[02:25:24] <Skullworks> http://www.dailymail.co.uk/sciencetech/article-1167004/Adam-robot-make-scientific-discovery-conducting-OWN-experiments.html
I am trying to install emc2 / ubuntu 8.04 live cd and would not let me partition, during interactive install, no erro msg. show s up
how much ram is in your system?
did you run the media test on the cd at the first menu?
maybe his hard disk controller isn't being detected
512 mb ddr
no dit not run media test
ok, that is enough
run the media test - it's very easy to get a bad cd burn
mih, good idea to test the cd, and, need more info on 'would not let me partition', what did you see?
ok , however Im am booted on the livecd
that's good but is not a substitute for the media check
can I mediacheck within ubuntu?
Optic: fdisk -l shows nothing, does this mean hd is not detected?
i would imagine
but it doesn't hurt to do the test
check dmesg output and see if it got your controller
is your hard disk weird at all?
no errors found for integrity check
this is min
this is mih
what kind of disk is it?
(IDE, SCSI, SATA ...)
ok, that should be detected, unless the controller is weird
what's the motherboard chipset?
msi neo2 platinum [ nvidia ]
mih have you ever installed linux on this system before?
I had ubuntu 8
sometimes you'll have two IDE disks with the same master/slave flag; windows will happily use it but linux complains
I will remove the slave hd
you can install EMC2 and the realtime kernel onto an already installed 8.04 system
you don't need the liveCD
[04:22:39] <SWPadnos> http://wiki.linuxcnc.org/cgi-bin/emcinfo.pl?Installing_EMC2#On_Ubuntu_8_04_using_precompiled_EMC2_packages
I don't know what I have now, it won't boot by itself
if you can't get our liveCD to work, please try a stock Ubuntu 8.04 CD and let us know if that works
can you give me the link again my chat window froze
[04:26:28] <SWPadnos> http://wiki.linuxcnc.org/cgi-bin/emcinfo.pl?Installing_EMC2#On_Ubuntu_8_04_using_precompiled_EMC2_packages
if you can't get our liveCD to work, please try a stock Ubuntu 8.04 CD and let us know if that works
was that freeze on the EMC machine or another?
md5 the iso and burn at 4x speed
stock live cd works
could you make a wiki page and stick the output of dmesg on it?
and maybe lspci
(upload the files and link to them if you could)
[04:29:23] <JymmmEMC> http://codepad.org
there have been a couple of reports like this, but I don't think we have a list of hardware that the problem crops up on
no, the wiki is a better place for this I think :)
but ide is ide, unless it's an onboard RAID or something
"EMC2 CD didn't work on this hardware, 8.04 CD did" ...
some of those have been problematic for Linux in general
[04:31:26] <JymmmEMC> http://www.metacafe.com/watch/2696469/hyundai_aggressive_marketing_against_big_3/
SWPadnos: did you see my Q about simple/cheap 2 or 3 I/O via ethernet?
yep, nothing came to mind, especially in the tax bracket I expect you're looking for ;)
I would try on an old compaq wity 256 ram would be enough for emc2?
I think you need at least 256, prefereably 512 for the install
you can run with 256
SWPadnos: Yep $20 or less =)
I know where you can get connectors for that price
SWPadnos: me too, your junk box
better pricing too FREE!
sure, I'll sell you some 10/100 connectors at $20 each
I got those
damn. and I was getting excited about the profit potential
Yeah, go ahead and take out a 3rd on your house for that
no no no, I'm the one who *gets* the revenue
SWPadnos: Sure, tell the bank that
is there description of boot live cd image from usb thumb? ( wiki describes cf via ide )
SWPadnos: RFC2324 and RFC 2325
tomp: It works good
just copy cd contents to thumb?
tomp, Les Newell made a CF turotial, and there's been success with USB sticks with a tutorial on PenDriveLinux.com (I think)
ok, pendrivelinux hello :)
Not anywhere close actually
also, there's an application in Jaunty (probably in 8.xx also, via backports) which will install an ISO onto a USB drive
ought be a start... Install Ubuntu 8.10 to a Flash Drive using the Live CD http://www.pendrivelinux.com/ubuntu-810-install-using-the-built-in-usb-installer/
dang, does ubuntu 8.04 have a 'System > Administration > Create a USB startup disk:' menu item? ( on w$ now )
no, I think it was added in 8.10
but it's possible that it's available in backports (you have to enable that explicitly in Synaptic)
ok, rebooting, thx
Heh, he could have just used the VM I created! lol
nope - oh well :)
oh hey, I downloaded the P2V migration tool from VMWare
we'll see how well it works
physical to virtual
have you used it at all?
I'm planning on it, but I heard that it might catch EVERYTHING
I was wondering how that was bad :)
I need the disk space before I can try it out
What I need is a damn NAS box
yep. I've got to get my other workstation somewhere useful
I'm also maxed out the hdd in the MBP, so I need to crack the sucker open again and installed a larger hdd
what's in it now?
ah, relatively small
iso's and VM's take up a LOT of room
same as this workstation though ;)
SWPadnos: Oh, I just found out about MFS, I want to check it out and might play around
what is it?
a redundant network distributed FS
fault tolerant too
don't tell me Moose Peterson made a photo file system or something
Though, I'm not sure I'm like the MASTER's needs
ok, similar to a persistent torrent, complete with master tracker
But FUSE can run over SSL
Ubuntu USB desktop image creator?
my Jaunty machine is off, so I can't check there
note that the version in backports likely has a bug which may cause it to make a non-bootable stick
you might have to put syslinus there yourself, and/or make the partition bootable
Oh hell, nm on the MFS... it's gpl
well it installed to 8.04 ok ( orig from live cd ) now, where to find a live cd, maybe just grab iso and mount it? no. rtfm!
GPL isn't all that bad, unless you want to change it and not distribute the code
eh? dangerous app? makes brick sticks?
no need to mount, you point the program at a bootable ISO :)
SWPadnos: I've never really cared for gpl
no, forgets to put syslinux on the stick, and forgets to mark the partition bootable
JymmmEMC, and yet you use GPL all over the place (like the freenode server software ...)
SWPadnos: ok, will try (maybe not this stick tho), i could even repair the boot flag & push syslinux onto it in a pinch
yeah. there's a thread I was reading about this just today
I think I was searching for how to update a USB stick install
which doesn't work all that well, I'll have you know
(at least not when I do it ;) )
yeah, tried that
but did you make a LIVEUSB or persistant?
problem is that the casper-rw "partition" fills up
live and persistent
well you need a big enough stick
there's a loopback disk image, which I made 512M
the stick is 2G
yeah, so? try 4gb
there's extra stuff that gets stored, and I stopped messing with it before figuring it out
I think it doesn't modify the original image, it adds all the extra stuff to the writable partition, overlaid on the boot image
I removed second hd and set the the remaining one to master, it was a priority conflict , and the partitioning program works now
[05:05:16] <SkinnYPuP> http://www.pendrivelinux.com/
yes, they talk about the loopback vs separate casper partition schmes http://www.pendrivelinux.com/ubuntu-810-persistent-flash-drive-install-from-live-cd/
oh gnite SWPadnos, thx
[05:07:35] <SkinnYPuP> http://www.pendrivelinux.com/tag/usb-ubuntu-804/
I recall when messin with an 810 live disk there was an install to usb in the admin menu
maybe there's something to be learned from its script if anyone is interested in looking
back to w$ for cad, thx
is it recomanded to update ubuntu 8.04 + EMC2?
SWPadnos_ is now known as SWPadnos
[Global Notice] Good morning, it would appear we're experiencing some connectivity issues this morning. We're looking into it. Apologies for the inconvenience and have a good day!
JymmmEMC: one thing that comes to mind is serial over eth
there are some cheapish adapters
and you can use DTS/DTR as I/O
alex_joni: not a bad idea... just to turn on coffee maker and to check it's level
there is some RFC for serial over eth
I use ser2net on linux
that does the serial<->eth conversion
it's just a toy, been thinking about it for 8 years and counting =)
JustinXJS2_ is now known as JustinXJS2
Can anybody tell me how to debug emc?
there should be a debugmode page in the wiki i think
Guest667: emc is pretty big
what aspects do you want to debug?
i want to study the source code,i have read it for some time,but always confused about the source structures
Guest667: there is a developers manual
it contains a tiny bit of how emc2 is set up
I am a newbie for linux develop,but i pay attention for EMC for a long times
i have download a liveCD,and build it following the suggestions successfully
but i still donot know how to debug the source code ,if i make any change on the code,
the project contains so many modules,how can the develops debug the multi sources project?
usually with patience
nobody here but us chickens
I'm not even a chicken
haha. another great Spam subject line: "You will have so much meat - it will be enough for a couple of servings"
I think that's more amusing that "your little friend will grow without limits"
I'm about ready to change my e mail address spam outnumbers messages 2 to 1
yep. I think it
it's about the same here
Im happy with gmail
Mozilla seems to be able to detect it OK though, so I could turn on the auto-delete function
every time I change I go 18 to 24 months spam free
thunderbird does a great job.
or turn on the spam controls at my ISP
Pegasus catches it good but it is still annoying
I've learned a few thinsg about multi-selection on Windows though :)
well, you know how sift-click selects a range and ctrl-click adds individual elements to the selection?
well, ctrl-shift-click adds the range from the last element you ctrl-clicked on
so you can do multiple ranges with click / shift-click / ctrl-click (somewhere else) / ctrl-shift-click
I actually understood what you said :)
wow. and that's before I've had any coffee :)
is there an invert like ^A, pick everything except whats been selected?
maybe you had mine
I'm on my last cup
ctrl-A is select all usually
well i can always ^A then remove the odd things, i thought id select the odd things and invert the set
oh interesting. In Mozilla, ctrl-shift-A is "select thread"
that works better when you don't have 9000 other messages in your inbox
* BJT-Work likes the verify button on mc it just saved me from cutting a large divot in the part
I wish we could load the material shape into EMC :)
nerf steel? ( virtual stock) ?
all you have to do is change vismach to show the part, and also incorporate gdepth to show what's been machined away
just a "small" hack!
yep. oh, coffee's ready. see you later :)
the maxwell house coffee jingle http://www.roadode.com/classicwmv1/maxwellhouse.wmv
* BJT-Work wishes he knew how to run vismach
BJT-Work, Ive run it, but modding it is.......
I've only heard tell of it but not seen it :)
several of the sample configs run it
I'll have to look when I get home, no linux here :(
you just have to run them...
what, are you on a desert island or something?
I dont get the python code yet though
4 computers in the machine shop 3 windoz and 1 dos
sounds similar to your spam problem
as soon as there is a linux program to replace sw I'm on it :)
actually, SolidWorks seems to work quite well in a VM
2004 I think
the one (?) that had the ratcheting screwdriver as one of the sample designs
2009 here and what a pain to install it has to connect to the mother ship and get permission...
I could spin the model around in realtime in a non-fullscreen VM
the splash screens change each time you boot up...
this was on a dual Opteron with an Nvidia Quadro FX3500
both slower than a $500-1000 machine today
* BJT-Work wanders back to the mill to make chips
SWPadnos tried using solidcam with solidworks with EMC?
Valen, no. I don't have SW any more (I only installed it as a test)
evening, btw i have registered a user on the linuxcnc.org site, no confirmation email as yet, how long do they typically take to arrive?
took me a few minutes
ah i registered last night, still nothing
try logging in
yeah i tried that, it said the registration process had not completed
you may have grey listing or something
pjm__: you still around?
[17:56:57] <skunkworks_> http://cgi.ebay.com/Nice-KEARNEY-TRECKER-HORIZONTAL-CNC-MACHINING-CENTER_W0QQitemZ170313337132QQcmdZViewItemQQptZBI_Mills?hash=item170313337132&_trksid=p3286.c0.m14&_trkparms=72%3A1205%7C66%3A2%7C65%3A12%7C39%3A1%7C240%3A1318%7C301%3A0%7C293%3A1%7C294%3A50
nice tou to put EMC on
vista green is ugly
who cares about the colour!
I like how the tools are covered so you can't confuse it
(I assume it doesn't put them back where it got them)
there are no tools in the tool changer..
do they point inwards :)
[18:11:56] <skunkworks_> http://www.umtn.com/pics/650273_2.jpg
that's a big machine!
oh forget it, I assumed they pointed down
I would still like one to play with
it is a little brother to ours. :) full 4th axis though
that is one big-ass URL
not your fault :)
did you see the slashdot article about how shortening URLs could save some significant amount of bandwidth?
a couple of weeks ago
url shortening services are evil though
no, not like tinyURL
[18:14:43] <Optic> http://ebay.com/item/170313337132
that should work!
that's an interesting idea
just not http://short.server.com/PageName?VariableOne=somereallylongpieceofdatasowecantrrackyourhabits&otherdata=moreuselessinformation+thats+not+_related
a lot of people jumped on how the headers are really small compared to content anyway, but when a page has two words that are displayed and 1k of link text behind it, for 20-100 links per page, it gets pretty big
some hide it as post data
pjmcnc, pjm__ : your email addy had a typo in it (ending in .comp instead of .com I assume)
try logging in again, you'll get a new confirmation email
alex_joni, form error zipcode does not allow british postcode
or Canadian postal codes!
leave it blank
I did, typical yank address form though
centre of the universe :}
archivist: complains redirected to google please
archivist: someone else wrote me an email about it, but there's not much I can do about it :/
LawrenceG: were you one of the audience that boo'ed billy bob thortan off the stage? ;)
* archivist has a nose around the map
skunkworks, "I know nothing"
I would have expected less affluent areas to have more users due to low cost, but thats not the case
only rich hobbyists can afford to play with CNC machines
archivist: the map is about 3 days old
that hardly makes it accurate
shows the trend though
alright where is this map
well hidden to the blind
alex_joni, ahh ok thanks for that ;-) its this damn keyboard, it does keep making errorrs
fenn, linuxcnc.org, you have to sign in I think
pjmcnc: I have a couple of keyboards like that
I had to scroll around fenn the look bottom left
* fenn was looking in the mailing list thread for some url
you have to sign in to see it
huh i would have expected more in germany
fenn: 3 days of map
alex_joni thanks for fixing my account, its worked now
huh - mem386 found some bad memory. I think this is the first time I have run into that. (suprisingly)
BJT-Work , u asked if i was around about 2 hours back!
sorry i didnt see it then
that's ok I was just wondering if your log in problems were fixed then I ran into Alex and he fixed it
ahh ok thanks ;-) yeah its working now and I'm on the map
we need some more brits using EMC2 judging by the map
I know of a few more
i'm trying to get the locals i know with mills to move into reality
looks like john_s will convert on lathes at least and that will get a few more
wernt you going to do an MEW article
or was that paragon (not seen for a while)
umm whats a MEW?
i'm trying to acqure an emco lathe
model engineers workshop
the controller has failed on it
ah not me ;-(
there is a guy on here that converted a emco lathe.
they are neat little machines - stepper+ballscrew
I keep getting beat on fleabay trying to get a cheap dead cnc
this thing is two halves with a big hinge, and u can wheel the control unit around
[19:39:37] <skunkworks_> http://www.youtube.com/user/emcboard
[19:41:44] <skunkworks_> http://www.linuxcnc.org/content/view/28/2/lang,en/
there is one of those EMCO's less than a mile from my house and I repaired it for him
emcotronic-T1 this thing is
apparently the price of fixing the controller is more than the machien is worth
-T120 i meant
bloody keyboard again!
BTW - I have one of those atom 330's as a media pc - working great so far.
the one I fixed had a descrete device fail, easy repair
what are you running on it?
[19:47:03] <skunkworks_> http://www.cnczone.com/forums/showpost.php?p=598839&postcount=33
I am running mytheatre.
he's brain dead
archivist do u know a good place to get small 3phase motors? i need a 0.75Kw one to play with
pjm__, define "good" machine mart, the basement here, or fleabay, local scrap yard
hahh ah yes i forgot about machine mart, we have one just up the road
its a chain of expensive machine tools shops in the UK
national chain of stores
mainly crap/cheaper stuff though
kinda like Grizzly I bet
harbor freight? ;)
yep it looks like harbor freight with a funny accent
tools still taste chinese
cradek: do you remember any of the stuff we learned about routing plexiglass? have any idea if you can find that special spiral cutter I bought for it?
yes, cut slow, feed fast, yes I bet I know where it is
that's a problem, since I have no speed control .. it's 20krpm or 0
that little spindle may not have enough power anyway
also, the tool was 1/4 shank I think
oh it was? if so, drat.
or a little soapy water.
plain old flood coolant?
sure could have been
cradek: maybe I'll have to impose on you for this project ..
if the edges don't have to be perfect, score-and-snap works too
no, it has to be shaped
[20:08:06] <cradek> http://www.harveytool.com/products/index.php?page_function=show_family&category_id=1&product_family=Plastic+Cutting+End+Mills
I note the wide variation in rake
this says up to 18,000 rpm, .010 feed "for hard plastic"
so, you want 180 inches/minute (or to slow down the spindle)
what kind of spindle? brushed?
could a cheap and dirty light dimmer be used?
there's no way it would have the power
it's an engraving spindle - little motor with an O-ring belt to the spindle
.010 chunks of even thin plexi take a little power to peel off
iirc, the real problem is holding the plexi down without damaging it
* skunkworks_ whistles a tune about vaccum chucks..
rake pulls it up :)
is it covered on both sides? then I would pull the carpet tape trick.
tape on the blue protective film?
I have used some tape before - it's very hard to peel it up without crazing it
and yeah, I had to take off the protective plastic
the blue stuff might not be stuck hard enough. A lot of the pastics we get here have paper mask
yeah I bet that would hold it fine
do they make "sticky note adhesive" in a spray bottle yet?
carpet doublesided tape does not let go
*not contact cement
oh, I know -- determine a bunch of places that the cutter won't go, and put rare earth magnets there to pull it against the table
jepler: there is that liquid plastic they use in magazines
just create a plastic magnet
to hold ads
some gooey stuff, which you can cleanly peel off
so I need to go buy magazine ads?
I think it's called removable glue/adhesive
"removable glue dots" http://www.gluedots.com/display/router.aspx?DocID=1083
but with a bunch of separate dots, it seems like getting it flat on the table is now the problem
The magnet idea was pretty elegant
and whether they'll actually hold the plastic down when you're cutting the plastic out..
jepler: I think it's called rubber cement
[20:37:22] <alex_joni> http://en.wikipedia.org/wiki/Rubber_cement
I know rubber cement, but I think it'll damage plexiglass
Then it's vacuum-table for you...
[20:51:20] <skunkworks_> http://www.electronicsam.com/images/KandT/vactop.JPG
[20:51:30] <skunkworks_> http://www.electronicsam.com/images/KandT/vacback.JPG
I'd shop this job off to skunkworks_ except he'd expect me to do his next circuit board run
heh - I keep trying to find the time to finish up my circuit board mill
skunkworks_: that's pretty nice!
makes it easy to do things like this http://www.electronicsam.com/images/KandT/servostart/top.JPG
That's a nice bit of thick copper trace there
though.. makes it important to spread solder across the heat-island spaces..
you mean thermals?
[21:10:22] <skunkworks_> http://www.electronicsam.com/images/KandT/servostart/DSC_5094.JPG
that is what happens when the vacumm fails - (and notice the thermals are bigger)
I think this is the final solution http://www.electronicsam.com/images/KandT/servostart/schem/latestcurrentlimit/latestboard.png
(atleast it hasn't smoked yet) http://www.electronicsam.com/images/KandT/servostart/schem/latestcurrentlimit/right.JPG
ah... that's the board belonging to that beast
optocoupled and all
where's the 7Watt resistor ?
what do you mean? it is left of Q1
4 leg device
yeah; but in the assembled board ?
Is it the thing I think I see below the big C ?
[21:17:38] <skunkworks_> http://www.electronicsam.com/images/KandT/servostart/amp.JPG
different version - but you can see the 7w resistor
Yes - you can just see the end of it
yeah.. ; how's it connected internally ?
(what's the use behind giving it 4 pins ?)
2 for power - 2 for sensing
Kelvin connection resistor.
so you measure across the resistor not its leads
[21:19:58] <skunkworks_> http://www.ohmite.com/catalog/pdf/10_series.pdf
using pyvcp can you specify a font color?
In Ubuntu 8.04 ... anyone have an idea on how to kill the calandar that resides (on my desktop) in the lower right corner?
It covers up part of the current app.
dave_1, right-click on it and select "remove from panel"
or just click on the date in the panel, that will make the calendar disappear (it's a toggle)
right click does not bring up panel and clicking on the panel just makes it fill screen however it did bring up a tab for it and clicking on that makd it go away. FINALLY
is that the calendar app that's normally at the top right?
(showing the date and time)
Anybody looked into using Powerex intellimod IGBTs for driving brushed DC/Brushless DC/AC motors?
They look pretty sweet, only need logic level inputs to drive three half bridge IGBT modules. About $20-$30 for the whole thing.
have you been hacking on the spi stuff we talked about a while ago?
Well to be honest, my master's research has really picked up and I haven't had a ton of time to do anything with it.
i know how that goes
I do have an extruder heater running.
i'm going to try to get something going at Fest in the end of may
how's your reprap? :-)
probably ... I apparently accidentally hit some keystroke which moves the whole bar. so date/time in in LR at this time. ;-)
I'm only using the raw mode right now though.
you're talking to an spi adc via hm2 raw mode? wow!
Yeah, It wasn't really that bad.
But it could only read the adc every 4ish thread cycles.
not too bad because the thermocouple adc takes 100ms to convert...
"not really that bad", i want that on my tombstone ;-)
the reprap is coming along well, I need to get into the machine shop to make the parts I have been designing.
have you started making a reprap?
no... well yes sort of... my plan is to convert my x2 to cnc, then make a reprap extruder-head for it
i've started the cnc conversion ;-)
can you send me the spi-via-raw code you're using?
Sure, I just wrote a realtime component. I'll send it to you when I get home tonight.
I have an email address for you, but I'm not sure if it is right.
then you hook your rt component up to hm2.raw via hal?
i'm seb "splat" highlab.com
yeah, then a counter inside the rt component to keep track of the current frame to be sent/received. It's very specific to the device.
i'm super excited you got it actually working with an extruder :-)
I could read the adc every cycle if I could send and receive more than one byte / cycle.
(in raw mode)
Well i wish I could say that I have a full extruder right now...just heating a small chuck of aluminum right now.
seems inkscape can do dxf import
* alex_joni just read about that..
geo01005: I am using descrete igbt's and so far I love them :)
Have you ever look into these powerex modules?
You should ask jmkasunich
Here is a link for a data sheet http://www.pwrx.com/pwrx/docs/ps21765.pdf
skunkworks: So the pictures you posted earlier were igbt not fets?
these are what I have
[22:41:00] <skunkworks> http://www.irf.com/product-info/datasheets/data/irg4pf50wd.pdf
You still have to come up with the high side switching supply for that device though right?
yes - IR21844 -
I assume you are using all N channel switches.
that package looks pretty cool
They have some application notes on their website that go though all the power stage design.
I though that I might be able to build a whole driver for about $50.
How does that compare to your discrete design?
I don't know if I know enough to give you an answer ;) It looks like it is just the power stage.. - I had to add blanking / current limits and such (they actually show the turn on spike on thier traces)
The device has built in current limits. However I would think it would be nice to have pwm controller to create a current controlled amp.
I'm not trying to pull anybody into a black hole of driver design, but if you are interested here is a app note.
[22:52:32] <geo01005> http://www.pwrx.com/pwrx/app/dip_ipm_app_note.pdf
This probably isn't the right place to discuss driver design anyway.
I don't mind ;)
I don't understand how they are sensing current limit..
within the module
good night all
Current is sensed as a voltage drop across a shunt resistor, just like your design.
hmm - I guess they really don't show that 'connection' within the package. either that or I just am not seeing it.
Sorry, that data sheet dosn't show the connection, try this one http://www.pwrx.com/pwrx/docs/ps21765.pdf
The connection is external. The data sheets are very brief, the application notes are much, much better.
ah - I see it in the app notes
maybe PCW could tel us if he uses powerex modules in his 8I20?
Just going to say, Fairchild, not powerex though they look almost identical
I swear he has an alarm that goes off when certain keywords are used
DIng Ding Ding!
I have to say I have learned a lot.
I think ;)
PCW: I don't know if you want to say but what model number do you use on the 8i20?
I still have to say my current in to the h-bridge is pretty equal to current out..
I think the Fairchild modules maybe somewhat cheaper
The 30A 600 V one we use is around $19 (and it includes the bootstrap diodes)
That is pretty good.
I have to wonder how many of them I would fry before getting it right.
Current in should be much lower at stall
Weve never blown up our first one, but we have high side OC shutdown
I just want to use one of these modules to drive a treadmill motor. dosn't require all the fancy stuff you have on the 8I20.
"geo01005 secretly wants a 8i20 really bad"
They are a bargain and easy to heatsink compared to discretes
May have a proto or blem if you want to play with one later this year
That would be nice but I would hate to impose.
Would the 8i20 work for driving a brushed DC motor?
Old protos are not much use to use to us
Current firmware is just for 3 phase though
Could I trick it by keeping the hall effect signal static?
probably brush motor support could be added
fairly easlily, just bypass the Clark/Park stuff and
control armature current through one Hall
(Hall here is the Hall device we use for measuring current)
pcw: because of bemf?
sure, so is an encoder usually used for commutation on the 8i20?
or is it sensor-less?
SW: because really hard to measure 3 phase currents accurately with shunt resistors
(no good time during PWM cycle to sample)
I was asking about current in vs current out..
GEO: Normally encoder, we can use HALLs for initial startup
It can also run sensorless, but its really intended for servo
Hmm, very cool. Well i've got to run.
SW: because the motor voltage is lower than the power supply voltage, so for example if you have 20A of motor current with 20% PWM
your power supply will see a peak load of 20A but at a 20% duty cycle = 4A average current
should have said, : you have 20A of "stalled" motor current
huh. I know that my current is correct on the output because 20a = 20ftlbs of torque.
I will have to play some more.. Plus I don't know how good my dc clamp on amp meter is - I could try the ac before the rectifier.
skunkworks: how many volts going to the driver? how many volts going to the motor?
power into driver = input volts * input amps
power into motor = motor volts * motor amps
difference = losses in driver
if the shaft is stalled, power out of motor = 0 (speed times torque, speed = 0)
so power into motor = power dissipated in motor