#emc | Logs for 2005-09-23

[00:01:52] <zwelch> well, 1) wouldn't it be neat if the rtapi code could actaully be severed off from emc and provided as a "platform neutral" rtapi solution? 2) do you really want the rtapi directory to depend on libnml? 3) wouldn't it be better to tear the timer, shmem, and mutex stuff out of libnml and into a convenience library that is then used by libnml and rtapi?
[00:02:32] <zwelch> i don't want to duplicate code, but i'd rather do that than create a needless dependency
[00:03:44] <zwelch> there already seems to be a lot of duplicated code for these functions as it is, just looking at the rtapi directory. now you're telling me that libnml has its own little api too.
[00:05:15] <paul_c> 1) rtapi is already independant of emc2, it is a long way from providing a neutral RT solution. 2) I am more concerned with re-using code rather than duplicating it time and time again. 3) libnml is already a library.
[00:05:41] <paul_c> libnml predates rtapi.
[00:06:50] <paul_c> Oh, and there are already "standard" methods/calls for implementing much of what rtapi does.
[00:07:21] <zwelch> so why isn't emc using such?
[00:07:30] <paul_c> but JMK wanted to provide policy and method for anyone wanting to use it.
[00:09:13] <zwelch> regarding 3) and 3a), are you saying you don't want to touch libnml?
[00:09:55] <paul_c> I'm currently doing some work on libnml.
[00:10:09] <zwelch> okay, so you don't want *me* to touch it, that for sure ;)
[00:10:58] <zwelch> is there any reason that libnml can not be rewritten (someday) to use rtapi?
[00:11:30] <anna_emc> night all
[00:11:34] <paul_c> There is a hell of a good reason that libnml will NOT use rtapi
[00:11:42] <zwelch> because a) libnml looks to be in C++, right? b) rtapi is in C, c) rtapi's scope is much more focused on threading/IPC/etc
[00:11:42] <paul_c> night anna_emc
[00:12:23] <zwelch> libnml could provide a wrapper around C calls, if needed... but i suppose you will explain why that isn't going to happen
[00:12:24] <paul_c> rtapi provides both policy and method - I find tha offensive from a library
[00:13:07] <zwelch> well, what if i said i'd rewrite it to give you "pluggable policy personalities"?
[00:13:47] <paul_c> the services that libnml require are provided by libc.
[00:14:09] <zwelch> * zwelch will need you to provide a little more detail about what "policy" vs "method" details you want separated
[00:14:49] <zwelch> so will the sim implementation of rtapi, right?
[00:15:06] <paul_c> library calls provide "methods" to perform a task.
[00:15:08] <zwelch> (pthreads is libpthread, but it's now part of glibc...)
[00:15:25] <paul_c> Policy is all about restrictions of those methods.
[00:15:50] <zwelch> what restrictions do you feel are imposed currently?
[00:17:06] <zwelch> most of what i've seen seems to be a bridge abstraction for implementing an API that gets implemented by several different underlying APIs
[00:17:33] <paul_c> it goes further than just rtapi, so let's not rake it over again.
[00:17:35] <zwelch> i guess what i'm offering to do is provide an even lower level access to the rtapi functions
[00:17:58] <zwelch> something that replaces the equivalent code in libnml in C, and can be used by the higher level policy functions of rtapi
[00:18:13] <paul_c> rtapi could have been implemented with a few simple macros and header files.
[00:18:22] <zwelch> still can
[00:18:27] <bpmw_> Good evening folks!
[00:19:23] <paul_c> well... That would get rid of the policy.
[00:20:27] <paul_c> I still fail to see what rtapi could possibly provide that libc doesn't already do.
[00:20:44] <paul_c> as far as libnml is concerned.
[00:24:41] <bpmw_> Does anyone know where information can be found that explains what type of linear encoders and interface hardware work with Emc2?
[00:25:28] <bpmw_> Theres just so many available i don't know what to ask for!
[00:26:10] <paul_c> You're pretty much limited to digital quadrature encoders (or scales)
[00:26:42] <paul_c> rules out the 11uA and 1V p-to-p scales.
[00:27:05] <bpmw_> Hi paul, no analog eh!
[00:27:23] <paul_c> Not unless you have cards going spare.
[00:28:08] <bpmw_> Paul, not sure what you mean?
[00:28:26] <paul_c> as for interface hardware, would suggest looking in the hal/drivers tree and see what is in there.
[00:29:21] <bpmw_> Ok I take a look, will that determine what encoders i could buy?
[00:31:09] <bpmw_> Paul, what about incremental encoders with TTl output?
[00:32:07] <paul_c> another way of saying quadrature encoder
[00:32:22] <bpmw_> ok, thanks!
[00:32:41] <paul_c> digital output covers differential & TTL
[00:33:36] <paul_c> Most of the USDigital stuff is suitable.
[00:34:37] <bpmw_> ok, this won't be an easy thing to do by the sounds of this?
[00:35:44] <paul_c> for the current status of the hal drivers, bug JMK.
[00:36:10] <zwelch> does jmk ever come on irc?
[00:36:26] <paul_c> weekends.
[00:39:15] <bpmw_> Hi Paul, Us Digitals 2 versions of linear encoders are only 1" to 2". Not much use!
[00:40:07] <paul_c> www.newall.co.uk
[00:40:46] <bpmw_> Paul I'll look there!
[00:42:42] <paul_c> It's only when you start looking at their <4um scales that the prices start looking good.
[00:43:29] <bpmw_> Paul they have two versions SHG and MHG, which one would you reccomend?
[00:44:25] <paul_c> MHG are very small if you are limited on space.
[00:45:33] <bpmw_> Paul, are they basically the same and I can make my decision based on price?
[00:45:44] <zwelch> paul_c: i also wanted to ask you about the bdi-4.27 branch; is that your work tree?
[00:46:13] <paul_c> one sec - got to update a package on the server.
[00:47:16] <zwelch> * zwelch likes to know where the other active LOD are, so he knows who to bug before making potentially conflicting changes
[00:48:32] <paul_c> bdi-4.27 is a tag for the bdi-4.2.x releases.
[00:50:54] <bpmw_> Paul sorry for all the questions but this will be a pretty major expense for me and I want to know what I buy will work!
[00:51:29] <paul_c> You want to get some quotes for the Newall stuff - It isn't cheap.
[00:51:47] <paul_c> What app is it for ?
[00:52:10] <bpmw_> I want to use it on my mill
[00:52:55] <paul_c> do you need 1um resolution ?
[00:53:15] <bpmw_> what is that?
[00:53:38] <paul_c> 0.000001 metres
[00:54:09] <bpmw_> I'd be happy with 0.0005
[00:54:24] <bpmw_> inches
[00:55:09] <bpmw_> I'm a Canadian that doesn't do metric
[00:55:22] <bpmw_> LOL
[00:55:46] <paul_c> a 20um scale in quadrature will give you a resolution of ~0.00025"
[00:56:42] <bpmw_> Thats plenty fine enough!
[00:57:07] <paul_c> 0.00019685"
[00:58:07] <paul_c> There's an outfit over in California doing cheap glass scales...
[01:00:49] <bpmw_> Paul, Newwell has two signal converters SCC-100 and SCC-200, will they interface with Emc2?
[01:02:38] <paul_c> errr... nope.
[01:03:05] <bpmw_> What do I have to look for then?
[01:06:08] <paul_c> http://www.usdigital.com/products/pci4e/ (no emc2 driver) http://www.vitalsystem.com/web/motion/motion.php (maybe a driver soon)
[01:07:12] <bpmw_> Ok Thanks!! you've been a great help!
[01:08:44] <paul_c> n.p.
[01:09:09] <bpmw_> Bye for now! have a great evening.
[01:09:51] <Jymmm> * Jymmm pokes paul_c with a 400KV cattle prod
[01:10:25] <paul_c> * paul_c looks to see who has ops.
[01:10:34] <Jymmm> me
[01:11:18] <Jymmm> whats happen paul_c?
[01:11:42] <paul_c> norra lot...
[01:12:03] <paul_c> got someone from the RTAI team bugging me for a contribution...
[01:12:35] <Jymmm> financial or development?
[01:12:54] <paul_c> development.
[01:13:24] <Jymmm> tell em when it can handle 100KHz+, you'll do it
[01:15:08] <paul_c> not even going to get 10KHz out of fusion.
[01:15:58] <Jymmm> huh? 90IPM is about 27KHz
[01:16:09] <Jymmm> 16K steps
[01:16:16] <Jymmm> 3 axis
[01:18:03] <paul_c> 38KHz @ 1um res.
[01:18:36] <Jymmm> I'm not doing 1um =)
[01:18:37] <paul_c> and 2.28m/min is pretty slow.
[01:23:33] <paul_c> damned begging letters..
[01:24:10] <Jymmm> CTRL+A;DEL
[01:26:15] <paul_c> move it to the spam folder for scanning later.
[01:27:19] <Jymmm> Ok, gots me my foil tape!
[01:27:51] <Jymmm> 10yards should be enough
[01:28:18] <paul_c> fer ?
[01:29:14] <zwelch> * zwelch just got sim_rtapi.c to compile under the new API, but now faces the same task for sim_utapi.c
[01:29:28] <Jymmm> When I was at the electronics swapmeet, I found a plastic bender heating element. You mount it to a plank, but the instructions call for two layers of foil tape as a thermal shield
[01:30:14] <Jymmm> this stuff is only 2" wide, so I'll have to double up on the width.
[01:30:35] <paul_c> zwelch: I would expect rt & usr sim to be pretty much the same code.
[01:36:41] <zwelch> paul_c: the amount of code duplication for task/mutex/shmem handling is rather staggering
[01:38:04] <paul_c> so don't duplicate then.
[01:40:22] <zwelch> nope. in fact, i've already written some code that can be re-used by all of the rtapi implementations to eliminate a bunch of common code
[01:42:06] <paul_c> that should be interesting....
[01:42:32] <zwelch> well, i don't plan to do anything outside of sim* for now
[01:42:47] <zwelch> the code can be re-used, but i'll coordinate first
[01:43:50] <zwelch> right now, i've got past the ulapi.c problems by a phenomenal amount of code use; the file now reads... '#include "rtapi.c"' :)
[01:44:16] <zwelch> erm... add sim- to that where appropriate ;)
[01:45:02] <zwelch> unfortunately, i've now realized that my Makefile hacks for building the sim need to be added to the rtapi subdirs too (e.g. examples)
[01:45:42] <zwelch> development... it's like a big text adventure game. fight past one bug only to be faced by the next one :)
[01:46:19] <jepler> zwelch: I haven't been paying much attention to this conversation, but I am interested in being able to run emc2 in simulator mode, to make sure AXIS works there. Will you post to emc-developers when there's something I can use?
[01:46:42] <jepler> "works there" means "works in emc2"
[01:46:56] <zwelch> i'll make a post as soon as i have something that works (in any reasonable capacity) for me
[01:47:01] <paul_c> #include "foo.c" is an ugly, evil hack for avoiding linking (in my opinion) and is something that should be avoided for all but exceptional cases.
[01:47:02] <zwelch> i.e. it must at least compile :)
[01:47:20] <zwelch> paul_c: it's a hack ;)
[01:47:28] <zwelch> i don't plan to commit that change
[01:47:59] <zwelch> i know what i have to do there, so i'm just looking ahead to see what other problems were lurking
[01:48:12] <zwelch> eventally, the thing will actually finish building :/
[01:50:17] <icee> well, putting source in a header file is common technique when you need inlining
[01:50:26] <icee> as not many linkers can inline code (and gnu ld isn't one of them)
[01:50:28] <paul_c> Suggestion: commit little & often - there may be others that will spot bugs that you might have missed.
[01:53:50] <paul_c> time for...
[02:27:32] <mrallen> i know this is a naive question, but if you need higher resolution, why not offload the realtime stepping control to a microcontroller?
[02:38:45] <zwelch> i think the short answer is, it would have to do everything the main CPU is doing
[02:40:54] <zwelch> of course, the real question is: if you need better resolution than what a general purpose processor can provide, why aren't you looking at existing (e.g. DSP-based) solutions? certainly, it would be cheaper to buy one of those than designing a RT "EMC offload engine" ;)
[02:43:44] <jepler> it has somehting to do with being convinced that I, or we, can do better than these existing proprietary solutoins
[02:45:28] <zwelch> the winner usually has the most resources, since translating ideas into working code takes time. closed source shops making money off their products can afford to pay programmers full-time to improve them (so they sell more, grow, etc.)
[02:46:09] <zwelch> i don't doubt open source is the better model, but i think "we win" only when we are able to produce more, faster, and for less.
[02:46:40] <icee> * icee shrugs
[02:46:47] <icee> I don't always know open source is good for the industry
[02:46:47] <icee> but
[02:47:02] <icee> producing free/open solutions does have a tendency to lower market prices and commoditize things
[02:47:26] <zwelch> that said, i believe the community needs to find funding to "win"... i.e. it has to compete in the marketplace, in order to acquire the resources required to become and stay better
[02:48:03] <icee> why? It's providing the tools for machine tool vendors to backwards integrate and stop licensing control components
[02:48:22] <icee> once it reaches a critical mass it'll be cheaper for them to integrate in what they want, rather than license.
[02:49:08] <zwelch> i agree, but my point is that "critical mass" is not fixed; it is largely dictated by existing market leaders
[02:49:20] <icee> that's not true
[02:49:27] <icee> critical mass is dictated by the use cases of the end users
[02:49:37] <icee> only to the extent that the market leaders can create and foster new use cases is that true
[02:50:23] <zwelch> right
[02:50:28] <icee> Anyways, I think the whole idea of 'winning' is superfluous
[02:50:44] <icee> i can scratch my own itch with emc; i don't care if emc takes over the industry
[02:50:57] <zwelch> in the context of the market, "winning" simply means "becoming a market leader"
[02:51:00] <icee> to the extent that it stays well supported and maintained it's in my interest
[02:51:38] <zwelch> the best way to keep an open source project vital is by having a large userbase
[02:52:07] <icee> a large userbase? more like a large number of developers using it.
[02:52:12] <zwelch> and in a vertical market, that means taking marketshare from existing players, which means competing with them for their users
[02:52:45] <zwelch> well, once there is a large user base, then there is demand for developers... who can supply their services at the going market rate
[02:53:04] <icee> perhaps, perhaps not.
[02:53:08] <zwelch> * zwelch shrugs
[02:53:18] <icee> there's friction in the market that prevents end users of solutions like this from directly employing developers to solve problems
[02:53:27] <icee> e.g. they don't have the expertise to spec and manage the project and to hire well.
[02:53:53] <zwelch> then that becomes the developer's responsibility
[02:54:21] <icee> I think the model you're looking at isn't how open source has been adopted in vertical markets
[02:55:22] <icee> What happens is a die hard cadre of a few users builds a solution to solve a hobbyist problem, and the project grows attracting only technical users; then, someone who is licensing IP realizes they can instead just use the open source solution; they have experience developing and integrating so they can manage a project and integrate it into their product.. and that's how you get critical mass.
[02:56:25] <icee> e.g. what uclinux has done in the low ends of the rtos space, or the high end server market with linux, etc.
[02:57:18] <icee> and to an extent what we see happening with emc and sherline and a few other low end tool vendors
[02:58:15] <icee> or what i see starting to happen with mythtv in my exposure to semiconductors
[02:59:40] <zwelch> so you don't want to actually do anything, just sit around and wait for this magical "critical mass" to just happen, eh?
[03:00:06] <zwelch> you don't think there's any room for "grabbing the bull by the horns", so to speak?
[03:00:22] <icee> what difference does it make to me whether EMC reaches that critical mass?
[03:00:41] <icee> it's not worth me spending my development time to fix problems that i don't have
[03:01:20] <mrallen> i guess my question was along the lines of: i already have to buy substantial hardware to get this going (pc, steppers, stepper drivers) .. why not another $100 for a little micro and logic board to offload the hard real time stuff
[03:01:54] <icee> mrallen: because rtlinux is already pretty good for the step rates you get on a small installation?
[03:01:55] <mrallen> i have done a bit of micro development (wrote my own rt scheduler for Atmel AVR) in assembly
[03:02:20] <icee> the parallel port under rtlinux is good to over a hundred kilohertz
[03:02:24] <mrallen> i could do an open source AVR driver + schematics that could put all the hard real time stuff on a 3x2 board
[03:02:32] <icee> on the AVR, that gives you less than 16 cycles
[03:02:57] <icee> to choose what you're going to do and stick it out GPIO to match the parallel port.
[03:02:59] <mrallen> 160 cycles
[03:03:09] <icee> er. my bad. math is hard ;)
[03:03:20] <mrallen> 200 cycles on 20mhz versions
[03:03:21] <icee> and you could maybe use the timer counters but that would get tricky
[03:03:33] <icee> if you wanted to do this, why not use something like tms320f2810?
[03:03:41] <mrallen> because i don't know it :)
[03:03:55] <icee> well, that's what the commercial solutions use, and for good reason
[03:04:20] <icee> unless you're going to do the math on accelerating axes, etc, in the realtime controller, it's not a big win.. and AVR isn't studly enough for that at reasonable step rates
[03:04:38] <icee> and really, maybe AT91 would be.. but use the right tool for the job.
[03:04:52] <mrallen> i wouldn't imagine offloading everything
[03:05:12] <icee> mrallen: what real-world performance advantage would you hope to get?
[03:05:19] <mrallen> but set up a com channel feeding pre-digested bits to the micro ... it would do make sure it executed at hte
[03:05:50] <zwelch> mrallen: the problem is that the "bits" take into account feedback from the system (right?)
[03:06:00] <mrallen> icee: really don't know. i'm not familiar enough with the low levels of emc
[03:06:19] <icee> rtlinux is pretty good, and the parallel port is acceptable.
[03:06:44] <zwelch> you can't just generate a bit stream and deliver it in real-time; you may have to be re-calculating things based on feedback from the system - in real-time
[03:06:44] <mrallen> zwelch: as i said, i have a naive view of this. i picked up on the comments above from paul that it couldn't move fast enough due to RT limitations
[03:07:19] <zwelch> right, and to use EMC "offloading", you'd have to port EMC to the actual target embedded hardware and run rtlinux on it :)
[03:07:20] <mrallen> thanks for the clarifications, though.
[03:07:33] <mrallen> zwelch: that would suck
[03:07:36] <zwelch> then you just run emc over ssh over usb ;)
[03:07:49] <zwelch> i.e. run emc on a gumstix
[03:08:00] <zwelch> then the gumstix is the RT computer
[03:08:07] <zwelch> and a USB peripheral
[03:08:32] <zwelch> but you'd have to build a board to drive the hardware that interfaces with it
[03:09:00] <icee> exactly what limitations was paul speaking of? because i didn't see it
[03:09:07] <zwelch> * zwelch didn't either
[03:09:20] <zwelch> he didn't exactly answer my question
[03:09:38] <zwelch> the only thing i remember was... "gotta tune stuff" or something
[03:09:53] <zwelch> vague, yet unhelpful :)
[03:16:38] <icee> http://pico-systems.com/univstep.html
[03:16:46] <icee> if you really want a microconrtoller board.
[03:17:23] <icee> looks like they went with a FPGA to implement it
[03:20:17] <Jacky^> * Jacky^ ywnssssss
[03:44:23] <Jacky^> goodnighttt
[03:51:05] <jcolley> greets guys
[03:51:09] <jcolley> jcolley is now known as siado
[03:55:05] <siado> is it possible to use dual loop feedback using linear encoders on slide position and rotary encoders on the servo shaft with the Vital card?
[04:22:28] <jepler> icee: incidentally, I did a quad step+dir to phase drive (is this the right term? 4 outputs, 1 or 2 on at a time) on 16MHz AVR. It was fast enough to 48000 steps per second per axis, but I'm not sure how much faster than that it would have gone.
[04:22:51] <jepler> er, I probably mean 9600 steps per second per axis
[04:23:23] <jepler> this is atmega32, triggering interrupts on each DIR pulse (you can configure the timer inputs to act like external interrupts)
[04:23:37] <jepler> atmega16 would have worked too
[04:24:06] <jepler> but I just don't think there's time to do anything much more sophisticated than that
[05:48:14] <Jymmm> jepler: what KHz would that be?
[06:12:12] <ValarQ> morning folks
[06:12:45] <Jymmm> [21:49:33] <ValarQ> morning folks =)
[06:13:09] <ValarQ> 06:49 < Jymmm> [21:49:33] <ValarQ> morning folks =)
[06:21:34] <Jymmm> Allthese huricanes are bugging me...
[06:21:56] <ValarQ> were do you live?
[06:22:42] <Jymmm> Calif, just the principal. FEMA says NY, New Orleans, then San Francisco, which I'm 40 minutes from.
[06:23:09] <Jymmm> and that was in 2004
[06:23:37] <ValarQ> FEMA?
[06:23:42] <Jymmm> It's been almost 100 years, so a big earthquake to brewing.
[06:23:57] <Jymmm> FEAM == Federal Emergency Management Adminitration
[06:24:02] <Jymmm> FEMA
[06:24:06] <ValarQ> ok
[06:24:32] <Jymmm> The federal agency that does disaster mgnt stuff
[06:38:19] <Jymmm> I have some disaster suppplies, but as much as I would feel comfortable with.
[06:46:34] <zwelch> so i actually just managed to get emc2 to build without RT bits
[06:46:55] <zwelch> however, i almost immediately discovered they don't work :)
[06:48:47] <zwelch> * zwelch tosses those bits in the round filing bucket and begins to stalk his elusive prey: "buggus rutimeous"
[09:16:57] <anonimasu> :D
[11:25:39] <anonimasu> hello
[11:25:45] <anonimasu> paul_c: got a sec?
[11:27:31] <paul_c> urrrmm ?
[11:43:37] <anonimasu> hm, I have a question about jog wheel
[11:43:38] <anonimasu> s
[11:46:00] <paul_c> Ask, and I'll see if I can answer it.
[11:46:31] <anonimasu> would it be possible to modify the USC driver so that I could use one of the counters as input for a jog wheel
[11:47:13] <paul_c> I don't see why not.
[11:47:53] <anonimasu> and, how well does the bdi version of emc2 with the usc driver work?
[11:48:06] <paul_c> Wouldn't limit it to just te USC... Make the same change on the other drivers, and you'd have jog wheels on all of them.
[11:48:51] <anonimasu> hm, yeah
[11:48:56] <anonimasu> maybe I should have a look at it
[11:49:03] <anonimasu> being without jog wheel is a hassl
[11:49:04] <anonimasu> e
[11:49:06] <paul_c> I don't have any of Jon's hardware... All I can say is the driver works.
[11:49:28] <paul_c> just look at the recent emc-user postings
[11:49:47] <anonimasu> why?
[11:50:04] <anonimasu> to see if it works?
[11:50:09] <anonimasu> I am not too happy with emc1..
[11:50:18] <anonimasu> so it's probably lots better
[11:50:21] <paul_c> confirms USC works for one user at least.
[11:50:31] <anonimasu> the fact that it uses the max accel for rapid moves on all axis:es..
[11:50:44] <anonimasu> my stepper on z goes whirr when I move it..
[11:50:46] <anonimasu> on rapids..
[11:51:59] <paul_c> there is no USC driver for emc2
[11:52:23] <anonimasu> didnt you say there were before?
[11:52:28] <anonimasu> in the bdi version?
[11:52:42] <paul_c> JMK started on the framework of one at the codeFest, but that was as far as it got.
[11:53:15] <anonimasu> :/
[11:53:17] <paul_c> the BDI-4 drivers are EMC1.
[11:53:30] <anonimasu> damn.
[11:53:37] <anonimasu> well, the usc works great..
[11:53:41] <anonimasu> emc does not.. :/
[11:54:28] <paul_c> you think emc2 is going to be any better ?
[11:55:13] <anonimasu> paul_c: remember that I've been making lots of parts with emc2..
[11:56:10] <anonimasu> emc1 would work good if it werent for the fact that it dosent limit the accel of my Z for some reason
[12:00:39] <paul_c> weren't you having "issues" with the tkemc buttons in emc2 ?
[12:01:38] <anonimasu> in emc1 also..
[12:02:00] <anonimasu> if I remember it right..
[12:10:34] <anonimasu> :)
[13:26:45] <Jacky^> hey bosone
[13:26:52] <anonimasu> hm
[13:26:54] <anonimasu> hello jacky
[13:27:00] <Jacky^> hi anonimasu :)
[13:28:57] <anonimasu> how's things going?
[13:29:19] <Jacky^> here, rain ..
[13:29:33] <Jacky^> looking for inexpensive servo driver
[13:29:39] <anonimasu> geckos?
[13:29:44] <Jacky^> i found an interesting chips
[13:29:54] <Jacky^> no, not gecko
[13:29:54] <anonimasu> what's wrong with geckos?
[13:30:00] <Jacky^> the price..
[13:30:16] <Jacky^> and the controller needed for encoders etc..
[13:30:23] <anonimasu> controller?
[13:30:29] <anonimasu> you dont need any controller with geckos
[13:30:48] <anonimasu> you feed them step & dir just as you would with stepper drivers
[13:30:52] <Jacky^> where the encoders are connected ?
[13:30:56] <anonimasu> into the gecko..
[13:30:59] <Jacky^> to the driver ?
[13:31:05] <anonimasu> they have the pid loop internally
[13:31:15] <Jacky^> uhm..
[13:31:35] <Jacky^> total control to the driver, minimal to emc so ..
[13:31:58] <anonimasu> well price/performancewise you wont beat them..
[13:32:11] <anonimasu> yep
[13:32:16] <Jacky^> i'm looking at pic-servo
[13:32:23] <Jacky^> theres an interesting chip
[13:32:36] <anonimasu> if you feel like building something build a pulse generator
[13:32:41] <anonimasu> for using with geckos :)
[13:32:46] <Jacky^> but an rs232 controller is needed
[13:32:57] <anonimasu> btw, why are you looking at servos when you cant afford cheap servodrives?
[13:33:10] <anonimasu> or are you going to ignore inertia and just use cheap dc motors?
[13:33:11] <Jacky^> for 2 reasons
[13:33:27] <Jacky^> first, i want to start to play around servomotor
[13:33:29] <anonimasu> you know good encoders are $150..
[13:33:32] <anonimasu> or well ok ones..
[13:33:35] <Jacky^> without spend a lot of money
[13:34:00] <Jacky^> second, my cousin is interesting in build a machine for his plasma cutter
[13:34:07] <Jacky^> using servos..
[13:34:36] <Jacky^> anonimasu: i found some nice encoder for just $ 19
[13:34:42] <anonimasu> how nice is nice`?
[13:34:45] <anonimasu> 2000cpr?
[13:34:58] <Jacky^> mmhh cant remember the resolution
[13:35:11] <Jacky^> but it could be enough for me
[13:35:19] <Jacky^> searhcink the link ..
[13:35:40] <anonimasu> ok
[13:35:47] <Jacky^> http://www.usdigital.com/products/e4p/
[13:36:00] <Jacky^> # 120 to 300 cycles per revolution (CPR)
[13:36:01] <Jacky^> # 480 to 1200 pulses per revolution (PPR)
[13:36:26] <Jacky^> 2 channel quadrature TTL squarewave outputs
[13:37:10] <Jacky^> i cant start buyng encoders of $ 150 each :\
[13:37:58] <Jacky^> also, ill use surplus motors ..
[13:38:45] <Jacky^> i hope done it with about E. 350-400
[13:38:58] <Jacky^> excluding motors
[13:39:44] <Jacky^> but i need to check for shipping cost, tax, etc ..
[13:39:51] <Jacky^> before to buy
[13:40:03] <anonimasu> g101 is selling now
[13:40:04] <anonimasu> :)
[13:40:14] <Jacky^> how much ?
[13:40:20] <anonimasu> 208$
[13:40:28] <anonimasu> and 135$ for the breakout board
[13:40:33] <Jacky^> 20 A 80 V ?
[13:40:45] <anonimasu> you still need drives.
[13:41:49] <anonimasu> a g340 costs 148$
[13:42:15] <Jacky^> if understood ok, they are just amp ?
[13:42:20] <anonimasu> yes
[13:42:40] <Jacky^> what other is needed ?
[13:42:46] <Jacky^> breakout board
[13:42:49] <anonimasu> no
[13:42:50] <anonimasu> nothing
[13:43:00] <anonimasu> but it depends if you want to use software generated pulses..
[13:43:03] <anonimasu> step&dir..
[13:43:19] <anonimasu> or hardware generated like from a usc
[13:43:21] <anonimasu> or g101
[13:43:21] <Jacky^> i would like to use emc, of course
[13:44:03] <Jacky^> paul_c: sayd servos module has step, dir and encoder quadrature control
[13:44:10] <Jacky^> in emc
[13:44:28] <anonimasu> when you use geckos you arent using the servo module, for emc but stepgen..
[13:44:33] <Jacky^> maybe also PID could be controlled by emc
[13:44:36] <anonimasu> or freqmod..
[13:44:45] <Jacky^> oh ..
[13:44:49] <Jacky^> like stepper
[13:44:52] <anonimasu> yeah..
[13:44:56] <Jacky^> right
[13:45:00] <anonimasu> but the geckos takes care of the pid loop for each servo..
[13:45:09] <Jacky^> it working stepper-like whit step-dir
[13:45:18] <anonimasu> yeah
[13:45:18] <Jacky^> the driver do all the rest
[13:45:40] <Jacky^> so.. the jecko can be connected to the parport
[13:45:47] <anonimasu> yes..
[13:45:51] <Jacky^> nice
[13:45:56] <anonimasu> like normal stepper drives..
[13:46:09] <Jacky^> i want to calculate anything now
[13:46:15] <Jacky^> about thefinal cost
[13:46:22] <anonimasu> if you need more speed you can get a usc..
[13:46:24] <Jacky^> if the difference isnt too much
[13:46:27] <anonimasu> or build a pulse generator
[13:46:36] <anonimasu> 148*2 for the x&y axis..
[13:46:38] <Jacky^> id be inclined for gecko
[13:46:42] <anonimasu> you wont need a servo for the Z..
[13:47:10] <anonimasu> there are a cheaper ver g320 but you wont have the pulse multiplier there..
[13:47:30] <anonimasu> and you defenetively want it :)
[13:47:35] <Jacky^> ive seen something
[13:47:43] <anonimasu> and motors + encoders
[13:47:44] <Jacky^> ok.. i must go now
[13:48:03] <Jacky^> i'm going with a friend to help him in the first dsl installation ..
[13:48:06] <Jacky^> :\
[13:48:08] <anonimasu> :/
[13:48:08] <Jacky^> later..
[13:48:10] <anonimasu> yep
[13:48:11] <Jacky^> bye
[15:54:57] <Jymmm> aefully quiet in here this morning
[15:55:25] <anonimasu> yes
[15:56:06] <anonimasu> got a replacement part yet?
[15:56:14] <Jymmm> nope
[15:56:46] <anonimasu> :/
[15:56:55] <anonimasu> arent you anxious to start to cut parts?
[15:56:57] <anonimasu> making stuff
[15:57:06] <Jymmm> of course
[16:00:45] <Jymmm> "It's very difficult to soar with the Eagles when you're working with turkeys"
[16:02:08] <anonimasu> heh
[16:02:10] <anonimasu> ^_^
[16:11:33] <Jymmm> I've been looking at some flashlights the last couple weeks... big variety out there
[16:13:05] <Jymmm> Mostly LED based, trying to avoid the specialized batteries
[16:14:11] <Jymmm> I found a single AA one with 10 hour battery life, but the reviews say the beam shape is not very desirable.
[16:14:56] <Jymmm> $20 USD http://www.flashlightreviews.com/reviews/inova_x1.htm
[16:16:30] <Jymmm> This one is on sale for $40 USD, but uses litium batteries and only a 1-2hr life. http://www.flashlightreviews.com/reviews/inova_xo3.htm
[16:32:43] <anonimasu> :/
[17:39:55] <jepler> paul_c: on 4.29, AXIS works for us, the problems we attributed to the FP bug are gone. http://axis.unpy.net/index.cgi/01127491762
[17:40:52] <jepler> Jymmm: did you ever find out if updating emc fixed your problems with axis crashing
[17:40:53] <jepler> ?
[17:42:15] <alex_joni> greetings all
[17:42:20] <jepler> hi alex
[17:43:28] <alex_joni> hi there
[17:43:30] <alex_joni> what's up?
[17:43:48] <jepler> bdi 4.29 seems to fix the problems we were seeing with axis back in 4.25
[17:44:05] <alex_joni> * alex_joni recalls reading smthg like that in the logs
[17:44:27] <alex_joni> glad to hear it's ok now
[17:44:31] <jepler> me too
[17:47:18] <cradek> me too
[17:48:18] <alex_joni> heh
[17:48:27] <alex_joni> grouphug
[17:48:31] <alex_joni> ROFL ;)
[17:53:43] <alex_joni> supper time
[17:53:47] <alex_joni> catch you later
[18:10:27] <Jymmm> jepler: Yes it did fix the segfault. I was also able to lick up the system too =)
[18:10:32] <Jymmm> lock
[18:11:54] <jepler> you mean, it locks up with 4.29, or it did lock up with an older release?
[18:13:27] <Jymmm> Well, I was never able to use axis at all previously. After I updated the kernel and what not and got axis up and going. I was mucking around with axis and locked up the system. Finally was able to exit axis, but couldn't even kill -9 the background emc tasks that were running.
[18:17:00] <Jymmm> jepler I did have a question.... Does axis "falback" on the gl stuff if it can't keep up on older video HW ?
[18:17:05] <Jymmm> fallback
[18:46:27] <robin_z> meep?
[18:48:48] <Jacky^> hey robin_z
[18:50:48] <Jacky^> what the advanage of a pulse multiplier on a servodrive ?
[18:51:19] <Jacky^> i'm looking at gecko G340 ..
[19:14:12] <anonimasu> it allows you to scale down high res encoders
[19:14:25] <anonimasu> so you get more speed..
[19:14:49] <Jacky^> good
[19:15:43] <Jacky^> i'm a little confused about the encoders..
[19:15:50] <Jacky^> using emc
[19:16:13] <Jacky^> it seem geckodrive has internal control fo encoders right ?
[19:16:32] <anonimasu> you are not involving emc in the pid loop at all
[19:16:58] <anonimasu> brb..
[19:17:02] <anonimasu> going away to a friend
[19:17:03] <Jacky^> so, emc will not check the quadrature encoder ..
[19:17:08] <Jacky^> ok
[19:17:19] <Jacky^> bye
[19:38:21] <Jymmm> Jacky^: I forget, what is the travel on your machine?
[19:39:27] <Jacky^> actually is about 30 cm
[19:39:54] <Jacky^> but i'm asking for drivers to use on a new machine
[19:40:03] <Jacky^> not this i've now..
[19:58:51] <alex_joni> hello
[19:59:04] <Jacky^> hi alex_joni
[19:59:11] <alex_joni> hey Jacky^
[20:23:17] <alex_joni> hey Martin
[20:35:04] <Jacky^> what abut encoders connection to emc ?
[20:35:33] <Jacky^> if drive like gecko are used it seem no coonecion needed
[20:35:56] <Jacky^> but how can emc know if an error occour ?
[20:35:57] <alex_joni> right
[20:36:05] <alex_joni> there is an error pin on the gecko
[20:36:12] <alex_joni> you can use that as estop in to emc
[20:36:14] <Jacky^> emc, in this case cant do nothing
[20:36:23] <Jacky^> oh..
[20:36:24] <alex_joni> but best would be to have the encoder conected to emc too
[20:36:27] <alex_joni> * alex_joni tried that
[20:36:32] <Jacky^> error pin ?, i've seen
[20:36:50] <alex_joni> but if you want a proper solution
[20:36:50] <Jacky^> this pin should be connect to parport ?
[20:36:50] <alex_joni> use an USC
[20:37:06] <Jacky^> like motenc ?
[20:37:16] <alex_joni> iirc the USC has the possibility to take care of encoders properly, even if the gecko errors
[20:37:22] <alex_joni> the one JonE sells
[20:37:44] <Jacky^> never seen ..
[20:37:51] <Jacky^> got a link ?
[20:38:23] <alex_joni> http://pico-systems.com/univstep.html
[20:40:23] <Jacky^> with this board emc can take the control on quadrature encoders i suppose
[20:41:02] <alex_joni> sure
[20:41:25] <alex_joni> one small problem ;)
[20:41:30] <alex_joni> no emc2 driver yet
[20:41:48] <Jacky^> uhm.. ok
[20:43:17] <anonimasu> hello
[20:43:24] <alex_joni> hey anders
[20:43:27] <Jacky^> hi anonimasu
[20:43:37] <anonimasu> alex_joni: how's things?
[20:45:03] <alex_joni> pretty nice
[20:45:09] <alex_joni> going home tomorrow
[20:47:47] <alex_joni> anonimasu: how about you?
[20:48:28] <anonimasu> not too great
[20:48:38] <anonimasu> havent been to work today
[20:49:05] <alex_joni> sick?
[20:49:16] <alex_joni> or.. sick of it ;)
[20:49:39] <anonimasu> woke up and couldnt get out of bed.
[20:50:00] <alex_joni> too bad :(
[20:50:12] <anonimasu> yeah
[20:50:12] <alex_joni> btw, I'm coming to sweden ;)
[20:50:20] <anonimasu> yeah you told me about that earlier
[20:50:21] <anonimasu> :)
[20:51:08] <alex_joni> will be the 8th country in 2 months :))
[20:51:18] <anonimasu> :D
[20:51:24] <Jymmm> alex_joni Just as long as you stay in .eu!
[20:51:39] <anonimasu> ince
[20:51:43] <alex_joni> I usually am outside ;)
[20:51:49] <alex_joni> so I don't actually care
[20:52:47] <Jymmm> alex_joni: No, stay in Europe that is!
[20:53:29] <alex_joni> Jymmm: where else should I go?
[20:53:42] <Jymmm> alex_joni Antartica
[20:53:46] <alex_joni> nothing interesting there
[20:54:03] <Jacky^> alex_joni: if not USC used, G320 can work fine the same on emc ?
[20:54:17] <alex_joni> yup
[20:54:32] <anonimasu> yes.
[20:54:44] <Jymmm> alex_joni Can you feel the love?
[20:55:19] <alex_joni> Jymmm: melting my heart
[20:55:35] <Jymmm> lol
[21:02:43] <Imperator_> Hi Alex, hi all
[21:03:58] <alex_joni> what's new Martin?
[21:05:18] <Imperator_> hm, still working on the breakout boards for the mesa card
[21:06:16] <Imperator_> the io board ready, and waits for the components
[21:07:03] <Imperator_> i hope to finish teh DAC and encoder board as well this weekend
[21:07:08] <Imperator_> the
[21:07:59] <Jymmm> mesa card?
[21:08:12] <Jymmm> beakout board?
[21:08:16] <Imperator_> www.mesanet.com
[21:08:32] <Jymmm> oh, that.
[21:08:33] <Imperator_> 5i20 pci anythin io card
[21:08:39] <Jymmm> are you programming it yourself?
[21:08:53] <Imperator_> first i need the hardware
[21:09:03] <Jymmm> they're 40 minutes from me.
[21:09:20] <Imperator_> 8 hours i think
[21:09:51] <Jymmm> what pulerate can you get out of it and how many axis?
[21:10:45] <Imperator_> pulerate ??
[21:10:52] <Jymmm> pulse rate (KHz)
[21:11:29] <alex_joni> that's PR ;)
[21:11:31] <Imperator_> i want to controll servos, so i'm away from this puls rate question
[21:11:45] <Jymmm> ah
[21:12:10] <Imperator_> we are two gys here in germany working on that suff
[21:12:56] <Imperator_> we are making some breakoutboards, to read encoders, and to give out a +-10V signal for the servos, and for the io stuff
[21:14:46] <Jymmm> personal or production use?
[21:16:08] <Imperator_> i need it for a machine, that one is for production
[21:16:27] <Jymmm> ok, when you get 99.999999% ready to release, send over 10,000 cases and I'll beta test them for you =)
[21:16:49] <Imperator_> ok
[21:17:08] <Imperator_> or i send you the files, then you can make it by ureself
[21:17:20] <Imperator_> youreself
[21:17:32] <Jymmm> no, not will never do...
[21:17:47] <Jymmm> I have to maintain my lazy status =)
[21:18:12] <Imperator_> :-)
[21:18:35] <Imperator_> maybe we will sell some, but that is not our focus
[21:18:53] <Jymmm> though, you could get some boards made and sell tham as a kit.
[21:19:40] <Jymmm> screw that, seel them. I'm sure more than one person out would like an alternative ready to go.
[21:19:42] <Jymmm> sell
[21:19:54] <Jacky^> what is a DRO ?
[21:20:05] <Jymmm> you could sell just the boards, and let them buy/stuff the components.
[21:20:13] <Jymmm> Diital ReadOut
[21:20:18] <Jymmm> Digital Read Out
[21:20:22] <Jacky^> thanks
[21:20:24] <Jymmm> np
[21:20:56] <Jymmm> Imperator_ shipping would be easy too for a flat PCB
[21:21:17] <Jacky^> alex_joni: this USC is veri interesting, i like hoe it work :D
[21:21:20] <Imperator_> the problem is that if we sell them we must support the cusomors, so maybe it is better to sell them only to some well known people
[21:21:25] <LawrenceG> Imperator_, good afternoon
[21:21:32] <alex_joni> Jacky^: ask anonimasu, he has one iirc
[21:21:34] <Imperator_> Hi Lawrance
[21:21:45] <Jacky^> alex_joni: thanks
[21:21:57] <LawrenceG> Imperator_, I am very intersted in a bare pcb if you are having some made
[21:22:02] <Jymmm> Imperator_ no it doesn't.... just do like everyone else does... yahoo groups for (free) support.
[21:22:18] <Jymmm> Imperator_: See, your first customer.
[21:22:24] <Imperator_> Jymmm: if we sell only pcbs to everyone we will have only trouble, i think
[21:22:29] <Jymmm> Imperator_ gimme my 10% finders fee bitch!
[21:22:49] <Jymmm> Imperator_ Not if you document it well.
[21:22:51] <Imperator_> hehe
[21:23:03] <Jymmm> it's just a breakout board (passive), isn't it?
[21:23:14] <Imperator_> yes
[21:23:35] <Imperator_> we will set the stuff under GPL if it is finished
[21:23:50] <Jymmm> then np. If someone is using an anything card, they should have the technical skill to solder header connectors.
[21:23:56] <Imperator_> maybe we wil sell some, we will see
[21:24:01] <LawrenceG> Imperator_, to clock the signals into the dacs, I assume you are planning an emc 2 fpga mod?
[21:24:40] <Imperator_> how do you mean that Lawrence ?
[21:25:01] <LawrenceG> how are you planning to write the drive values to the dacs?
[21:25:15] <Imperator_> that are 16bit words
[21:25:39] <Imperator_> its a quad DAC DAC7744
[21:26:18] <LawrenceG> yes... but are you using the fpga to send parallel or serial data to the dac?
[21:26:45] <Imperator_> parallel
[21:26:59] <Imperator_> ther is a other one with a serial interface
[21:27:07] <Imperator_> DAC7743 i think
[21:27:32] <LawrenceG> ok... no problem... I assumed you were using a high speed serial interface with "16 bit uarts" in the fpga
[21:28:16] <LawrenceG> I'll take another look at the interface on the data sheet
[21:28:23] <Imperator_> parallel is much more simple
[21:30:14] <LawrenceG> I was thinking one could reuse the pwm and dir lines and do an fpga config so that a single 16 bit wirte to the fpga would cause the data to be sent to the appropriate dac registers
[21:31:35] <LawrenceG> Imperator_, can you please send me an updated eagle project? (ve7it at shaw dot ca)
[21:33:33] <pc_op`> pc_op` is now known as pc_op
[21:36:34] <Imperator_> maybe we go one step ahead and let the FPGA do the PID stuff
[21:44:36] <LawrenceG> the fpga does have one config that includes a processor option that does do complete servo in th fpga
[21:45:33] <LawrenceG> I would be very happy to let emc do the servo (easier config changes) and just have hardware registers that one read a 32bit position and wrote a 16 bit drive word
[21:52:49] <Imperator_> ah, i got the message that the IO board is working now
[21:54:39] <alex_joni> night guys
[22:45:28] <robin_sz> meep?
[22:45:45] <Jacky^> hey robin_sz
[22:45:47] <ValarQ> woo
[22:45:52] <robin_sz> hi Jacky^
[22:45:57] <Jacky^> hello ValarQ
[22:46:00] <robin_sz> are you well?
[22:46:10] <anonimasu> hello
[22:46:14] <Jacky^> 50 % well ..
[22:46:21] <Jacky^> the rest is baaaad
[22:46:23] <Jacky^> :\
[22:46:24] <ValarQ> 'lo anon
[22:46:28] <robin_sz> oh fooey
[22:46:34] <robin_sz> how bad?
[22:46:47] <Jacky^> another driver burned
[22:46:51] <robin_sz> heh
[22:47:00] <Jacky^> stopped again ..
[22:47:01] <robin_sz> one word.
[22:47:04] <robin_sz> gecko.
[22:47:10] <Jacky^> :(
[22:47:29] <Jacky^> i'm right thinking it
[22:47:49] <ValarQ> what is this gecko thingie you folks always talk about?
[22:48:16] <Jacky^> im thinking the G340 ..
[22:48:24] <robin_sz> geckodrive.com maker of cheap and good stepper drives
[22:48:35] <Jacky^> I know ..
[22:48:40] <robin_sz> Jacky^: servos? just use emc and do it properly
[22:48:51] <anonimasu> robin_sz: $$$$
[22:49:01] <Jacky^> i also seen the USC by picosystem
[22:49:02] <ValarQ> robin_sz: cheap and good?
[22:49:09] <Jacky^> i like it
[22:49:15] <robin_sz> ValarQ: geckos? yeah cheap and very good
[22:49:23] <ValarQ> ok
[22:49:38] <Jacky^> i dont know how accurate will be the encoders control by gecko
[22:49:41] <robin_sz> Jacky^: yeah, if you wanna drive steppers with emc, you'll need that
[22:50:06] <Jacky^> no, not stepper
[22:50:11] <Jacky^> i'm thinking servos
[22:50:24] <Jacky^> im tired with stepper
[22:50:48] <Jacky^> the only test i will do, if ive time.., will be to addencoders to stepper
[22:50:58] <Jacky^> as we talked some mouth ago ..
[22:51:15] <Jacky^> but i want to use DC motors
[22:52:06] <Jacky^> i wonder what happening ,, if a big error on quadrature occour on gecko
[22:52:16] <Jacky^> if undestood well, it will go in fault
[22:52:20] <anonimasu> 9yep
[22:52:32] <anonimasu> if you end up that far away your machine is _wron_
[22:52:36] <anonimasu> _wrong_
[22:52:52] <anonimasu> I've never had a gecko trip when I didnt accel it way too much
[22:53:26] <robin_sz> Jacky^: for plasma?
[22:53:30] <Jacky^> this.. would replicate the same problem ive with the steppers now ..
[22:53:38] <Jacky^> robin_sz: yes, plasma cutter
[22:53:42] <anonimasu> Jacky^: no, the pid loop would catch up..
[22:53:45] <robin_sz> how big?
[22:53:48] <anonimasu> if you get any deviation..
[22:54:04] <anonimasu> Jacky^: if you get larger deviation your motors are too small..
[22:54:17] <Jacky^> robin_sz: to cut flanges
[22:54:19] <anonimasu> or there's something in the way..
[22:54:32] <Jacky^> 1-1,5 mt
[22:54:34] <robin_sz> Jacky^: how big is the machine you want to build?
[22:54:52] <robin_sz> 1m x 1.5m?
[22:54:53] <Jacky^> 1.5 mt should be enough
[22:55:03] <Jacky^> probably 1x1
[22:55:15] <robin_sz> 1x1 is steppers in my opnion
[22:55:25] <Jacky^> to remain in a low cost machine
[22:55:47] <Jacky^> robin_sz: I know ..
[22:55:49] <robin_sz> what are you going to do for torch height control?
[22:56:03] <Jacky^> but my cousin absloute dont want to use steppers..
[22:56:14] <robin_sz> why is that?
[22:56:54] <Jacky^> robin_sz: i dont know what he exactly want do ..
[22:57:09] <Jacky^> the oly thing he sayd he dont like steppers
[22:57:16] <anonimasu> Jacky^: larger steppers is the solution to the missed step problem.
[22:57:20] <robin_sz> well, you want my advice?
[22:57:33] <Jacky^> robin_sz: sure
[22:57:47] <robin_sz> leave him to get on with it. ask him to give you a phone call when its finished
[22:57:57] <Jacky^> anonimasu: i need very high speed for woodwirking
[22:58:10] <Jacky^> too many pass at high speed
[22:58:11] <anonimasu> Jacky^: machine rigitity.
[22:58:32] <robin_sz> Jacky^: define high speed
[22:58:44] <Jacky^> robin_sz: he build amachine 3 years ago ..
[22:58:53] <Jacky^> to mill steel plate
[22:58:58] <anonimasu> with a router?
[22:58:59] <Jacky^> 5 cm thickness
[22:59:04] <Jacky^> router ?
[22:59:12] <Jacky^> no motor.. 380 V
[22:59:21] <Jacky^> he used DC motor with encoder
[22:59:32] <Jacky^> and some primitive driver
[22:59:46] <robin_sz> ah look, we did this conversation last week ... a small 1mx1m plasma is perfect for steppers. no missed steps
[22:59:47] <Jacky^> he was only swicthing from 12 V to 5 V the motors
[22:59:56] <anonimasu> um..
[23:00:08] <anonimasu> are you aware that 12v motors are toy motors..
[23:00:08] <Jacky^> I know ..
[23:00:09] <robin_sz> using servos will give you many more problems on a plasma
[23:00:18] <anonimasu> suitable for rc cars..
[23:00:19] <Jacky^> probably new nema 34 are ok
[23:00:25] <robin_sz> yep
[23:00:29] <anonimasu> unless they are 12v 20a
[23:00:29] <robin_sz> and good drives
[23:00:32] <Jacky^> but he dont like it steppers..
[23:00:41] <robin_sz> well, let him build it then
[23:00:53] <Jacky^> anyway
[23:01:02] <Jacky^> i need to start building a new machine
[23:01:10] <Jacky^> not the toy ive now ..
[23:01:30] <anonimasu> Jacky^: what machine is built to mill 5cm plate?
[23:01:32] <anonimasu> is it a router?
[23:01:53] <Jacky^> anonimasu: i know he used a big AC motor
[23:01:58] <robin_sz> does he know *anyhting* about building plasma with servo? ...
[23:01:59] <Jacky^> probably homebuild
[23:02:05] <anonimasu> Jacky^: was it a router?
[23:02:15] <Jacky^> anonimasu: I suppose so ..
[23:02:17] <robin_sz> Jacky^: you know how servo works, with an encoder?
[23:02:34] <Jacky^> robin_sz: i've an half idea..
[23:02:45] <robin_sz> Jacky^: you know how a plasma torch is ignited with about 2Kv of RF?
[23:03:21] <Jacky^> robin_sz: nope.. i' dont know anything about plasma cutter ..
[23:03:44] <Jacky^> he only sayd it work with high voltage and air ..
[23:03:56] <Jacky^> he sayd have seen these cutter working
[23:04:01] <Jacky^> with cnc
[23:04:05] <robin_sz> well, to ignite the arc, they use about 2kv of RF ... it has two uses ... one is to ignite the arc, the second is to destroy any electronics it can find
[23:04:09] <Jacky^> cutting steel
[23:04:10] <anonimasu> they generate LOTS OF RF interference..
[23:04:14] <robin_sz> yep
[23:04:15] <anonimasu> pilot arc..
[23:04:18] <robin_sz> yep
[23:04:22] <robin_sz> so ...
[23:04:33] <anonimasu> they are a bit better, but the cheap/older plasmas kills stuff even faster
[23:05:03] <Jacky^> you mean this can disturb the regular work of drivers ?
[23:05:08] <robin_sz> if you can afford to build it two or 3 machines to find out how to get it right (like I did) then expect to kill your servo card at least twice
[23:05:11] <robin_sz> oh shit yes
[23:05:26] <Jacky^> ouch ..
[23:06:01] <robin_sz> so ... feel free "not to like steppers" .. but having built and sold more than 20 tables ... that would be my choice
[23:06:40] <Jacky^> good to know ..
[23:07:22] <Jacky^> steppers could be better for the interference ?
[23:08:03] <robin_sz> Jacky^: yeah, because the drivers can be near the PC in a shielded cabinet, no need to take sensitve encoders up to the table
[23:08:17] <robin_sz> of course, with the right shielding it is no problem
[23:08:34] <robin_sz> but .. expect to kill a couple of encoders or cards getting the problems sorted
[23:08:45] <Jacky^> mmhh ..
[23:09:42] <Jacky^> robin_sz: thanks :)
[23:11:08] <Jacky^> for my case, instead, should be ok
[23:11:37] <Jacky^> at least.. if i will get high speed
[23:13:55] <anonimasu> Jacky^: have you looked at servo prices?
[23:14:02] <anonimasu> Jacky^: how fast do you want to go?
[23:14:21] <Jacky^> anonimasu: how much is possible ..
[23:14:36] <Jacky^> woodworking required high speed
[23:14:47] <Jacky^> this is my issue :(
[23:15:04] <anonimasu> the limit is how much $ you are willing to throw at the problem..
[23:15:08] <Jacky^> and i want a machine dont lost steps ..
[23:15:30] <anonimasu> you shouldnt be losing steps unless your steppers are too small..
[23:15:31] <robin_sz> well, my router managed 600ipm
[23:15:35] <Jacky^> i assumed no limit to start
[23:15:39] <Jacky^> as $$
[23:15:44] <robin_sz> no limits?
[23:15:48] <robin_sz> wow ...
[23:15:48] <Jacky^> of course..
[23:15:57] <Jacky^> my budget is not infinite
[23:16:01] <robin_sz> ??
[23:16:02] <Jacky^> i'm an obbist
[23:16:06] <Jacky^> so ..
[23:16:21] <Jacky^> i can afford 1-2 k euro
[23:16:30] <Jacky^> for electronic only ..
[23:16:33] <Jacky^> not more
[23:16:35] <robin_sz> so, forget it then. if you cannot afford 10 eur for 4 micro witches, you will not affrod the machine
[23:17:07] <Jacky^> i can only say, i can choose
[23:17:22] <Jacky^> betwwen gecko G340, encoders etc ..
[23:17:31] <Jacky^> or a good steppers system
[23:17:36] <robin_sz> uh huh ..
[23:17:41] <Jacky^> 3 axis machine
[23:17:50] <anonimasu> the issue also comes down to what servos you have..
[23:18:08] <Jacky^> i dont have any servos at the moment
[23:18:13] <anonimasu> nema23 servos are a bit more then 400eur each..
[23:18:20] <robin_sz> for a router, wither is a good choice I guess .. but at 1m x 1m steppers might out perform servos for same price
[23:18:24] <anonimasu> you can use dc motors with encoders..
[23:18:26] <Jacky^> my cousin sayd he can found a lot in north italy at low cost
[23:18:41] <Jacky^> but the motors will be adeguate to the drivers..
[23:18:48] <robin_sz> servos are nice. VERY nice ..
[23:18:55] <robin_sz> but expensive ...
[23:19:09] <Jacky^> robin_sz: what you mean as servos ?
[23:19:12] <Jacky^> sorry ..
[23:19:20] <Jacky^> i mean DC motor with encoders
[23:19:23] <Jacky^> right ?
[23:19:38] <robin_sz> well, depends on what motor
[23:19:38] <Jacky^> not brushless
[23:19:39] <anonimasu> servos are dc motors with encoders that has low inertia rotors..
[23:19:47] <Jacky^> yeah..
[23:19:48] <anonimasu> or well motors.. that's optimized..
[23:19:53] <robin_sz> and bi-directional brushes
[23:20:35] <robin_sz> or better still, AC servos :)
[23:21:13] <Jacky^> but the G340 can drive it ?
[23:21:23] <Jacky^> i think not .. just DC right ?
[23:21:38] <anonimasu> dont worry about AC motors..
[23:21:41] <anonimasu> or well
[23:21:53] <robin_sz> AC is not in your budget
[23:21:54] <anonimasu> one drive retails at 1/3 of the budget..
[23:21:59] <anonimasu> the cheap ones.
[23:22:17] <anonimasu> maybe more..
[23:22:18] <Jacky^> oh ..
[23:22:23] <robin_sz> 1500 an axis for drive and motor (ac)
[23:22:25] <Jacky^> no ..
[23:22:29] <robin_sz> minimum
[23:22:56] <robin_sz> but ... whatever you use, use limit switches. cheap microswitch is fine
[23:22:57] <Jacky^> this make non sense for my need ..
[23:23:12] <robin_sz> 2 eur each
[23:23:27] <Jacky^> what ?
[23:23:35] <Jacky^> the switches ?
[23:23:38] <robin_sz> yep
[23:24:24] <robin_sz> being able to reference the machine is important
[23:24:42] <Jacky^> for me its quite clean
[23:25:15] <Jacky^> i want to start a job and finish it without lost steps, and at high speed
[23:25:25] <Jacky^> but i work only on wood
[23:25:35] <Jacky^> for my cousin is very different..
[23:25:56] <Jacky^> i will say him about what we talked
[23:26:08] <anonimasu> your cousin needs less speed..
[23:26:11] <anonimasu> most likely
[23:26:21] <anonimasu> and also less resolution
[23:26:22] <robin_sz> and a small 1mx1m machine is steppers really
[23:26:52] <robin_sz> gear for 1 turn of motor = 10mm movement and it is correct
[23:27:12] <Jacky^> robin_sz: for the plasma cutter ?
[23:27:12] <robin_sz> use about 3 to 5 Nm steppers
[23:27:14] <robin_sz> yeah
[23:27:17] <Jacky^> ok
[23:27:29] <robin_sz> for router use 5mm per turn
[23:28:14] <Jacky^> he already has some leadscrew ..
[23:28:24] <Jacky^> but i cant remember which diameter
[23:28:29] <robin_sz> leadscrew?
[23:28:31] <robin_sz> for plasma?
[23:28:41] <Jacky^> in the old machine
[23:28:52] <Jacky^> its not ok leadscrew ?
[23:28:56] <robin_sz> you cannot use leadscrew with plasma
[23:28:56] <Jacky^> for plasma ?
[23:29:01] <Jacky^> oh ..
[23:29:04] <Jacky^> why ?
[23:29:15] <robin_sz> you seen the dust it produces?
[23:29:33] <robin_sz> very VERY abbrasive dust?
[23:29:38] <Jacky^> never seen in action ..
[23:29:42] <robin_sz> it gets EVERYWHERE
[23:29:44] <robin_sz> either?
[23:29:47] <robin_sz> best option
[23:29:51] <robin_sz> toothed belt
[23:29:57] <robin_sz> second option
[23:30:03] <robin_sz> cheap rack
[23:30:09] <robin_sz> mount with rack facing down
[23:30:32] <anonimasu> robin_sz: you can do preload with a cheap rack, isnt that right?
[23:30:41] <robin_sz> mmm
[23:31:07] <robin_sz> this is plasma ... its going to be smelly and nasty .. and covered in crap anyway
[23:31:26] <robin_sz> plasma wanders about anyway
[23:31:27] <Jacky^> * Jacky^ googling for some samples of toothed belt
[23:31:46] <robin_sz> look for AT series ..
[23:32:06] <robin_sz> either AT5 or AT5L if you can fford a bit more
[23:32:22] <robin_sz> suggest 25mm or 35mm wide
[23:32:44] <Jacky^> looking ..
[23:33:05] <robin_sz> 2mm wil be fine on 1mx1m machine
[23:33:13] <robin_sz> 25mm
[23:33:21] <Jacky^> uhm
[23:33:24] <Jacky^> seen
[23:33:34] <robin_sz> big machine use 50mm, AT10
[23:33:43] <Jacky^> but ive not understood as they are mounted on a machine :(
[23:33:51] <Jacky^> i'm seraching for some picture
[23:34:02] <robin_sz> if you are very cheap use the T5 series belts, but there is backlash of about 0.5mm
[23:35:19] <Jacky^> yeah, it couldnt a prob ..