#emc | Logs for 2005-07-23

[00:00:43] <roel01> i have to quit - can't hold it anymore pain like hell
[00:02:02] <robin_sz> ok
[00:02:13] <robin_sz> what did you do? fall off the bike?
[00:02:29] <roel01> jes
[00:02:34] <robin_sz> ouch
[00:02:37] <roel01> exreme hard off
[00:02:40] <robin_sz> remeber ...
[00:02:49] <robin_sz> paracetemol
[00:02:52] <robin_sz> codeine
[00:02:57] <robin_sz> ibuprofen
[00:03:06] <anonimasu> any will work in large enough doses
[00:03:17] <robin_sz> all three can be taken at the same time
[00:03:24] <anonimasu> heh
[00:03:47] <roel01> hehe i was in the hospital lots of xrays making
[00:03:55] <robin_sz> just keep em stacked 2 hours apart do you are never in pain
[00:04:02] <robin_sz> and wash them down with beer :)
[00:04:14] <anonimasu> robin_sz: final solution to pain.
[00:04:29] <robin_sz> roel01: collar bone?
[00:04:38] <robin_sz> or wrists?
[00:04:58] <roel01> but they said nothing is broken my ass it cant only bruces that hurts this way
[00:05:05] <roel01> collar aria
[00:05:29] <robin_sz> ouch
[00:05:35] <roel01> actualy half of the upper site is bruced
[00:07:23] <roel01> tinkeling and coolder arm cant be right
[00:07:58] <robin_sz> usual racers pains :)
[00:08:18] <roel01> i was fast thats right :)
[00:09:02] <roel01> second overall that day
[00:10:29] <roel01> cu in a short wile hey'
[00:10:32] <roel01> im off
[00:10:39] <anonimasu> later
[00:10:41] <roel01> sleep well
[00:15:05] <Jacky^> wow :)
[00:15:28] <Jacky^> anyone is looking Montreal 2005 on TV ?
[00:15:35] <Jacky^> nicee :P
[00:15:46] <robin_sz> CNC show?
[00:15:58] <Jacky^> hehe.. no
[00:16:16] <Jacky^> swimming show :D
[00:16:21] <anonimasu> * anonimasu aywns
[00:17:31] <Jacky^> Synchronized swimming, very nice..
[00:17:40] <robin_sz> ummm
[00:25:34] <fenn> * fenn is reading about celestial mechanics
[00:34:06] <robin_sz> thank $deity the universe isn't run by emc
[00:34:20] <robin_sz> <CLUNK>
[00:34:30] <robin_sz> oh sorry, the trajectory palnner is a bit rough
[00:46:28] <Jymmm> * Jymmm sighs
[00:46:31] <fenn> well the universe is only accurate down to the heisenberg uncertainty principle.. that's when you reach the resolution limit :)
[00:46:55] <Jymmm> fenn too much resolution for you! go away!
[00:47:23] <fenn> what's the data rate of C * hv ?
[00:47:32] <Jymmm> google it
[00:47:40] <fenn> it's a rhetorical question
[00:48:01] <robin_sz> 1/e
[00:48:14] <fenn> you mean 1/0
[00:48:19] <Jymmm> no 1\e
[00:48:54] <robin_sz> ach .. time for bed
[00:48:56] <fenn> it might be a finite number, but i'm too dumb to figure out where to start
[00:49:07] <Jymmm> Start here ---> .
[00:49:17] <Jacky^> Universe ?
[00:49:22] <robin_sz> so ...
[00:49:33] <robin_sz> the emc handbook pdf ...
[00:49:40] <robin_sz> why is it so broken ?
[00:49:46] <fenn> never got finished
[00:49:56] <robin_sz> gv and xpdf refuse to display it
[00:50:02] <robin_sz> multiple errors
[00:50:15] <fenn> dunno
[00:50:17] <fenn> works for me
[00:50:42] <fenn> i've been having lots of problems with .pdf files though
[00:50:45] <fenn> in general
[01:11:03] <fenn> john.. is it safe to use a small capacitor and schmitt trigger to introduce a delay in an electronic circuit.. like if i need a setup or hold time
[01:11:23] <fenn> is that the standard way to do it, or is there a better way?
[01:58:46] <Jacky^> night all
[02:29:05] <jmkasunich> sorry fenn, I was away
[02:29:35] <jmkasunich> RC time constant and schmidt can work, as long as the delay is significantly shorter than the high and low times of the signal
[02:30:32] <jmkasunich> example: you can delay a direction transition by a few or even tens of microsecond that way, but you can't delay a 10uS long step pulse for more than 1-2uS
[02:30:57] <fenn> ok good
[02:31:10] <fenn> i only need a couple hundred ns at most
[02:31:19] <jmkasunich> what logic family?
[02:31:25] <fenn> HCT
[02:31:37] <fenn> well.. i'm looking at a couple different chips
[02:31:43] <jmkasunich> should be OK then... outputs swing rail-to-rail
[02:32:15] <jmkasunich> the input threshold is ideally at 1/2 the rail, like HC... HCT has the thresholds offset, which means you'll have different delays on rising and falling edges
[02:32:54] <fenn> i want to use a binary up/down counter to keep track of position
[02:33:14] <jmkasunich> counting step and dir?
[02:33:22] <fenn> so i need to apply a setup time to the step signal
[02:33:29] <fenn> how do you say that?
[02:33:52] <jmkasunich> so you're sending dir to the up/down input, and step to the clock input?
[02:33:52] <fenn> i'm decoding quadrature output from an optical encoder, that's step/dir right?
[02:34:05] <fenn> yes
[02:34:13] <jmkasunich> oh, quadrature...
[02:34:20] <jmkasunich> no, that isn't step/dir
[02:34:22] <fenn> yes but decoded
[02:34:33] <fenn> run it through a logic circuit to get step/dir
[02:34:36] <jmkasunich> ok
[02:34:56] <fenn> they say "oh its such a simple circuit"
[02:35:10] <fenn> bugger that
[02:35:18] <jmkasunich> the logic ckt can be very simple if you only need one count per cycle, but if you want 4 counts per cycle it is non-trivial
[02:35:40] <fenn> oh.. actually i was going to divide the step signal anyway
[02:36:15] <jmkasunich> if you only need one count per cycle, do this:
[02:36:52] <jmkasunich> phase A becomes your clock, it clocks the counter, and a 74HCT74 D-latch
[02:36:58] <jmkasunich> B goes to the D input of the latch
[02:37:11] <jmkasunich> Q of the latch is your direction signal
[02:37:29] <jmkasunich> (if B is hi on the rising edge of A, that is up, if B is lo on the rising edge of A, that is down)
[02:38:01] <jmkasunich> in fact, you may be able to just send B to the counter up/down input, if that input is only sampled when the counter is clocked
[02:38:45] <fenn> that is confusing
[02:38:53] <fenn> maybe it will make sense if i draw a state diagram
[02:39:09] <fenn> and i need to look up how a d-latch works
[02:39:09] <jmkasunich> I can't talk without a pencil
[02:39:35] <jmkasunich> d latch sets its output to whatever state it's D input has on the rising edge of its clock input
[02:39:49] <jmkasunich> what chip are you looking at as a counter?
[02:39:50] <fenn> ok
[02:40:18] <fenn> ummm.. at this point pretty much any binary up/down counter
[02:40:31] <fenn> they only make them in 4-bit versions it seems
[02:40:34] <jmkasunich> how fast do you need to count?
[02:40:35] <fenn> but that will probably be ok
[02:40:58] <fenn> well... 500 cycles/rev encoder = 2000 pulse/rev
[02:41:02] <fenn> 2700 max rpm
[02:41:17] <fenn> so either roughly 20 khz or 90 khz
[02:41:26] <jmkasunich> and only a 4 bit counter, it will overflow pretty fast ;-)
[02:41:48] <fenn> i will be sampling with emc at like 40 khz right?
[02:41:55] <fenn> er, maybe not
[02:42:07] <jmkasunich> what exactly are you trying to do?
[02:42:15] <fenn> control 6 servos via parallel port :)
[02:42:24] <fenn> spending under $100 total
[02:42:30] <jmkasunich> tall order
[02:42:34] <fenn> not really
[02:42:41] <fenn> you can cut the data rate down to suit
[02:42:49] <jmkasunich> what are you using for DACs?
[02:42:59] <fenn> that's why i was going to divide the encoder output, to match the data rate
[02:43:20] <fenn> DACs... well, probably something simple like a transistor.. one-bit DAC :)
[02:43:28] <jmkasunich> PWM or something?
[02:43:35] <fenn> i dont know.. it depends how many bits i have free on the parallel port
[02:44:00] <jmkasunich> well unless you treat it like a bus, you simply aren't gonna have enough bits
[02:44:08] <fenn> i am going to treat it like a bus
[02:44:19] <fenn> which cuts my sampling rate by n, where n is the number of devices on the bus
[02:44:41] <fenn> so no 40 khz sampling rate
[02:44:45] <jmkasunich> do yoy already have servo amps and just need +/-10V, or are you trying to make amps too (under $100)?
[02:44:52] <fenn> making amps too
[02:45:02] <fenn> small motors
[02:45:07] <fenn> 11 watts i think
[02:45:25] <jmkasunich> you got your work cut out for you then
[02:45:33] <jmkasunich> power stage: H bridge
[02:45:37] <jmkasunich> power stage drivers
[02:45:52] <fenn> 22 watts actually
[02:45:54] <jmkasunich> PWM generator (both number of channels and speed rule out software PWM)
[02:46:06] <jmkasunich> DAC to feed PWM generator
[02:46:21] <jmkasunich> encoder counters
[02:46:36] <fenn> addressing comparators
[02:46:49] <jmkasunich> ?
[02:46:50] <fenn> a latch does both directions right?
[02:47:08] <jmkasunich> no (if I understand the question)
[02:47:14] <fenn> like, if the comparator senses that the address is for that device, and it sends enable to the latch,
[02:47:19] <jmkasunich> you talking about something like a 74HC374 latch?
[02:47:27] <fenn> i dont know yet
[02:47:49] <fenn> my pdf viewer is busted so it takes forever to look up datasheets
[02:47:56] <jmkasunich> hint: you don't want address comparators
[02:47:56] <fenn> driving me nuts
[02:48:13] <jmkasunich> lots of hardware to do something that can be done simpler
[02:48:38] <fenn> i'm thinking, something that looks at 4 bits, and says "is this equal to 0110"?
[02:48:51] <fenn> if so, it sends a signal to the latch
[02:49:18] <fenn> the latch gets the signal, and connects the data lines to the DAC inputs (or whatever is on the other side of the latch)
[02:49:28] <jmkasunich> you can use a 138 to decode 8 ports (3 lines)
[02:49:29] <Phydbleep> fenn: You want a BCD>Octal/Decimal decoder
[02:49:43] <jmkasunich> 74HCT138
[02:50:02] <jmkasunich> three address lines in, two active lo and one active hi enable in, 8 active low outputs
[02:50:18] <jmkasunich> when all enables are in their active state, one output (selected by the address lines) goes lo
[02:50:26] <jmkasunich> if any enable is inactive, all output are high
[02:50:52] <fenn> hold on.. gotta snort some coke to keep my brain running
[02:51:08] <jmkasunich> I hope you're only kidding
[02:51:10] <fenn> :P
[02:51:29] <fenn> never had any electronics education
[02:51:34] <jmkasunich> 74HC374: octal tristate D-latch:
[02:51:45] <jmkasunich> 8 data inputs, 8 outputs, one clock, one enable
[02:52:07] <fenn> ok after reading that three or four times i got it
[02:52:08] <jmkasunich> on the rising (IIRC) edge of clock, the 8 internal latches capture the state of the 8 inputs
[02:52:33] <jmkasunich> if the enable input is active (lo), the 8 outputs show the state of the 8 internal latches
[02:52:48] <jmkasunich> if enable is hi, the outputs are tri-stated (high impedance)
[02:53:26] <jmkasunich> so one 138 and 6 374's can give you 6 output ports, 8 bits each
[02:53:38] <fenn> tri-stated?
[02:54:02] <jmkasunich> yeah, basically open-circuit, they don't drive hi or low, they just sit there
[02:54:06] <fenn> ok
[02:54:13] <fenn> just floating voltage
[02:54:33] <jmkasunich> usefull for input ports, you can connect multiple chips to one bus, and enable only the one you are interested in
[02:54:49] <fenn> ah.. otherwise they would interfere with each other
[02:54:55] <jmkasunich> yep
[02:55:17] <jmkasunich> momentary change of subject: what do you know about "Wno-strict-aliasing"?
[02:56:33] <fenn> nothing at all
[02:56:51] <fenn> * fenn googles
[02:58:02] <jmkasunich> our mystery coder (Yabo Sukz) added it to the make files and now make is failing on three of the four compile farm slots
[02:58:16] <fenn> The documentation states that the option -fstrict-aliasing is not
[02:58:16] <fenn> > invoked for any optimization levels because it is new and relatively
[02:58:16] <fenn> > untested.
[02:58:46] <jmkasunich> sounds like a good reason to not use it
[02:58:55] <fenn> what is aliasing?
[02:59:06] <jmkasunich> I suspect the failures are because we often use older compilers for kernel related stuff
[02:59:21] <jmkasunich> aliasing relates to some forms of optimization
[03:00:02] <jmkasunich> suppose you have a pointer to some variable, call the pointer foo
[03:00:11] <fenn> just read the wikipedia article
[03:00:18] <jmkasunich> ah, better
[03:00:28] <jmkasunich> url handy?
[03:00:33] <fenn> http://en.wikipedia.org/wiki/Aliasing_(computing)
[03:00:55] <fenn> there are 2 kinds of aliasing
[03:01:52] <jmkasunich> yeah
[03:02:13] <jmkasunich> the strict-aliasing relates to the amount of optimization gcc can do
[03:02:44] <fenn> so you dont access memory out of bounds on accident?
[03:03:05] <fenn> * fenn wonders which version of "aliasing" its referring to
[03:03:29] <jmkasunich> if it is forced to assume that nay pointer accessed variable can be aliased, then it can't store temporary results internally and just write to ram after a series of calculations, because for all it knows, the intermediate result might be accessed in the middle of the calculatoin thru an alias
[03:03:35] <jmkasunich> computing version
[03:03:56] <jmkasunich> s/_nay_/any
[03:04:13] <jmkasunich> gawd I can't spell
[03:04:36] <fenn> kinda similar to atomicity then
[03:04:41] <jmkasunich> kinda
[03:05:08] <jmkasunich> any way, Yabo (I wish I know who that person is...) added it and it broke stuff
[03:05:19] <fenn> yeah he tends to add a lot of commits at once
[03:05:30] <fenn> there's like 20 files that have empty lines added
[03:05:38] <jmkasunich> with less than detailed descriptions
[03:05:54] <fenn> it was broken before he did anything actually
[03:05:58] <fenn> at least on my machine it was
[03:06:12] <fenn> well, i ahvent updated yet, i can tell you what the error was
[03:06:26] <jmkasunich> I had a clean compile last night, but now it's failing with:
[03:06:41] <jmkasunich> cc1: Invalid option `-Wno-strict-aliasing'
[03:06:59] <fenn> oh.. maybe that flag isnt supported in your old gcc
[03:07:13] <jmkasunich> that's my theory
[03:08:35] <fenn> this is the error i get from an update a couple nights ago: http://pastebin.com/318935
[03:08:50] <fenn> i have an older version also that compiles fine
[03:10:58] <fenn> emcmot_comm_timeout_count++; is the first error
[03:11:13] <fenn> (not defined)
[03:11:35] <jmkasunich> hmmm... you made the last changes in that file ;-)
[03:11:50] <fenn> maybe i did
[03:11:55] <fenn> i forget now
[03:12:09] <jmkasunich> commented out "spammy debug messages"
[03:12:12] <fenn> right
[03:12:21] <fenn> wtf
[03:12:35] <fenn> how does commenting out printf "blah blah" mess it up
[03:12:42] <jmkasunich> dunno...
[03:13:55] <fenn> i was messing around with adding include files to see if i could get EMC_DEBUG to work
[03:14:05] <fenn> but i think that's only available in kernel space
[03:14:34] <fenn> i might have deleted an include file on accident when i removed the ones i put in?
[03:14:54] <jmkasunich> doesn't look like it
[03:16:15] <jmkasunich> (well, you didn't commit it with deleted include files anyway)
[03:16:29] <jmkasunich> do a cvs diff, see if your local copy is messed up compared to cvs
[03:16:43] <fenn> i will probably get a lot of spam from yabo sukz
[03:16:52] <jmkasunich> why?
[03:22:05] <fenn> i can comment out #includes and the compiler will skip over them, right?
[03:22:13] <jmkasunich> yeah
[03:22:29] <jmkasunich> if you are trying to fix those spammy messages, wait a minute
[03:22:46] <jmkasunich> I put them in there, and I didn't use the normal DEBUG mechanism
[03:22:51] <fenn> well right now i'm trying to figure out what i broke
[03:22:59] <jmkasunich> so you can include until you are blue in the face, and they will never go away
[03:23:12] <jmkasunich> cvs diff, see if your stuff differs from CVS
[03:23:28] <fenn> i put in the code for the DEBUG mechanism in iocontrol.cc
[03:23:32] <jmkasunich> CVS can tell me exactly what you changed
[03:23:40] <fenn> but it was undefined in usrmotintf.cc
[03:25:57] <fenn> http://pastebin.com/318941
[03:27:23] <jmkasunich> line 22 is the problem
[03:27:53] <jmkasunich> you started the comment at line 20, ended it on 21, the } is outside the comment, and fscked up the nesting further down
[03:27:56] <jmkasunich> (I think)
[03:29:18] <fenn> whoops
[03:29:19] <fenn> good eyes
[03:29:21] <jmkasunich> the line numbers I was just quoting are the pastebin line nums, not the file lines
[03:29:27] <fenn> right
[03:29:34] <jmkasunich> BTDTGTTS
[03:29:53] <fenn> what's this part all about? printf("axis acc: ?\t");
[03:30:05] <fenn> pastebin line 28 and 30
[03:30:17] <jmkasunich> I tend to use #if 0 and #endif to comment stuff now, instead of actual comments - got bit once too often by nesting of /* */
[03:30:47] <jmkasunich> I think I was printing out some info on a per-axis basis
[03:30:59] <fenn> why'd it change on its own? i never touched that line
[03:31:12] <jmkasunich> dunno
[03:31:51] <jmkasunich> let me take a look at the cvs version
[03:33:30] <fenn> i wonder if cvs diff hiccuped on a funny hidden character
[03:33:32] <jmkasunich> dont know... that entire block is inside an #if 0 anyway
[03:34:02] <jmkasunich> testing
[03:34:20] <fenn> there's two spaces in earlier cvs versions, one space in HEAD
[03:34:41] <fenn> i'm only editing files with kate
[03:34:49] <jmkasunich> I deleted the space and the \t, put them back in, and did a diff, nothing came up
[03:35:08] <fenn> weird
[03:35:29] <jmkasunich> I have one suggestion...
[03:35:49] <jmkasunich> delete usrmotintf.cc, do cvs up
[03:35:55] <jmkasunich> IOW start over with a fresh one
[03:36:05] <fenn> yeah
[03:36:32] <fenn> i checkout a new one and apply the changes i made to that one, then cvs commit
[03:36:39] <fenn> just to make sure it works
[03:36:58] <jmkasunich> check out new, apply changes, _cpmile_, _test_, then commit ;-)
[03:37:04] <fenn> thats what i mean
[03:37:05] <jmkasunich> dammit
[03:37:07] <jmkasunich> compile
[03:37:33] <fenn> glad it was something simple in the end
[03:37:47] <jmkasunich> you know the one that talks about five messages can probably just be deleted
[03:38:17] <fenn> btw how do i know if something is in kernel space or user space?
[03:38:29] <fenn> since apparently the whole EMC_DEBUG mechanism is in kernel space
[03:38:48] <jmkasunich> anything .cc is user space
[03:39:00] <jmkasunich> beyond that it gets complicated
[03:39:30] <fenn> iotaskintf.cc has EMC_DEBUG in it
[03:39:40] <jmkasunich> you can look in the makefiles, there are variables SRCS and RTSRCS (I think, the makefiles got changed a lot because of kbuild)
[03:40:03] <jmkasunich> EMC_DEBUG isn't kernel space only
[03:40:21] <fenn> how come i get not defined errors when i try to use it?
[03:40:29] <fenn> it's defined in emcglb.h
[03:40:31] <jmkasunich> dunno
[03:40:41] <fenn> if i #include emcglb.h it says its not defined
[03:40:59] <fenn> even if
[03:41:02] <fenn> bleh
[03:41:19] <jmkasunich> the five printfs in usrmotWriteEmcmotCommand() should just be removed anyway
[03:41:26] <fenn> ok
[03:41:40] <fenn> seems useful to have a debug message system
[03:41:41] <jmkasunich> note that they aren't indented... that's what I do when I'm sticking in temporary printfs during debugging
[03:41:52] <jmkasunich> I had no intention of committing with them in there
[03:41:58] <fenn> yeah
[03:42:23] <fenn> i didnt want to just delete something i didnt know what it was there for
[03:42:39] <jmkasunich> well now you know... I'm the guilty one
[03:42:47] <fenn> jmk, you're fired.
[03:42:52] <fenn> :)
[03:42:53] <jmkasunich> I can delete them if you want...
[03:43:14] <fenn> ok
[03:44:17] <fenn> time flies when you're having fun, eh
[03:44:56] <CIA-8> 03jmkasunich * 10emc2/src/emc/motion/usrmotintf.cc: removed some debug printfs that I added months ago and forgot about
[03:45:03] <jmkasunich> there, my great accomplishment for today
[03:45:24] <fenn> i ate a whole canteloupe.. that's my accomplishment for today
[03:45:37] <jmkasunich> that's a lot of mellon
[03:45:42] <jmkasunich> melon anyway
[03:45:47] <fenn> its a muskmelon actually.. about twice the size of a canteloupe
[03:45:59] <fenn> one down, three to go
[03:46:02] <jmkasunich> geez
[03:46:19] <fenn> there's a watermelon too.. i dont know what i'm going to do
[03:47:06] <jmkasunich> on the subject of massive eating, I stumbled across this a couple days ago: http://katestelnick.com/
[03:48:30] <fenn> wow.. eleven pounds
[03:48:44] <jmkasunich> talk about bloat
[04:18:50] <CIA-8> 03jmkasunich * 10emc2/src/hal/classicladder/Makefile: removed -fstrict_aliasing and -Wno-strict-aliasing... the latter caused compile errors on 3 of 4 BDI systems in the compile farm, and the former may not be safe for kernel modules and related code
[04:19:27] <CIA-8> 03jmkasunich * 10emc2/src/rtapi/examples/shmem/Makefile: removed -fstrict_aliasing and -Wno-strict-aliasing... the latter caused compile errors on 3 of 4 BDI systems in the compile farm, and the former may not be safe for kernel modules and related code
[04:22:56] <CIA-8> 03jmkasunich * 10emc2/src/hal/components/blocks.c:
[04:22:56] <CIA-8> added AND, OR, GAIN, and LOWPASS components to HAL, as originally coded by Knud
[04:22:56] <CIA-8> Dombrowsky. I changed AND and OR to AND2 and OR2 to indicate that they are
[04:22:56] <CIA-8> two-input and allow for wider gates in the future. Also added a NOT function.
[04:39:18] <jmkasunich> goodnight all
[05:53:18] <Jymmm> Jymmm is now known as Red70sShow
[05:53:18] <Red70sShow> Red70sShow is now known as Jymmm
[08:07:56] <Jymmm> anyone around?
[08:15:43] <A-L-P-H-A> no
[08:15:49] <A-L-P-H-A> just us here ghosts
[08:16:12] <A-L-P-H-A> stupid friend was in the states too long, she's now saying "y'all"
[08:21:20] <Jymmm> That's not States, that's hick
[08:21:50] <Jymmm> But no worse than visiting Canada and saying 'eh', Eh!
[08:22:25] <Jymmm> any idea what thomson rails and bearings cost?
[08:36:15] <A-L-P-H-A> hey Jymmm.
[08:36:19] <A-L-P-H-A> got any plans for bb guns?
[08:36:27] <Jymmm> none
[08:36:37] <A-L-P-H-A> thomson rails, not that expensive... www.mcmaster.com
[08:36:41] <A-L-P-H-A> bearings expensive
[08:36:59] <A-L-P-H-A> if you're going for unsupported, just get precision ground shafting.
[08:37:02] <A-L-P-H-A> if supported, good luck
[08:37:22] <Jymmm> the breadloaf looking rails
[08:39:29] <A-L-P-H-A> oh, those kind... no clue.
[08:39:35] <A-L-P-H-A> I was talking about cylinders/bars.
[08:39:42] <Jymmm> ah
[08:51:23] <robin_sz> if using unsupported rails, you'll have a big advantage over your competitors
[08:51:44] <robin_sz> especially if you are milling curved surfaces
[08:52:42] <Jymmm> or have warped materials to begin with
[08:52:50] <robin_sz> * robin_sz nods
[08:53:23] <robin_sz> could be a bit of a problem doing flat surfaces though
[08:54:07] <Jymmm> Nah, you just use bowed endmills
[08:54:23] <robin_sz> I still think Igus rail (low precision) and Hiwin rail (high precision) offer the best value
[08:55:03] <Jymmm> hiwin == cheapest?
[08:55:11] <Jymmm> of linear rails
[08:55:17] <robin_sz> yeah
[08:55:38] <robin_sz> a 15mm linear rail, 750mm long is �40
[08:55:48] <robin_sz> 60 USD
[08:55:56] <robin_sz> carriages are �20
[08:56:25] <robin_sz> Igus rail is half that price
[08:57:06] <Jymmm> Ok, heres the deal.... I got the replacement parts they made for me and fucked up. They would like to offer to change out the rail and skate bearings for 20mm THK style linear rails (on X and Y only) for an additional $285 USD
[08:57:20] <Jymmm> and they fucked up
[08:57:44] <robin_sz> well, no they didn't really
[08:58:10] <Jymmm> No the replacement parts they sent me were fucked up.... too short by 1"
[08:58:41] <robin_sz> you gave them full engineering drawings of each part?
[08:58:53] <Jymmm> No, this is their design
[08:59:17] <Jymmm> The router I bought from K2CNC, remember?
[08:59:25] <robin_sz> I dont remember
[08:59:47] <robin_sz> but if they are offering to swap out unsupported rail for linear rail ... take it
[09:00:02] <Jymmm> the rail snow are supported
[09:00:03] <robin_sz> find out whose rail though ;)
[09:00:12] <Jymmm> I'm suspecting hiwin
[09:00:21] <Jymmm> as they are the cheapest
[09:01:04] <robin_sz> 20mm is plenty big enough for a router .. 15mm is fine, so they havent goen too cheap
[09:01:18] <Jymmm> http://www.k2cnc.com/Picture/KS-2525gallery/pages/Pic%20cnc%20router%2025x25%20(4).htm
[09:01:33] <Jymmm> that is what it has now.... uses ABEC7 skate bearings
[09:02:26] <Jymmm> http://www.k2cnc.com/Picture/KS-2525gallery/pages/Pic%20cnc%20router%2025x25%20(2).htm
[09:02:35] <A-L-P-H-A> heh.
[09:02:35] <Jymmm> lil better image of the existing rails
[09:02:40] <A-L-P-H-A> so they cut it 1" too short?
[09:02:53] <A-L-P-H-A> so what are you lacking? Are you sure you're missing 1" of travel?
[09:02:59] <robin_sz> fuck, that looks expensive
[09:03:05] <Jymmm> They made the replacement ballscrew too short
[09:03:17] <Jymmm> robin_sz what does?
[09:03:35] <robin_sz> that carriage with the skate bearings .. what a bunch of idiots
[09:03:40] <A-L-P-H-A> I really don't like their slide design.
[09:03:49] <A-L-P-H-A> with the skate bearings.
[09:04:06] <robin_sz> that must cost twice what proper linear rail costs
[09:04:08] <A-L-P-H-A> I'm inclinde to agreew ith robin_sz, about just getting premade slides.
[09:04:22] <Jymmm> the skate bearings actually isn't bad...
[09:04:26] <A-L-P-H-A> robin_sz, unless there's no precision in it.
[09:04:44] <robin_sz> useless for a router too
[09:05:02] <Jymmm> I only get .000.5 deflection for the whole travel
[09:05:06] <A-L-P-H-A> well. Jymmm. have fun. :) heh.
[09:06:04] <Jymmm> gee, thanks.
[09:07:56] <A-L-P-H-A> what are the new slides like? Are you sure they are short some 1"?
[09:08:04] <A-L-P-H-A> Are you getting the same about of travel?
[09:08:18] <A-L-P-H-A> about=amount
[09:08:20] <Jymmm> I said the ballscrew is too short
[09:08:33] <A-L-P-H-A> the ballscrew? for the coupling? or travel?
[09:09:56] <Jacky^> morning
[09:10:21] <A-L-P-H-A> hi
[09:10:29] <Jacky^> hey A-L-P-H-A
[09:11:17] <A-L-P-H-A> fine. bye jymmm.
[09:11:30] <A-L-P-H-A> robin_sz... still playing with the gecko g2002?
[09:11:48] <Poincare> Hello all
[09:12:47] <Jacky^> A-L-P-H-A: hehe
[09:12:54] <Jacky^> hi Poincare
[09:14:15] <A-L-P-H-A> hi
[09:15:49] <Poincare> I found this company that's modifying Proxxon shapers and puts stepper motors on it. I was wondering if anyone already used it with emc
[09:16:41] <A-L-P-H-A> oh. sick. http://geckodrive.com/ycom/documents/C163R22_spiral.wmv
[09:16:48] <A-L-P-H-A> I want a g2002 now.
[09:23:32] <A-L-P-H-A> Poincare, don't know. you'll probalby have to ask on the email list.
[09:24:05] <Poincare> What do use emc for?
[09:24:10] <Poincare> What do _you_ use emc for?
[09:24:11] <A-L-P-H-A> milling.
[09:24:31] <A-L-P-H-A> I use it for milling. on my retrofitted mill.
[09:24:40] <A-L-P-H-A> and it's 4:38am... time to sleep
[09:24:44] <Poincare> ah ok
[09:24:55] <Poincare> it's 10:38 here :-)
[09:25:01] <Poincare> have a nice sleep
[09:25:09] <toka> milling wood, just starting, its 10:38 here too ;-)
[09:25:46] <Poincare> as a hobby or for professional use?
[09:26:30] <toka> booth, trying to do some investigations into high tech self-providing
[09:28:07] <Poincare> Well, I'm looking for something to drill holes and cutouts in aluminium
[09:28:20] <Poincare> for the electronic equipment I make
[09:28:30] <Poincare> for small series etc...
[09:29:24] <toka> something or someone ?
[09:30:24] <Poincare> something :-)
[09:30:59] <toka> are you planning to buy a milling machine or to build one yourself ?
[09:31:06] <Poincare> I do get this ideas at weird times and want to make/try it at weird times :-)
[09:31:49] <Poincare> I saw someone on a tradeshow in Friedrichshaven last month who modifies Proxxon milling machines
[09:32:16] <Poincare> Price looks fine for me, but it comes with DOS software, brrrr
[09:33:03] <toka> I've got a old ISEL-mill without electronics. Actually I try to get it working.
[09:33:24] <Poincare> It's completely dead?
[09:33:49] <toka> It is running already. Now I start to get fammiliiar with emc
[09:34:20] <Jacky^> toka: familiar on a pda ?
[09:34:50] <toka> dont understand: what do you mean with pda (personal digital assistant ) ?
[09:34:57] <Jacky^> yeah
[09:35:09] <toka> not realy, why ?
[09:35:36] <Jacky^> I was thinking you was talking of Linux Familiar
[09:36:23] <Jacky^> :)
[09:36:45] <toka> just googled, seemst to be interesting ... what is the connection to emc ?
[09:36:56] <Jacky^> nothing..
[09:37:16] <Jacky^> should be fun run emc on Linux Familiar
[09:37:31] <Jacky^> but not possible I suppose
[09:38:14] <toka> you get a full powered pc for the price of a pda, what would be the benefit ?
[09:38:29] <Jacky^> Just fun..
[09:38:52] <Jacky^> I've an Ipaq 3970 with Gpe Familiar installed
[09:39:08] <Jacky^> so, I was asking ..
[09:40:05] <toka> sorry, leaving for breakfast, if someone is interested in sharing experience about emc and self build milling machines: http://coforum.de/?ThomasKalka
[09:40:48] <Jacky^> nice :)
[09:41:17] <Jacky^> toka: do you have a cnc machine ?
[09:42:25] <Jacky^> homebuilt ?
[09:43:01] <Poincare> off to work... see you later
[09:43:20] <Jacky^> later Poincare
[09:43:54] <Jacky^> I build from myself a prototype some mounth ago
[09:44:17] <Jacky^> I'm looking for a good 3D laser scanner project now
[09:44:36] <Jacky^> laser + webcam
[09:44:52] <Jacky^> to retrive 3D models
[10:04:22] <toka> http://www.muellerr.ch/engineering/laserscanner/tutorial/the_tutorial.html
[10:11:19] <Jacky^> yeah, already seen ;)
[11:45:51] <Jacky^> anyone know hot to run a program (gcode-file) from an arbitrary line ?
[11:51:48] <alex_joni> greetings
[11:51:52] <alex_joni> anyone around?
[15:12:05] <anonimasu> morning
[16:12:30] <CIA-8> 03yabosukz * 10emc2/src/ (Makefile.inc.in configure configure.in emc/log/Makefile): need flag to fix bug wit c-3+
[17:10:12] <Jymmm> Yo!
[17:18:09] <Jymmm> peem!
[17:26:56] <anonimasu> hey
[17:28:36] <Jymmm> oats
[17:56:53] <anonimasu> what's up?
[18:11:05] <Jymmm> bullshit
[18:12:17] <Jymmm> They sent me the replacemnt parts, they were screwed up. Now they are offering to convert from the skate bearing to THK rails for $285
[18:12:53] <Jymmm> So, now I'm trying to find street pricing on 20mm THK style rails
[18:13:22] <Jymmm> I think Hiwin, but not sure.
[18:15:12] <anonimasu> ok
[18:15:19] <_dreamer> hi
[18:17:40] <Jymmm> anonimasu : Well, with leadscrew made too short, why are they offering rails ?!
[18:18:02] <anonimasu> heh
[18:18:08] <anonimasu> no clue.
[18:20:15] <Jymmm> what you mean 'no clue'
[18:22:51] <anonimasu> I have no clue why they would do something like that.
[18:23:16] <Jymmm> Me neither, but I'm just wondering if $285 is worht it.
[18:24:34] <anonimasu> well, you still need new leadscrews..
[18:24:42] <anonimasu> it might be to compensate for the trouble..
[18:25:01] <anonimasu> it's a good deal on rails for sure..
[18:25:08] <anonimasu> if they are good
[18:25:19] <anonimasu> but well rails > skate bearings..
[18:48:37] <robin_sz> meep?
[18:49:29] <anonimasu> m33p
[18:49:59] <robin_sz> interesting to read about Jymms router woes
[18:50:17] <robin_sz> seems those guys selling the routers aitn very clueful huh?
[18:51:14] <robin_sz> I saw some bad points in the design too
[18:52:33] <anonimasu> bleh I need a cnc lathe :/
[18:52:57] <anonimasu> I need to turn a screw with 2 different threads on it..
[18:53:01] <robin_sz> that gantry driven off a single screw in the middle, its going to be bad for loads applied at one side
[18:53:11] <anonimasu> going in Thread1<>thread2
[18:53:14] <anonimasu> for a gripper..
[18:53:17] <anonimasu> for my toolchanger
[18:53:27] <robin_sz> gripper?
[18:53:35] <anonimasu> yeah the changer fork..
[18:53:37] <robin_sz> mmmm . pneumatics?
[18:54:09] <anonimasu> maybe..
[18:54:19] <anonimasu> I might machine the fork solid..
[18:54:37] <anonimasu> maybe a block with 2 precision holes & pisons..
[18:54:57] <anonimasu> need to grip the tool, other then the fork..
[18:55:57] <anonimasu> http://images.google.se/imgres?imgurl=http://www.whitneysystems.com/Data/Images/Image104-tn1.jpg&imgrefurl=http://www.whitneysystems.com/Custom%2520CNC%2520Tool%2520Changers.htm&h=200&w=290&sz=8&tbnid=I68tWOfxmaQJ:&tbnh=75&tbnw=110&hl=sv&start=6&prev=/images%3Fq%3Dcnc%2Btool%2Bchangers%26svnum%3D10%26hl%3Dsv%26lr%3D
[18:56:45] <anonimasu> similiar design
[18:56:56] <anonimasu> * anonimasu wishes he could fit retainer knobs easily
[18:59:19] <robin_sz> one word ...
[18:59:27] <robin_sz> do not even consider makign your own
[18:59:35] <anonimasu> toolchanger?
[18:59:40] <anonimasu> or drawbar..
[18:59:42] <robin_sz> retianer balls
[18:59:51] <anonimasu> balls?
[18:59:58] <robin_sz> retainer knobs
[19:00:01] <anonimasu> bleh.. they are like $25
[19:00:06] <robin_sz> cheap ...
[19:00:12] <robin_sz> bargain!
[19:00:13] <anonimasu> no way!
[19:00:19] <robin_sz> well, your funeral
[19:00:26] <anonimasu> I was just kidding ;)
[19:00:31] <robin_sz> phew
[19:00:33] <anonimasu> the trouble is the drawbar, really
[19:00:36] <anonimasu> and the taper..
[19:00:38] <robin_sz> yeah
[19:00:51] <anonimasu> I'll use the drawbar I have now to push the tool out..
[19:01:08] <anonimasu> but I am working on the fork to hold the tool and to grip it..
[19:03:22] <anonimasu> :)
[19:05:31] <anonimasu> http://www.laserspec.net/cnc-equipment/lsi800.html
[19:05:33] <anonimasu> ^_^
[19:05:39] <anonimasu> cute
[19:30:43] <Jacky^> hi
[19:30:56] <Jacky^> who is kidding ? :P
[19:32:24] <Jacky^> anyone know a good CD collection of 3d Clipart ?
[19:37:33] <robin_sz> anonimasu: neat looking router .. wonder how much
[19:51:45] <Jymmm> $2000 USD sound snice =)
[20:54:50] <LawrenceG> hi John
[20:55:33] <jmkasunich> hi
[20:56:32] <LawrenceG> I am looking for ideas for servo amps to use with the mesa 5i20 card... I need something that accepts pwm and a dir bit... any ideas?
[20:56:54] <jmkasunich> nope
[20:56:58] <LawrenceG> I would like to build something if I cant find an ebay special
[20:57:30] <LawrenceG> who on the list plays with that stuff... Jon does... anyone else come to mind?
[20:57:58] <jmkasunich> nobody in particular... I'd just post the question to the list
[20:58:23] <LawrenceG> will try tomorrow when the list is active....
[20:59:43] <LawrenceG> The guys in Germany seem to be using the mesa cards... I will try and find out what they are using
[21:00:53] <LawrenceG> Imperator and swpadnos were waiting for cards ... havent heard a peep from them
[21:04:53] <fenn> peep?
[21:05:38] <LawrenceG> meep meep
[21:06:11] <LawrenceG> "any sound"
[21:11:36] <fenn> hey stranger
[21:11:46] <les> hi fenn
[21:11:53] <fenn> set your hair on fire from across the room yet?
[21:11:57] <jmkasunich> howdy less
[21:12:00] <jmkasunich> les
[21:12:03] <jmkasunich> ;-)
[21:12:05] <les> what hair?
[21:12:11] <les> hi john
[21:12:44] <les> been away a while....got a tractor and am prepping property etc
[21:13:22] <les> dig pond, take out trees, and stuff
[21:13:37] <les> oh and my two hole par 4 golf course...
[21:13:41] <les> heh
[21:26:17] <LawrenceG> evenin' les
[21:26:28] <les> hi lawrence
[21:26:57] <les> been away...playing with new summer toy
[21:27:04] <les> let's see...
[21:27:07] <les> http://www.tractorbynet.com/forumfiles/692005-tractorlr.jpg
[21:27:16] <LawrenceG> nice day in the north west... just getting ready to go out to a ham radio club bbq
[21:27:24] <les> cool
[21:28:06] <LawrenceG> oh yea... nice toy... had a kabota 4wd about that same size.... very handy machine around the farm
[21:28:26] <les> My dad is a ham but I was always an audio type...a little lower frequency
[21:28:33] <les> yes very handy
[21:28:52] <LawrenceG> not bad in the shop for a portable crane either
[21:29:24] <les> well I am getting forks for it....it can pick up 1500 lb to 7 feet
[21:29:37] <les> not quite a forklift...
[21:29:37] <LawrenceG> the pto is great for running pumps, welders light plants etc
[21:29:42] <les> but handy.
[21:29:58] <LawrenceG> easier than straining the back!
[21:30:01] <les> yeah this is 30 hp on the pto
[21:30:10] <les> 540 or 1000 rpm
[21:30:44] <LawrenceG> lots of beef... mine had 20hp on the pto and 27 overall engine hp... nice 3cylinder diesel
[21:31:01] <les> this is too
[21:31:40] <les> It will help me a lot
[21:31:54] <les> not cheap but it will outlast me i'll bet
[21:31:59] <LawrenceG> its amazing how much work they can do on 5 gal of diesel.... a full day..... do you have a backhoe attachment?
[21:32:39] <les> no....just a loader and bushhog....disc plows coming this week
[21:32:44] <les> and log splitter
[21:33:21] <A-L-P-H-A> stupid log splitter conversation in the 7x10minilathe group. wow is that group bloated with pompus windbags.
[21:33:36] <les> oh yeah?
[21:33:38] <LawrenceG> I used my hoe a lot... put in building footings and waterlines etc.... a few outhouse pits as well!
[21:34:08] <les> the one I am getting uses the tractor hydraulics...no engine needed
[21:34:39] <LawrenceG> a tractor driven splitter will be awesum.... fast and nothing will stop it.
[21:35:16] <les> Lots of things you can put on those....heh had to draw the line somewhere though...it cost more than a lot of new cars!
[21:35:36] <LawrenceG> 2 cars in some cases!
[21:35:41] <les> yeah.
[21:36:54] <anonimasu> yo
[21:37:18] <les> Hi anon
[21:37:25] <les> have been away a bit
[21:37:40] <LawrenceG> I also used a landscape rack a lot.... kind of a curved spring rake that when on the 3pt hitch... cleaned up 22 acres after the excavator pulled the stumps.
[21:37:55] <LawrenceG> s/rack/rake
[21:38:05] <anonimasu> les: yeah we've missed you a bit..
[21:38:10] <anonimasu> les: how are things going?
[21:38:15] <les> I hear those are good to have
[21:38:46] <les> ok anon. Have been doing outside stuff and also an acoustics research project
[21:38:59] <anonimasu> yeah, the one with the power generation..
[21:39:08] <les> yeah
[21:39:13] <anonimasu> how does it go?
[21:39:21] <les> lots of impedance matching with stubs
[21:39:50] <les> kinda tough...with stub matching I need a q of several thousand
[21:40:16] <les> Am trying low impedance piezopolymer now
[21:40:32] <anonimasu> ok
[21:40:50] <les> neat stuff.
[21:46:17] <Jymmm> hey les!
[21:50:24] <les> hey jymmm!
[22:05:39] <dmess> High all... : )====~~~~
[22:05:48] <jmkasunich> drooling?
[22:06:02] <dmess> nope
[22:06:14] <dmess> hoolin'
[22:20:28] <Jymmm> Anyone know the cost of 20mm THK style rails and slides?
[22:21:18] <Imperator_> Hi all
[22:21:25] <Imperator_> LawrenceG: have my card now
[22:22:11] <Imperator_> If you would like to have a amp, try the ones with +-10V Input
[22:24:47] <Imperator_> Jymmm: don't know the price of THK but BoschRexroth ones (Star) are about 80 EUR per slide and the Rails are 80 EUR per Meter in normal quality
[22:31:51] <Jymmm> are those the cheapies? I thought hiwin were the cheapest
[22:32:13] <fenn> jymmm just get some drawer slides already :)
[22:32:36] <Jymmm> fenn only to beat you over the head with!
[22:35:52] <fenn> anyone here from finland?
[22:36:38] <fenn> i know picnet is.. but he never says anything
[22:36:46] <Imperator_> The Bosch ones are not the cheapest, they are like THK I think
[22:37:06] <Imperator_> Hiwin are the cheapest I know
[22:37:43] <Imperator_> got some Bosch rails and slides from ebay :-) new ones of cause
[22:39:35] <Imperator_> Finnland !! There are the moskitos alive at the moment, right ???
[22:39:48] <fenn> yes
[22:39:56] <fenn> i'm from indiana, usa, not finland
[22:41:49] <Imperator_> and why are you searching for somebody from Finnland ?
[22:42:00] <Jymmm> fenn : Indiana, Well that explains EVERYTHING!
[22:42:22] <Jymmm> Imperator_ what was the damage on the rails you got?
[22:42:30] <Jymmm> fenn =)
[22:42:39] <fenn> i want to ask them if all finns are nutcase mountain-men at heart
[22:43:35] <Imperator_> damage ?? they are ok. Sometimes you get usefull stuff on ebay
[22:44:14] <jmkasunich> Imperator: I think he is asking the price (USA slang, refers to damage to your wallet)
[22:44:38] <Imperator_> jmk: ah ok
[22:44:40] <_dreamer> fins are all nutcase mountain-men at heart
[22:44:49] <Imperator_> thx
[22:44:57] <_dreamer> I am one, and I want to dig a hold 10000 ft deep with a cavern at the end to live in it
[22:45:19] <fenn> that's pretty deep
[22:46:18] <_dreamer> with cnc, I'll get there! lol
[22:46:22] <Imperator_> Jymmm: about 250 $ for two rails (700mm long) with four slides
[22:49:47] <Yuga> hi all
[22:50:02] <Imperator_> Hi
[22:50:17] <fenn> you get your racks'n pinions yet?
[22:50:40] <Yuga> nopes
[22:50:49] <Yuga> still cant find the ones i want
[22:51:02] <Imperator_> Yuga: you are from south africa ??
[22:51:09] <Yuga> yep
[22:51:23] <Imperator_> cool, which city
[22:51:49] <Yuga> east london
[22:52:53] <Yuga> u?
[22:53:58] <Imperator_> I'm from germany
[22:54:27] <Imperator_> was in capetown and bloomfontain last year
[22:54:49] <Imperator_> Bloemfontein
[22:55:15] <Imperator_> and in Durban
[22:55:26] <Yuga> aahh
[22:55:39] <Yuga> durbs = shithole... far to hot there
[22:56:03] <Imperator_> in summer ?
[22:56:16] <Yuga> even in winter
[22:56:18] <Imperator_> it was ok
[22:56:23] <Yuga> but yet... the summers are killer
[22:56:27] <Yuga> far to humid
[22:56:33] <Imperator_> jep
[22:56:45] <Yuga> what where u there 4?
[22:56:58] <Imperator_> buissenes trip
[22:57:10] <Yuga> what business?
[22:57:26] <Imperator_> was at rapdasa conference in bleom
[22:57:42] <Yuga> dont have a clue y some one would wanna come to sa if it wasnt for buisseness
[22:57:47] <Imperator_> that was about rapid- prototyping
[22:58:29] <Imperator_> know some people how like to spend there holidays in sa
[22:58:45] <Yuga> not my idea of fun
[22:58:50] <Imperator_> would like also to go there again
[22:59:00] <Yuga> Imperator_... sooo what u goto do with emc?
[22:59:08] <Yuga> got a cnc machine?
[22:59:20] <Imperator_> planning one
[22:59:24] <Yuga> aaahhh
[22:59:28] <Yuga> what type?
[22:59:31] <Imperator_> and collecting stuff on ebay
[22:59:34] <Yuga> router mill lathe?
[22:59:47] <Imperator_> high speed mill
[22:59:58] <Yuga> nice... servo's i am guessing?
[23:00:05] <Imperator_> polymer concrete frame
[23:00:22] <Imperator_> jep, Simens Simodrive Servos
[23:00:27] <Imperator_> Siemens
[23:00:31] <Yuga> got a addy for them?
[23:00:40] <Yuga> like to c what ppl are up to
[23:01:20] <Yuga> i am also in the process of planning a cnc machine
[23:02:05] <Imperator_> sa people realy like to shorten everything
[23:02:34] <Yuga> no point in typin it all
[23:02:44] <Imperator_> :-)
[23:02:52] <Yuga> got a addy for them?
[23:02:54] <Imperator_> what meany the C and the ppl ?
[23:03:06] <jmkasunich> see and people...
[23:03:10] <Yuga> yep
[23:03:12] <Imperator_> you mean where to get the servos ?
[23:03:25] <Yuga> yep.. where to get them...
[23:03:39] <Imperator_> puh, somewhere on ebay
[23:03:47] <Yuga> aahhh
[23:03:53] <Imperator_> John is the english english translator today
[23:04:00] <Yuga> * Yuga is going to be using stepper motors
[23:11:48] <Imperator_> the problem with ebay is that this stuff is now very expensive, because the people who are repairing the older CNC machines are buying them all the time
[23:12:51] <Imperator_> a smal Siemes Servo is about 1000 EUR, on ebay you get a new one for about 200 EUR, but that is even to much for hobby users
[23:13:07] <Imperator_> got mine for about 50-100 EUR
[23:13:16] <Yuga> shit... not bad
[23:13:38] <Yuga> the steppers i am wanting are like 200 each
[23:13:54] <Imperator_> 200 what ?
[23:14:07] <Yuga> $
[23:14:21] <Imperator_> very expensive for steppers
[23:14:28] <Yuga> they are realy big :)
[23:14:36] <Imperator_> how big
[23:15:11] <Yuga> http://www.campbelldesigns.com/stepper-motors.php
[23:15:14] <Yuga> the bottom ones
[23:15:20] <Jacky^> hi
[23:15:43] <Yuga> 1200 oz/in
[23:17:40] <Yuga> hi Jacky^
[23:18:43] <Imperator_> depends on what you want to do, but normaly a servo is better in that aerea
[23:19:11] <Yuga> yep... but they are far more expencive... doubt i could afford it
[23:19:36] <Imperator_> you will get nice resonance effects
[23:20:12] <Yuga> ?
[23:20:48] <Imperator_> a stepper don't turn, it makes stepps
[23:20:49] <Yuga> what u mean
[23:21:09] <Yuga> ya... and?
[23:21:23] <Yuga> expecting it to vibrate the machine more than the router?
[23:21:31] <Yuga> * Yuga is making a cnc router
[23:22:10] <Imperator_> you need a coupeling element that is not to stiff
[23:23:02] <Yuga> going to be using a rack and pinion aproach.... the pinion's going to be linked to the stepper via a timing belt
[23:23:28] <Yuga> that should unstiffen it enough :)
[23:23:58] <Imperator_> jep
[23:24:12] <Imperator_> what do you want to do with that machine
[23:24:17] <Yuga> just hope that it doesnt get too unacurate
[23:24:17] <fenn> you could use a timing pulley with a damping layer.. they make them for auto engines
[23:24:46] <Yuga> fenn... cool. something i did know :)
[23:25:03] <Imperator_> I think a normal timing belt is damping enough
[23:25:22] <Imperator_> that is why nobody is using that for machine tools
[23:25:47] <Yuga> ya... alittle worried about all the play i will get with the timing belt's and rack and pinnion
[23:25:56] <Imperator_> or better it is not damping it is elastic
[23:26:31] <Imperator_> belts are good for pick and place machines but not for machine tools
[23:26:44] <fenn> you can adjust for backlash in software.. i dont know if there are issues with that strategy or not
[23:30:09] <Yuga> the biggest problem i have with using a screw is getting one long enough... and shiped to sa
[23:30:42] <Imperator_> what size are you thinking about
[23:30:48] <Yuga> 3m
[23:31:05] <Yuga> that's what size i need... it's not even debatable
[23:31:13] <Imperator_> --> 40mm or 50mm spindel
[23:31:30] <Yuga> 40
[23:31:30] <Imperator_> for doing what ?
[23:31:49] <Yuga> that's how big the sheet's of wood are
[23:32:02] <fenn> what about chain drive? like a garage door opener
[23:32:15] <Yuga> think that is probibly less acurate?
[23:32:44] <fenn> it is less accurate than a ballscrew, for sure
[23:32:58] <fenn> when you're sticking several racks together, it might be about as accurate
[23:32:59] <Imperator_> you want to mill in wood or to engrave ?
[23:33:00] <Yuga> even less acurate than the rack
[23:33:29] <Yuga> mill mainly... would like to engrave... but not sure if it will be good enough
[23:33:57] <Imperator_> take spindels
[23:34:27] <Imperator_> ask Hiwin, they are about 1500$ I think
[23:34:50] <Imperator_> take one on each side
[23:35:35] <Yuga> spindel?
[23:35:42] <Imperator_> jep
[23:36:07] <Imperator_> we are building a machine with 1.7m in Y direction
[23:36:14] <Yuga> what about spindles?
[23:37:03] <Imperator_> we want to buy a 2m spindel with 32mm or 40mm diameter. It is about 800 EUR ->1000$
[23:37:39] <fenn> you mean ballscrew?
[23:37:45] <Imperator_> jep
[23:37:57] <fenn> spindle means the part that holds the cutting bit
[23:38:01] <Imperator_> sorry
[23:38:10] <Yuga> aaahhh... was alittle confused
[23:38:23] <Imperator_> in Germany we say Spindel
[23:38:39] <Imperator_> in german I mean
[23:39:03] <Imperator_> wrong translation
[23:40:58] <Yuga> ooohhhh... found some nice cheap ballscrews :)
[23:42:04] <Yuga> 523.2$ for a 3 meter one 1 1/2" dia
[23:42:38] <fenn> you better make a webpage, once you get it to work, for all your whining :)
[23:42:47] <Jacky^> ouch
[23:42:49] <Yuga> me fenn?
[23:42:53] <fenn> yeah
[23:42:59] <fenn> i wanna see pictures of this
[23:43:09] <Yuga> hey... i refuse to start untill i know what i want
[23:43:20] <Yuga> and i still dont have a clue.. so get use to the whining :)
[23:44:12] <fenn> i like this chain idea.. i may end up using it myself
[23:44:29] <fenn> seems much more efficient than screw drive
[23:44:42] <fenn> regular screws that is
[23:45:20] <Yuga> what kinda chain??? cause chains i have worked with have a shitload of play
[23:45:33] <fenn> well, if you apply preload to them it takes up all the play
[23:45:50] <fenn> then any error is in the difference in distance between roller pins
[23:46:08] <fenn> i'm talking about 3m sized machines
[23:46:16] <fenn> not expecting <.001" accuracy
[23:47:08] <fenn> i'm thinking either motorcycle chain or bicycle chain
[23:47:29] <fenn> more likely bicycle chain.. i wont be applying more than a hundred kg of force
[23:48:17] <Imperator_> the chain on my mountain bike is after 1000km about 3 elements longer !!! Don't think that is something for a machine tool
[23:48:42] <fenn> your mountain bike is submerged in an abrasive slurry
[23:48:43] <Imperator_> I throw away two of them each year
[23:48:52] <Imperator_> jep
[23:49:44] <fenn> well, nothing's perfect
[23:50:26] <Yuga> wonder if a 25mm ballscrew is thick enough
[23:50:51] <fenn> look up how to calculate the critical frequency of a ballscrew, and find out if that is below your maximum rpm
[23:50:53] <Yuga> any input for the whiner?
[23:51:47] <fenn> this is for acme screws, but it should apply to ballscrews: http://www.nookindustries.com/acme/AcmeGlossary.cfm
[23:51:58] <fenn> the main parameters are the stiffness of the material and geometry of the part
[23:52:25] <Yuga> ta
[23:52:32] <fenn> eh, it's about 3/4 of the way down
[23:52:51] <Imperator_> big machines are expensive !!! If you try to build them with cheap or to small stuf, you wil have something that dont run.
[23:53:03] <fenn> hah!
[23:53:14] <fenn> i'll show you! *shakes his fist*
[23:53:28] <Yuga> Imperator_... fenn is a cheap chap
[23:53:45] <fenn> but you have to do it with ingenuity, not by using wimpy versions of what the big guys use
[23:55:19] <Imperator_> jep
[23:56:29] <Imperator_> but a chain isn't the solutian
[23:57:07] <Imperator_> we are buying two screws, one for each side
[23:57:41] <Imperator_> one linear scale one each side also
[23:57:51] <Imperator_> servos
[23:57:58] <Yuga> those acme screw's are quite cool
[23:57:58] <Imperator_> and a granit table
[23:59:21] <fenn> Imperator_: you are milling metal, right?
[23:59:44] <fenn> i think yuga mostly will be doing plywood and mdf