#emc | Logs for 2009-03-13

[00:32:17] <eric_unterhausen> hello
[00:32:23] <eric_unterhausen> j/k
[00:49:25] <eric_unterhausen> so I decided to build a sim only install of EMC on Ubuntu 8.10 AMD64
[00:49:52] <eric_unterhausen> It built, but the preview in axis fails to work properly
[00:50:30] <eric_unterhausen> mostly you see the background of the window, the preview pane seems to be rendered behind that
[00:50:58] <cradek> make sure desktop effects are disabled
[00:51:10] <eric_unterhausen> that must be it
[00:51:24] <cradek> ubuntu screwed all non-fullscreen opengl applications in the name of progress
[00:51:40] <cradek> fortunately you can disable it
[00:52:50] <cradek> bbl
[00:54:28] <eric_unterhausen> that worked thx
[00:59:17] <eric_unterhausen> all of a sudden one of the things I've been looking at on ebay has been going for a lot more money
[01:06:13] <eric_unterhausen> JymmmEMC: you ever try to track something from DealExtreme?
[01:07:11] <JymmmEMC> eric_unterhausen: why? order tkaing longer than expected?
[01:07:22] <JymmmEMC> did you check your order status?
[01:07:31] <eric_unterhausen> yes, it has left hongkong
[01:07:41] <JymmmEMC> ok, takes about 7 days
[01:08:04] <eric_unterhausen> it seems usps will track it, in the sense they tell you that they delivered it?
[01:08:27] <JymmmEMC> how long has it been since it left HK?
[01:08:37] <eric_unterhausen> 2 days
[01:08:59] <JymmmEMC> lol, ther's a big pond inbetween... give it 7 days
[01:09:09] <JymmmEMC> going to the Us I assume
[01:09:11] <JymmmEMC> US
[01:09:13] <eric_unterhausen> what did they send it on, a piper cub?
[01:09:20] <eric_unterhausen> yes, PA
[01:09:24] <JymmmEMC> boat
[01:09:36] <JymmmEMC> unless you paid for air
[01:09:45] <eric_unterhausen> free shipping is boat?
[01:09:50] <JymmmEMC> yep
[01:10:07] <eric_unterhausen> I would figure it would sit in docs for more than 7 days
[01:10:13] <eric_unterhausen> docks
[01:10:22] <JymmmEMC> Nah, too much crap on docks
[01:10:36] <eric_unterhausen> full of unsold cars
[01:10:38] <JymmmEMC> Might sit in US Customs for a while though, depending on what you ordered
[01:10:45] <eric_unterhausen> leds
[01:11:01] <JymmmEMC> Give it 7 days
[01:11:45] <JymmmEMC> will probably be 5 days, but give em 7
[01:12:14] <JymmmEMC> They are very good about keeping ppl updated and the like.
[01:17:09] <eric_unterhausen> upc code has been removed == free after rebate?
[01:40:34] <jmkasunich> mic6 is much nicer than 6061
[01:40:49] <jmkasunich> the chips break themselves
[01:41:56] <eric_unterhausen> what is mic6?
[01:42:03] <jmkasunich> aluminum alloy
[01:42:14] <jmkasunich> sometimes called jig and tooling plate
[01:43:05] <eric_unterhausen> wonder what series it really is
[01:44:38] <eric_unterhausen> we have machines 6061, 2024, and 7075
[01:45:03] <eric_unterhausen> seems like 2024 and 7075 are not as gummy
[01:45:23] <jmkasunich> yeah, 2024 and 7075 machine nicely too, but they are more expensive
[01:45:26] <eric_unterhausen> 6061 does all sorts of strange things in fatigue
[01:46:09] <jmkasunich> at metal express, 3/4" plate, 12" x 12"
[01:46:14] <jmkasunich> 6061 = $91
[01:46:30] <eric_unterhausen> some grad students were fatiguing some, and they thought something was wrong until I pointed out that they were breaking 6061
[01:46:38] <jmkasunich> mic6 = $80
[01:46:41] <eric_unterhausen> nice
[01:46:45] <cradek> oh really
[01:46:51] <eric_unterhausen> it's flatter too, correct?
[01:46:53] <cradek> that's bizarre
[01:47:03] <jmkasunich> 2024 not in stock (call for quote)
[01:47:24] <jmkasunich> 7075 also not in stock
[01:47:38] <eric_unterhausen> i bet they don't get much call for it
[01:48:00] <eric_unterhausen> the mic6 is nicely finished?
[01:48:07] <jmkasunich> yes
[01:48:22] <eric_unterhausen> we have some
[01:48:37] <eric_unterhausen> at least we have something called "tooling plate"
[01:49:20] <jmkasunich> I believe that's the stuff
[01:49:50] <eric_unterhausen> cradek: did you say that about fatigue, or aluminum pricing?
[01:50:01] <cradek> price
[01:50:10] <eric_unterhausen> that does seem strange
[01:50:26] <jmkasunich> yeah, I didn't expect it to be less than 6061, expected about the same
[01:50:32] <eric_unterhausen> there is probably a reason for it though
[01:50:33] <jmkasunich> with 2024 and 7075 quite a bit more
[01:50:49] <eric_unterhausen> 6061 isn't usually that cheap
[01:51:13] <jmkasunich> ok, 6061 _plate_ was $91
[01:51:15] <eric_unterhausen> cheap stuff is 5053 or somesuch
[01:51:26] <jmkasunich> but 6061 extruded, 3/4 x 12 x 12" long, is $55
[01:55:11] <eric_unterhausen> mic6 from mcmaster is cheaper
[01:58:31] <jmkasunich> as long as you want the sizes they sell
[01:58:44] <eric_unterhausen> they have the size you bought
[01:58:46] <jmkasunich> I just used 12 x 12 as an example
[01:58:57] <jmkasunich> the pieces I bought are 3.5 x 3.25 x 1.25 thick
[01:58:58] <eric_unterhausen> nvm then
[01:59:54] <jmkasunich> it is good to remember mcmaster tho - they usually _are_ cheaper if you can use their stock sizes
[02:01:51] <jmkasunich> * jmkasunich debates: start the next operation, or get a decent night's sleep for a change
[02:02:06] <eric_unterhausen> I always do neither
[03:43:57] <JymmmEMC> jmkasunich: sleep tonight, then you'll have the weekend to work
[04:05:19] <Johnash> anyone up for a question?
[04:05:59] <eric_unterhausen> try it
[04:06:06] <Johnash> Question: I have just installed ubuntu 8.04 i386 version, and also installed emc via "emc2-install.sh" method.
[04:06:06] <Johnash> Everything seemed to load, but when I select the rtai app (2.6.24-16-rtai) from boot menu - the screen turns white and comp locks up.
[04:06:06] <Johnash> The Generic kernal (2.6.24-23-generic) works fine. Cannot run EMC without the real time kernal.
[04:06:07] <Johnash> Any suggestions?
[04:08:19] <eric_unterhausen> does ctrl-alt-backspace get you to a command prompt?
[04:10:02] <Johnash> nope - it just kicked me out to the login screen. lol
[04:10:20] <eric_unterhausen> so the comp was not locked up then
[04:10:41] <eric_unterhausen> sorry, it shouldn't let you log in
[04:11:00] <Johnash> did you mean to try this when I load the real time kernal?
[04:11:06] <eric_unterhausen> yes
[04:11:19] <eric_unterhausen> when you get the white screen
[04:11:20] <Johnash> what should it do>?and why?
[04:11:31] <eric_unterhausen> you seem to have an x problem
[04:11:47] <Johnash> x problem?
[04:12:03] <eric_unterhausen> X11, the graphics system for linux
[04:12:51] <Johnash> I was talking to archivist yesterday - he said that I needed to put emc into simulator mode.??
[04:13:06] <eric_unterhausen> that's not going to help you run a machine
[04:13:35] <Johnash> you see - emc loaded- but It wont let me run it without the real time kernal loaded
[04:14:17] <Johnash> but I do not have it hooked up to a machine - and no IO or moton control boards inj comp yet either
[04:14:59] <eric_unterhausen> if you just want to learn about running emc, then sim is good enough
[04:15:09] <eric_unterhausen> you select a sim config from the menu
[04:15:29] <Johnash> so your saying I can just run emc with th ereal time kernal without anything hooked up - just a com?
[04:15:45] <Johnash> i cannot getthe sim menu
[04:15:53] <eric_unterhausen> you can run a stepper machine config in real time without a machine
[04:16:17] <Johnash> when I try to start emc from app menu - it says it needs the rtai loaded
[04:18:57] <eric_unterhausen> emc ../configs/sim/axis.ini
[04:19:08] <eric_unterhausen> no, that doesn't work
[04:20:31] <eric_unterhausen> let's go back to the rtai kernel, when you boot that, get white screen, hit ctrl-alt-backspace, can you log in?
[04:20:51] <eric_unterhausen> or does the computer reboot?
[04:21:52] <Johnash> I havent tryed that - I talking to you from the computer now. Can you give me a few minutes and i'll be back?
[04:22:07] <eric_unterhausen> sure
[04:22:32] <Johnash> if it does give me a login - then i should be fine correct?
[04:22:48] <eric_unterhausen> no, you need to manually reconfigure x
[04:23:10] <eric_unterhausen> there is a program that does it, you have to hit enter a batch of times
[04:23:54] <Johnash> so hit enter a buch of times - if i get loged in?
[04:24:00] <Johnash> bunch
[04:24:18] <eric_unterhausen> dpkg-reconfigure xserver-xorg
[04:24:22] <eric_unterhausen> then hit enter
[04:24:52] <Johnash> thats it
[04:25:13] <eric_unterhausen> it doesn't hurt anything afaik
[04:25:31] <eric_unterhausen> sudo dpkg-reconfigure xserver-xorg
[04:26:47] <Johnash> thanks ill try that
[13:12:53] <Optic> hello linuxcnc
[13:15:55] <Guest793> How goes the homing?
[13:16:05] <Guest793> Guest793 is now known as skunkworks_
[13:16:17] <Optic> didn't get a chance to work on it last night
[13:16:23] <Optic> but this weekend, it will home :)
[13:18:42] <Optic> we also need to calibrate the steps-per-inch
[13:22:42] <Optic> we're finishing up the firmware in the controller too... amplifier enable, charge pump, e-stop
[13:36:17] <JymmmEMC> JymmmEMC is now known as Red70sShow
[13:36:36] <Red70sShow> Red70sShow is now known as JymmmEMC
[14:41:32] <fenn_> fenn_ is now known as fenn
[14:47:56] <JymmmEMC> JymmmEMC is now known as MrAsshole
[14:48:25] <MrAsshole> MrAsshole is now known as JymmmEMC
[18:46:56] <jedediah_> does anyone feel like answering some possibly dumb gcode questions?
[18:48:57] <SWPadnos> you could ask them and find out for sure :)
[18:49:23] <jedediah_> how are non-circular curves typically transformed into gcode arcs?
[18:49:35] <SWPadnos> with CAM software
[18:49:44] <skunkworks_> short line segments
[18:49:48] <jedediah_> I mean mathematically
[18:49:51] <SWPadnos> oh
[18:49:55] <skunkworks_> heh
[18:50:20] <SWPadnos> jepler wrote a program that uses biarcs to segment splines (I think)
[18:50:30] <SWPadnos> I'm not sure where it is, but that could be a starting point
[18:50:40] <jedediah_> the python one? yeah I'm looking at that
[18:52:24] <SWPadnos> this seems to be more of a math question though :)
[18:53:06] <jedediah_> was this used? http://linkinghub.elsevier.com/retrieve/pii/S001044850400003X
[18:53:16] <SWPadnos> no idea
[18:54:48] <archivist> there is some stuff in ttt the truetype tracer as well that cuts a spline to small segments
[19:09:29] <the_goat> gentlmen, would it be bad form to make a torrent of the ubuntu606+emc iso? Mostly for my own convenience, but I will of course understand if you want to keep a handle on downloads
[19:09:47] <SWPadnos> torrent away if you like
[19:09:54] <SWPadnos> as far as I'm concerned
[19:10:04] <the_goat> thank you sir
[19:10:10] <the_goat> we are liking the software up in Toronto ;)
[19:10:21] <SWPadnos> cool
[19:10:39] <the_goat> brilliant idea on making a live CD with an install option, by the way
[19:10:54] <SWPadnos> note that the bandwidth we have available is pretty high, in the 10TB/month range, so don't feel like you need a tracker to ease the load on our hosting
[19:11:07] <SWPadnos> that said, go ahead anyway :)
[19:11:35] <the_goat> cool; I was more concerned about horning in on someone else's ability to control their software distribution... ya know, throw off yer hit counters ;)
[19:11:49] <SWPadnos> heh
[19:12:04] <SWPadnos> one day I'll figure out how to read those HTML logs ;)
[19:12:44] <the_goat> apolgies btw to anyone who is a madam and not a sir; that was presumptuous of me! :)
[19:12:56] <SWPadnos> you insensitive clod!
[19:13:14] <the_goat> * the_goat stumbles into the only all-female linux cnc channel
[19:14:07] <SWPadnos> that sounds fun
[19:14:27] <SWPadnos> I'd have to send my wife in though
[19:14:37] <SWPadnos> (and she's not interested)
[19:24:10] <skunkworks_> http://i177.photobucket.com/albums/w231/Spruft/P1010039-1.jpg
[19:24:38] <skunkworks_> http://elektronikforumet.com/forum/viewtopic.php?f=5&t=18483&start=330
[19:28:51] <the_goat> ser god
[21:14:55] <dareposte> anybody using the 5i20 board from mesa?
[21:15:10] <dareposte> i seem to remember a few people were
[21:15:37] <skunkworks_> A few people here.. cradek for sure
[21:15:49] <skunkworks_> Mine is still in the anti-static bag
[21:18:01] <dareposte> i was curious what they are using for the 50 pin connectors, or where they are sourcing the parts
[21:18:24] <dareposte> a 50 pin multiconductor cable is a bit of a beast
[21:19:06] <dareposte> so i'm guessing its customary to run the cable to an auxiliary panel, and terminate it there as needed
[21:19:18] <dareposte> instead of running everything into the PC
[21:20:08] <SWPadnos> digikey has connectors
[21:20:31] <SWPadnos> breakouts are a pain - they're way more expensive than it seems they should be
[21:21:00] <SWPadnos> there's a company that sells them for around $35 each I think, but I don't remember the name
[21:21:29] <SWPadnos> I think the next higher price is in the $100 range, from Phoenix Contact or Weidmuller or the like
[21:21:32] <dareposte> eh
[21:21:45] <dareposte> well a terminal strip would work just as well
[21:22:10] <dareposte> just curious what's been done
[21:22:12] <SWPadnos> sure, now to find a terminal strip, a 50-pin cable/connector, and a PCB, and to wire it all up ...
[21:22:35] <dareposte> do you have a mesa board?
[21:22:42] <SWPadnos> PCB-mount screw terminals are actually $0.50 or so each
[21:22:46] <SWPadnos> I have several ;)
[21:23:02] <dareposte> i was thinking a din rail mount stacked terminal
[21:23:14] <SWPadnos> I also have opto-22 boards that can connect to them, and a number of DIN rail mount breakouts
[21:23:35] <SWPadnos> I don't recall if the $35 boards are DIN-mount
[21:23:42] <SWPadnos> the Phoenix and Weidmuller ones are
[21:24:02] <dareposte> it seems like it would be pretty necessary, just to avoid having to splice and run a mess of tangled wires
[21:24:14] <SWPadnos> Mesa also sells -T versions of a few of their daughtercards, which have terminal strip headers on them instead of pin headers
[21:24:19] <SWPadnos> they also sell the mating connectors
[21:24:24] <SWPadnos> yes, I agree
[21:24:36] <SWPadnos> it's not only reliability, it's also time
[21:25:08] <SWPadnos> soldering 100 or 150 connections per board (unless you just hand the terminals off a cable) is a nightmare
[21:25:20] <dareposte> i was thinking something like this: http://web6.automationdirect.com/adc/Shopping/Catalog/Terminal_Blocks/Standard_DIN-Rail_Terminal_Blocks_(order_by_Block_Type)/Mini_Terminal_Blocks_-a-_Accessories/10_AWG_(EURO_4-z-15)/DN-M10B
[21:25:28] <SWPadnos> that's per connector actually, on the breakout board
[21:26:18] <SWPadnos> well, you could do that, but you'll have a really bad time of it if you use a flat 50-pin cable to go to one side
[21:26:28] <dareposte> you think?
[21:26:41] <dareposte> what about shielding for the 50 pins
[21:26:42] <SWPadnos> there are 2-stack terminal blocks as well, which may be better in this application (only marginally though)
[21:26:47] <dareposte> yeah
[21:26:53] <dareposte> its probably worth it for a breakout board
[21:27:13] <SWPadnos> you shouldn't need it, if you use twisted pair cable ($$$)
[21:27:16] <dareposte> i like soldering though :)
[21:27:47] <dareposte> i've used some 40-pin cable that is sort of rolled up in shielding like a burrito, then the whole burrito is shielded with a coax-type braid
[21:27:52] <SWPadnos> ah: http://www.winfordeng.com/products/brk2x25.php
[21:28:07] <dareposte> oh that is glorious
[21:28:26] <SWPadnos> you can get the Phoenix or Weidmuller ones on eBay from time to time as well
[21:28:35] <SWPadnos> in the $15-35 range
[21:28:43] <dareposte> sounds good
[21:28:45] <SWPadnos> which are DIN mount
[21:29:04] <dareposte> so you run the 50 pin out of the PC and into a satellite box with the drives / IO / etc
[21:29:18] <SWPadnos> uh - sort of
[21:29:36] <SWPadnos> I don't have a CNC set up here yet, though I have used the 5i22 in a commercial project
[21:29:39] <dareposte> terminate it in that breakout board, and point to point wire in the panel
[21:29:56] <SWPadnos> sure, except that you probably need level shifting and/or optoisolation
[21:29:58] <dareposte> probably put the VFD outside the box to keep it from getting too noisy
[21:30:15] <SWPadnos> so you'd use a 7i37 for that (the 16-in/8-out I/O board)
[21:30:15] <dareposte> yeah
[21:30:30] <dareposte> i have a bunch of optoisolaters
[21:30:39] <SWPadnos> which means you can spend the extra $30 on the 7i37-T and terminal strips, and not deal with an extra 50-pin cable
[21:30:42] <SWPadnos> what kind?
[21:30:51] <dareposte> got a bag of a few hundred
[21:31:02] <dareposte> don't remember, but i'm using them on my current setup and htey work well
[21:31:08] <SWPadnos> ICs or something like an OPTO-22 module?
[21:31:11] <dareposte> ICs
[21:31:15] <SWPadnos> bummer
[21:31:20] <dareposte> 4-pin mostly
[21:31:42] <dareposte> i do have several opto22 SCRs
[21:31:46] <SWPadnos> oh, so you'll have to make boards with power, pull-ups/pull-downs, connectors, terminals, and the optos
[21:31:48] <dareposte> or SSRs i guess they call them
[21:31:55] <SWPadnos> SSR != SCR :)
[21:32:01] <dareposte> yeah my optos are self biasing though
[21:32:04] <dareposte> pretty simple
[21:32:10] <dareposte> just a current limiting resistor on the input and output
[21:32:10] <SWPadnos> only if there's a supply somewhere
[21:32:53] <SWPadnos> there are pull-ups available on the 5i2x pins, but I don't know the current source/sink capability
[21:33:12] <dareposte> 24ma
[21:33:17] <SWPadnos> you should test your optos before building up your boards
[21:33:18] <dareposte> according to their datasheet
[21:33:35] <dareposte> my optos only need 5ma on the input
[21:33:41] <dareposte> and they have a ctr of about 85%
[21:34:09] <dareposte> plenty to drive an SSR
[21:34:38] <SWPadnos> well, if they work then great. if not - not so great ;)
[21:34:50] <dareposte> they work fine with a parallel port output
[21:35:04] <dareposte> the mesa output seems a bit more robust than the parport ones
[21:35:26] <dareposte> it actually looks like you owuldn't need to optoisolate them at all, unless you need the level shifting too
[21:36:22] <dareposte> just don't cross any wires ;0(
[21:37:33] <SWPadnos> heh
[21:38:18] <dareposte> i've seen enough magic smoke
[21:38:43] <SWPadnos> I'm kind of bummed. I was watching a vouple of ebay lots of the AC output opto-22 modules, and I missed bidding on both
[21:38:55] <SWPadnos> they ended up going for about $1 each, which is a steal
[21:39:00] <dareposte> the snap-pacs?
[21:39:11] <SWPadnos> and of course there haven't been any more anywhere near that price since
[21:39:18] <SWPadnos> the ones that plug into their module racks
[21:40:09] <dareposte> those are pricey arent' they
[21:40:10] <dareposte> normally
[21:40:30] <SWPadnos> $10-$15 each usually
[21:40:40] <dareposte> oh
[21:40:51] <SWPadnos> the nice thing about that system is that you can mix and match inputs, outputs, and AC/DC on each bit
[21:41:11] <SWPadnos> so you're not stuck with 16 in and 8 out (at least not with the hostmot2 driver)
[21:41:23] <dareposte> yeah
[21:41:37] <dareposte> well i'm probably going to use some massive steppers on this one, so i may not even need a mesa 5i20
[21:42:15] <dareposte> steppers are just so much cheaper to buy and integrate than servos, i'm really not seeing the upside to servos at all for this
[21:42:22] <dareposte> maybe a spindle servo
[21:42:25] <SWPadnos> there are several Phoenix breakouts on eBay (these happen to be in my watch list): http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=260301183909 http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=140271044443 http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=270225273470
[21:43:11] <dareposte> cool
[21:43:42] <SWPadnos> servos have a few advantages: 1) real feedback, 2) "reserve power", 3) much higher speeds and dynamic range
[21:43:55] <dareposte> steppers go plenty fast though
[21:43:57] <SWPadnos> there are also disadvantages, namely that you need to use a feedback device like an encoder
[21:44:03] <SWPadnos> yep
[21:44:19] <dareposte> you don't have to gear them down so much to get good power out of them either
[21:44:38] <SWPadnos> Mariss of Geckodrive has this rule of thumb: if your power needs are <200W, use steppers. above 300W, use servos. between 200 and 300W, you get to figure it out :)
[21:44:48] <SWPadnos> yes you do actually
[21:45:09] <dareposte> the real feedback is nice, but you can put a 400ppr encoder on there and half step steppers to make sure you don't miss steps, then its not too bad
[21:45:16] <dareposte> stepper torque increases with lower speeds
[21:45:31] <SWPadnos> almost on both counts :)
[21:45:52] <SWPadnos> 1) if you're going to put a feedback device on a stepper, then you have eliminated the main disadvantage of a servo
[21:46:00] <dareposte> besides cost
[21:46:07] <dareposte> which to me is the main disadvantage
[21:46:12] <dareposte> i'm talking ac servos btw
[21:46:28] <SWPadnos> 2) the only thing you can do with a stepper and an encoder is fault, you can't use the feedback to make the machine work better
[21:46:29] <dareposte> haven't looked at the dc servos, although they seem to be popular
[21:46:37] <SWPadnos> oh, AC servos are still pretty expensive
[21:46:53] <dareposte> i was wanting to put 750-1000 watts on the x, and a little more on the z
[21:47:37] <SWPadnos> 3) technically stepper torque decreases as you increase speed - it never goes above the holding torque (so it doesn't increase once you get below the corner frequency)
[21:47:53] <SWPadnos> you pretty much need servos then, if you need 1HP +
[21:48:03] <SWPadnos> or are you talking oz-in?
[21:48:09] <dareposte> no i'm talking hp
[21:48:12] <dareposte> about 1 hp
[21:48:16] <dareposte> maybe 3/4 would be okay
[21:48:27] <dareposte> i'm shooting for a maximum thrust of about 3000 lbs
[21:48:39] <SWPadnos> how large a motor are you thinking of using? (NEMA frame size)
[21:49:27] <dareposte> hadn't picked yet
[21:49:29] <dareposte> probably 43
[21:49:36] <dareposte> maybe 34
[21:49:38] <SWPadnos> 42 then :)
[21:49:58] <SWPadnos> larger steppers can't go faster than about 600-1000 RPM, and that's with zero torque delivered to the load
[21:50:21] <dareposte> http://servo-motor.ws/manuals/L010533%20-%20Estun%20EMJ%2080mm.pdf
[21:50:36] <dareposte> yeah 42
[21:50:51] <SWPadnos> um. that's not a stepper ... :)
[21:51:16] <dareposte> that's what i was looking at for ac servos
[21:51:42] <SWPadnos> :)
[21:51:46] <SWPadnos> what kind of cost are those?
[21:52:34] <dareposte> $300
[21:52:41] <SWPadnos> not bad. and the drive?
[21:52:52] <dareposte> ebay special maybe
[21:53:01] <dareposte> otherwise $800-$1000 for a drive
[21:53:06] <dareposte> i think they would work with the rutex drives though
[21:53:16] <SWPadnos> gotta be careful there, AC servos often only work well with a matching drive
[21:53:34] <SWPadnos> they have different schemes for commutation and different optimal drive waveforms
[21:53:53] <dareposte> the anaheim drives are $500-$800 depending on the servo size
[21:54:11] <dareposte> for a 1hp drive about $500
[21:54:21] <SWPadnos> that's a pretty good deal
[21:54:32] <SWPadnos> then cables are another $150 probably :)
[21:54:47] <dareposte> probably
[21:55:14] <dareposte> it seems like 750w servo systems tend to be in that price range though
[21:55:20] <dareposte> $800-$1200 for a budget type unit
[21:55:38] <dareposte> i'm not sure how it would interface to EMC though
[21:56:04] <SWPadnos> analog or PWM for the command, encoder feedback for feedback
[21:56:35] <dareposte> yeah i'm not sure if their drives support that though, i woudl think so but i haven't verified
[21:56:39] <SWPadnos> you either split the encoder signals to EMC and the drive, or some drives will output quadrature back to a controller
[21:56:47] <dareposte> but i guess the point is you can get some monster steppers and drives for cheaper than that
[21:57:23] <SWPadnos> well, look very carefully at the torque curves before you plunk down any money
[21:57:53] <SWPadnos> large motors have a much much lower corner frequency, and once you pass the corner frequency the torque drops
[21:58:00] <dareposte> http://www.kelinginc.net/KL34H2160-62-8AT.pdf
[21:58:34] <SWPadnos> that's pulses per second, not RPM ...
[21:58:37] <dareposte> looks like they would be decent to about 600 rpm
[21:58:50] <SWPadnos> half-stepping, so 400 steps/rev
[21:59:02] <dareposte> ooh 300 rpm then
[21:59:05] <dareposte> missed the half stepping
[21:59:55] <dareposte> 60 in/min
[22:00:16] <SWPadnos> 2:1 gearing and 5TPI xcrew?
[22:00:19] <SWPadnos> screw
[22:00:30] <dareposte> yeah
[22:00:39] <dareposte> actually direct drive
[22:00:51] <SWPadnos> and 10TPI screw? :)
[22:01:13] <dareposte> 0.2" lead
[22:01:28] <dareposte> gives 0.001" per full step
[22:01:31] <SWPadnos> then something is screwy in your calculations (or mine) :)
[22:02:15] <dareposte> 300 rev/min * 0.2 in/rev = 60 in/min
[22:02:39] <dareposte> maybe dc servos would be worth looking into
[22:02:42] <SWPadnos> heh
[22:04:07] <dareposte> the problem is the biggest dc servos that seem to be readily available are only 226 in-oz
[22:04:33] <SWPadnos> at $200 each, I'd think you could find bigger ones
[22:04:40] <SWPadnos> (the cost of those steppers)
[22:05:11] <dareposte> those are nema 34 dc servos, peak torque is in teh 1200 in-oz range
[22:05:17] <dareposte> but i'm not sure about sizing them based on that
[22:05:21] <SWPadnos> nope
[22:05:30] <SWPadnos> you size based on the continuous torque
[22:05:53] <SWPadnos> but you get an extra boost during acceleration if it's needed, which steppers can't do
[22:06:29] <SWPadnos> you typically need a much higher torque rating for a stepper because of that (and the decreasing torque of a stepper vs. speed)
[22:06:40] <SWPadnos> bbiab - wife just got home
[22:07:03] <dareposte> so i figure with my 0.200" lead screw, desiring a 2500-3000lb thrust load, i'd like to have about 700 in-oz of torque if it's geared down 2:1
[22:07:39] <dareposte> i'm not sure if that's overkill or not though for a typical 16-18x40 lathe
[22:08:14] <dareposte> gotta go, i'm supposed to go set up some wireless router today
[22:14:23] <cradek> dareposte: I just used the 7i33 and 7i37 cards. I didn't need any separate breakouts.