc.freenode.net:6667/emc/2009-01-23.txt
I am using a lot of stuff I have. So that explains my setup.
Halls have their own problems: bandwidth and noise
but for three phase current control we get a better
current sensing with the Halls. Its tough to get good
current sampling in low side current sense resistors
with three phases because you are trying to recover
a low frequency current signal out of the high frequency
switching signal, using Hals sidesteps the issue
* skunkworks_ wings it a lot which gets him in trouble.
it works, right?
Like not thinking about negative voltages across the sense resistor getting into the lm393 comparator. (not it has a schoctty diode across the comparator input)
puts the lm393 into an 'unknown state' ;) go figure
Yep common mode range is _really_ important!
now you tell me.. ;)
thats the nice bit of the INA 169 device it out side its supply rail
skunkworks_, do you have a differential amplifier connected to the sense resistor (both sides)?
no - common ground
Its a little fancier in that the comparator output goes into a CPLD
so is only sampled when the correct side is on and after blanking time
Yes, no common ground
skunkworks_, that could also cause issues since the voltage on the high side of the sense resistor includes impedance from the traces leading to the low side
is that resistor actually 15 mOhm?
.015ohms - sorry
on, that's 15 milliohm :)
skunkworks_, the ground side of the resistor(s) goes to a big plane, right?
it is the one spot that logic ground it connected to motor ground. (thru the kelvin connection of the sense resistor)
if that make sense :)
sure, more or less :)
so theoretically, the logic ground should follow the potential at the negative terminal of the sense resistor
hmm not sure about that current measuring, I see possibilities of the logic current effecting the sense
you know those things that you hookup near your spindle and either run water or air compressor through (for cooling or whatnot), they are really adjustable, what are those called? I'm hoping to get some that are larger, meant for lots of airflow
I have actually re-aranged the layout a bit after having to add a few things..... The input to the optos are a bit more isolated and the mosfets can sit against the back of the circuit board.. Last revision - I swear.
[16:39:49] <skunkworks_> http://imagebin.ca/popup/aG0eom.html
it also 'I think' helps the current sense also. (the comparator is in its own spot)
hmm, they are usually flexible, made up of multiple parts, so not exactly a coolant nozzle
yea, flexible coolant nozzles works, cool
this kind of thing? http://www.use-enco.com/CGI/INSRIT?PARTPG=INSRAR2&PMAKA=319-3859&PMPXNO=19507223
[16:41:52] <SWPadnos> http://www.loc-line.com/
precisely, hey thanks :)
even cooler: http://www.spidercool.com/
oh those loc line things are cool
ahh, i actually dont' want them for cooling
i just wanted a flexible yet rigid tube
i wanna see if i can get 4 big ones, surround the router bit and use it as a dust collection system... i know i could make a hood but i'd just liek to try this idea :)
loc-line has 3/4 inch.. that might work
shop-vacs work well
yea, but i can't get it in close enough
just make a bracket to hold the rigid part of the nozzle
and i want it to surround it
and you only need one ;)
i don't think it does a good enough job, i want to see if this other setup might be better
maybe i should try my big shop vac first... but i dunno
it's the nozzle that makes the difference
but my experience has been in evacuating small amounts of plastic, not large amounts of sawdust
yea, one that attempts to suck in the general direction?
the thin flat ones were good
higher air speed so things get picked up fron a longer distance
yea, well i'd like it to work for anything... but sawdust is what bugs me, my shop is covered with it... plastic just falls around the machine
yea, maybe i'll try the flat one with the bigger shop vac... maybe that'll be enough
i just thought that those coolant nozzles would be nice, highly adjustable
they're relatively small and they have a lot of ridges inside
those loc-line's are pretty resonably priced too
the size is bad since they're likely to get clogged
yea, well thats why i was gonna use 4 eheh
the ridges reduce vacuum efficiency because they create turbulence in the hose
ok, i'll try the shop vac first :)
I'm not sure it won't work, but I'd try the shop-vac first :)
skunkworks, I would split current so the comparator only sees what it should, R16 C19 and the pot should have their own trace to the point on the sense R
pcw: Pete, what Hall sensors are you using?
I'm trying to find an SY-10, I think it must be a hall effect current sensor
Allegro something or other in SO8
Yes and up to 30A
What does a SY-10 look like?
the ones I'm using must mostly be a current transformer, maybe I should take a hammer to one and see
it's a green rectangular lump
about 1" square by 1/2"
* pcw googles green rectangular lump
might as well, sy-10 doesn't bring anything up
Sounds like some Halls Ive seen
how many leads??
No hint of manufacturer?
I've got to take the drive apart again
* eric_unterhausen with screwdriver in hand
this may help: Nana electronics
didn't help much
tells me I'm right it's a current sensor, 4 logic pins and 2 current pins
green lump: http://cgi.ebay.com/LOT-QTY-3-NEW-HALL-CURRENT-SENSORS-SY-25-NANA-LEM_W0QQitemZ190252877159QQcmdZViewItemQQptZBI_Automation_Components?_trksid=p3286.m20.l1116
how your iterface going ?
well is working fine , many new features added
I guess I should have looked at the weather before I waxed my son's snowboard, heatwave out there
skunkworks, er are my eye deceiving me or are the sense pins shorted by the blue area
* archivist not used to eagle at all
contrast sux a bit I can see the clearance just
should not be.
that ground plane is jsut for the reference and comparator.
ew interesting list question Replacing Mach 3 by EMC? Performace?
the naive cam detector (G64 Ptolerance) might fix his naive cam output
(but I have no clue what mach does)
I am an expert.. - it runs on microsofts operating system and has a screen editor.
should be simple for him to try out, or should one of us try his gcode
he doesn't even have to hook it to the machine to see if it runs better
skunkworks_: true, but he would have to set G64P as well as configure his real velocity and acceleration
that would have to be part of the reply
the g64px.xxx really does work nice.
[21:33:13] <skunkworks_> http://www.cnczone.com/forums/showthread.php?t=72141
somewhat miss informed
* archivist awaits a samco reply
archivist u want this touch screen display? I cant find anyone to give it to!
what touch screen :)
pjm_, did you hear that Im actually running one now with a pc in its rear
skunkworks_, you take the Mach3 replacement, I'll take the RT kernel :)
archivist ahh nice, thats what i need
SWPadnos: deal. :)
not that this fires up properly each time
i just upgraded my emc2 box to a 2.4G p4 and its running very nicely indeed
this has a P4 in the rear
room for two pci and has parport, just the job
darn.. I would _never_ have expected that Mach is really _that_ bad
had to use a plasma with Mach today
that stuff is horrible
I got it to crap out repeatedly by loading one program
every time I loaded it, it "segfaulted" or whatever the windows term is
and the fun part is that I had a similar program only offseted in Y with 30 mm, which worked right
archivist: not quite bsod
windows was fine, only mach has performed an illegal operation, and needs to shut down
hats no good for machine control
alex_joni: why yuo use mach ?
someone call the police!
micges: not my machine
oh, I didn't mention that after that I had to start/stop it at least 2-3 times till the preview would show anything again
but surely you are legally responsible for the illegal operation it performed under your control
(the preview which doesn't show the current tool location btw..)
useless crap.. don't want to blame mach for that, as I understand it might be the screen designer who did that
cradek: thank god for AXIS and program extents (with proper numbers on them)
alex_joni: no, thank jeff ;-)
nope, that one's my fault
seb_kuzminsky: some might say they have common ancestors :)
yeah, it was cradek to be blamed for that
my favorite features are the ones I wrote. my favorite code is the stuff jepler wrote.
in two days experience with Mach, I only had it freeze once
that's, uh, good
looked like a hard RT freeze, vertical lines on the screen, not even a BSOD from windows
oh, and the machine ran away
* seb_kuzminsky coughs
Results 1 - 10 of about 104,000 for mach3 freeze.
cradek: I was astonished
good things steppers can't get anywhere very fast :-)
it also happened when "Mach performed an illegal operation"
this is a plasma gantry (about 2.5m wide)
alex_joni: did it at least leave the plasma torch on while running away? ;-)
but the sheet ran out, and the flame was cut
(luckily the plasma unit is smart enough :D)
hooray for hardware
nothing like fail-safe hardware
seb_kuzminsky: not quite failsafe, but anyways
wonder if the charge pump output stays on when it freezes and runs away. obvoiusly the pulse generating doohicky is still going.
I wouldn't be surprised if it did
it only ran for so much
maybe a meter
oh only a meter, that's ok then
I mean, it didn't reach the end of travel :D
was anyone standing in the space
seb_kuzminsky: plasma cutting is lots more tolerant against errors like this
archivist: surely not :)
if it didnt run the lit torch off the screw it's not that bit a deal
lit torch doesn't stay on more than 3-4 seconds
it's ok up to 1second if you touch it :D
you must have some chuck norris genes for that though
had a coworker happen that to him
stick his hand under the torch to check air flow
just as it ignited the arc
(that was a couple years ago though.. not Mach's fault :)
* alex_joni pets his robots
asimov is turning in his grave
hmm.. maybe Karel Capek
my coworker put hand into laser to check if its on
it was on
cauterizes while it cuts (tm)
10kv does as well alex_joni
micges: although I think for laser it's less dangerous if you get a different focal length
* archivist knows
depending on the laser power though..
can't escape 10kW :D
most I had my hand on was 6kW laser
1.5 kw it was
I had an arc to my finger from the boost diode in a colour tv which was about 10kv pulsed interesting small hole that didnt bleed till a week later
[22:05:16] <alex_joni> http://www.cloos.de/img/Chronik/1978.jpg
archivist: ouch :D
the most fun I have with robots is using the tactile sensor
waterjet shoot in my boss' face
you apply a 60V (or 700V) voltage on the gas nozzle, and go slowly towards the workpiece
alex_joni, hardly hurt
glad it was small pressure he has only scare
archivist: no, but touching it with one hand, and touching ground with the other is nicely refreshing :D
especially around 700V
luckily it's only a couple microAmps
so it's safe
as long as you're not scared of touching ground
if you do it boldly, it's no issue
most of my shocks have been 240v ac mains
if you're afraid, then it hurts.. as it starts to arc
this is 700V DC
it's made to sense the workpiece through rust and whatnot
anyone used smart material probe of emc ? G38.x ?
how can I increase precision of probing ?
lower the speed and/or increase encoder resolution
yes those are the only ways
also, good servo tuning I suppose
or get a 5i20 and write a position latching module that gets triggered from an input
hm2 has that - latch-on-index
if you move one encoder count per servo cycle, you will have the maximum possible resolution
seb_kuzminsky, can it altch-on-something-other-than-index?
(probe input is checked on the servo cycle)
there's room in the quadcounter firmware module for it, but i dont think there's any actual firmwares that use anything other than the index pin, and the driver doesnt support it yet
nor the motion controller
it would be nontrivial
(and it gains you nothing, except being able to move faster while probing)
cradek: to get the probed position from soemthing other than the axis feedback position?
best to not swing an expensive probe around too fast anyway :-)
without thinking it through, I'm not sure how many layers would have to be touched
I have build into axis material scanning but when I'm running it with F100 that takes to much time
cradek: just spit the positions to dmesg from the driver
and be done with it :D
cradek: surely we can find a safe speed higher than one encoder edge per servo cycle? there's *some* travel in the probe no doubt
let the user worry about units and offsets and whatnot :D
seb_kuzminsky: some are even analog
so you go to one position and read the probe trip value
analog! how quaint! ;-)
seb_kuzminsky: I didn't mean that's the highest safe speed; it's what you have to do currently to get full precision
some "probe's" are basicly a laser distance meter
weekend is starting!
happy weekend cradek :-)
hmm.. ubuntu 8.04.2 was released today
~200 updates from 8.04.1
Just this once .. here's the log: http://www.linuxcnc.org/irc/irc.freenode.net:6667/emc/2009-01-23.txt
[22:39:52] <alex_joni> http://www.theregister.co.uk/2009/01/23/us_navy_r2_d2_lasers/
hahaha Labeling something "CVS done right" is about the same as labeling something "a urinary tract infection done right..
(that's about SVN)
alex_joni: by linus torvalds no doubt
jepler: might be :)
good night all
any pico-servo users around?
people may not need to be a user to answer the real question
on irc it's continued polite to simply ask your actual question, no need to ask whether it's OK to ask your question
er, "considered", not "continued"
yes - I'm familiar with irc. that was just a polite 'is anybody actually here'? before asking
I'm trying to work towards the simplest thing that will actually work, in order of pieces needed. And I'm wondering about the benefits of the pico controller & servo amps over gecko drives. It adds $250 to the minimal get something working cost
for emc, we generally consider "step-servos" to be inferior to the systems like pico and mesa (http://mesanet.com)
which close the loop inside the PC
with these systems, you don't have to worry about limited step rates, and the PC is continuously monitoring the motor position compared to the commanded position
(so for instance you tune by setting numbers in a configuration, not by twisting pots; and you can use tools like halscope to look at the motor's response to a command, rather than going by eye or requiring a physical oscilloscope to monitor an error output)
(but I've never actually used a step-servo system like gecko, so I don't really know what that end of the spectrum is like)
and of course the pico-systems PWM servo amplifier's spec is 160V/20A, twice the power of a 80V/20A G340