#emc | Logs for 2009-08-02

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[09:59:16] <ilya__> What if I program G96 D- S- and everything is OK unless the X coordinate becomes very little so as the spindle can not provide needed speed wich becomes too big? How can I use the default 1000 rpm in that close to the zero X-coordinates range by program's means?
[10:01:05] <ilya__> Yesterday, I tried to upload the file and gone out of money.
[10:02:03] <ilya__> For a lathe, there are advices for the speed of the cutting for particular cutting depth and feedrate in longitudinal direction.
[10:02:09] <ilya__> kanzure:
[11:58:07] <ilya__> ´╗┐What if I program G96 D- S- and everything is OK unless the X coordinate becomes very little so as the spindle can not provide needed speed wich becomes too big? How can I use the default 1000 rpm in that close to the zero X-coordinates range by program's means?
[12:01:45] <ilya__> ilya__ is now known as jerk
[12:15:04] <jerk> people seems to ignore me, or they all are at Hawaii
[12:15:49] <SWPadnos> your question is answered explicitly in the g-code documentation
[12:15:56] <SWPadnos> unless I don't understand it
[12:16:20] <SWPadnos> this page: http://www.linuxcnc.org/docs/2.3/html/gcode_main.html (it's 28.5kB)
[12:16:49] <SWPadnos> specifically here: http://www.linuxcnc.org/docs/2.3/html/gcode_main.html#sec:G96,-G97:-Spindle
[12:16:57] <SWPadnos> D sets the max spindle speed
[12:17:25] <jerk> SWPadnos: when the bore is close to the spindle's axis, the spindle tries to speed up to maintain tha constant speed. But what if it reaches the maximum?
[12:17:45] <SWPadnos> I think the surface speed drops
[12:18:16] <jerk> SWPadnos: drops to that maximal speed?
[12:19:03] <SWPadnos> no. the spindle remains at the speed specified by D, so the surface speed drops as the radius decreases
[12:22:48] <jerk> SWPadnos: ok, thanks
[12:23:02] <SWPadnos> sure
[12:23:42] <jerk> SWPadnos: are there any free programs to create the code for lathe from the dxf drawing of the shaft?
[12:23:55] <SWPadnos> I don't know. I haven't seen any
[12:24:21] <SWPadnos> someone said they were working on one recently, but I don't remember who
[12:25:21] <jerk> SWPadnos: so, people usually program such milling?
[12:25:39] <SWPadnos> either that or they pay for the CAM software, I guess
[12:26:07] <jerk> I plan to relax for a day, then go and try to get employed with my demo drawings and codes.
[12:28:58] <SWPadnos> good luck with it :)
[12:30:07] <jerk> OK
[12:31:47] <jerk> I saw a "-2500" rpm value at Lathe axis interface once after adding the `g96 d5000 s80 M3' line after third line of the code at lathe_pawn.ini
[12:40:59] <BigJohnT> YEA! it works :)
[12:41:40] <SWPadnos> yay!
[12:41:42] <SWPadnos> what?
[12:41:49] <BigJohnT> THC
[12:42:04] <SWPadnos> of course it works. that's why it's illegal
[12:42:14] <SWPadnos> (except in California, for medicinal purposes)
[12:42:15] <BigJohnT> been working on the remove any offset as the torch raises up
[12:42:36] <BigJohnT> kind of hung me up for a while
[12:42:42] <SWPadnos> ah. cool
[12:42:57] <BigJohnT> yes
[12:43:25] <BigJohnT> that was the last piece of the puzzle
[12:46:11] <BigJohnT> next test on the live machine
[12:46:31] <BigJohnT> but first I must put up my tower on the top of the hill
[12:46:32] <SWPadnos> great
[12:46:36] <SWPadnos> heh
[12:47:39] <BigJohnT> high speed internet is just two steps away now
[12:47:40] <jerk> What is THC?
[12:47:49] <BigJohnT> torch height control
[12:48:25] <jerk> and does it connect you directly to the provider?
[12:48:36] <BigJohnT> two different things
[12:48:49] <BigJohnT> THC is for my plasma cutting machine
[12:49:16] <BigJohnT> also stands for Tetrahydrocannabinol
[12:49:59] <BigJohnT> the tower is for the ISP to put the antenna to connect to the other tower for internet
[12:50:48] <BigJohnT> I live on a dead end dirt road off of a dirt road out in the woods
[12:50:53] <jerk> BigJohnT: and, your connection to provider is still a cable one?
[12:51:15] <BigJohnT> no it will be by line of sight radio signal
[12:51:21] <BigJohnT> no cable out here
[12:51:36] <BigJohnT> I'
[12:51:44] <BigJohnT> I'm on dial up at the moment
[12:52:34] <El_Matarife> Anyone going to make it to the North Texas CNC users group meeting today?
[12:52:53] <El_Matarife> It's pretty sweet, we have a ton of operating machines, plus some great workshops
[12:53:10] <El_Matarife> But everyone's covering Mach3 and not EMC, so it'd be sweet if someone showed up and offered a workshop
[12:53:20] <BigJohnT> kinda far for me...
[12:54:12] <El_Matarife> http://www.ntcncug.com/events.htm well just in case someone is in the Dallas / Fort Worth metroplex
[12:54:23] <BigJohnT> * BigJohnT goes off to make his jerky marinade
[12:54:34] <jerk> BigJohnT: you -> device at your tower -> device at someone's tower -> Internet
[12:56:04] <jerk> El_Matarife: can you call any free from charge programs for dxf-to-gcode for Lathe
[12:57:00] <El_Matarife> Who knows, but only one or two guys there have a 4th axis right now
[12:58:01] <BigJohnT> the main tower is the ISP's tower, I need a tower to get my antenna up high enough to "see" the ISP's antenna
[12:58:55] <jerk> BigJohnT: so, your providers offer such towers... Do they offer the facilities to connect to them this way?
[12:59:01] <cradek> we considered doing something similar around '99 - glad we didn't have to
[12:59:56] <BigJohnT> yes, because this is a remote area with no cable service
[13:00:21] <cradek> yep
[13:00:25] <jerk> BigJohnT: i would be glad to get 20 Kbps GPRS via mobile phone for 25 USD per month here
[13:00:44] <jerk> BigJohnT: our midlands of Siberia are wild
[13:00:52] <BigJohnT> the only service we have is telephone and electric power
[13:01:31] <jerk> BigJohnT: you probably have a SUV with big soft wheels :)
[13:01:45] <BigJohnT> 4 wheel drive pickup
[13:02:01] <BigJohnT> and a backhoe
[13:02:28] <jerk> backhoe?
[13:02:47] <jerk> pickup is probably huge, 6 metes long ;) ?
[13:02:49] <BigJohnT> a big yellow thing that digs in the dirt
[13:03:09] <jerk> BigJohnT: oh...
[13:04:10] <jerk> I only have a motorbike. I like to ride it after rain, on an asphalt tyres.
[13:04:57] <jerk> We plan to buy some cottage in the country soon.
[13:06:22] <BigJohnT> I have a small motorcycle too, they are fun to ride
[13:07:08] <jerk> my is big but it's made as a cross-bike.
[13:09:33] <jerk> i'm using cheap norco mountainer bicycle as a crazy instead of a motorbike since I played GTA SA and tried to be more athletic. I used to cover weird distances at a weird time due to weird reasons. It helps to relax after work behind the computer.
[13:34:34] <GammaX> BigJohnT, well well....
[14:35:19] <skunkworks> we had satellite internet from hughs for a while. I worked ok. better than dialup but too many restrictions.
[14:35:34] <skunkworks> 1mb down 56kbs up
[14:37:04] <skunkworks> hughes
[14:37:11] <skunkworks> hughes
[14:37:15] <skunkworks> oops
[14:38:49] <Jymmm> skunkworks: you poor bastard
[14:39:06] <skunkworks> heh
[14:39:12] <skunkworks> when it is all you can get...
[14:39:39] <skunkworks> I don't know how it compares to what is out there now.
[14:39:56] <skunkworks> wildblue and such
[14:40:10] <Jymmm> skunkworks: No I understand, When are DSL was down temporarily, I had to setup dialup to be shared by two ppl - that was just ugly
[14:40:40] <Jymmm> you still have sat?
[14:40:54] <skunkworks> no - dsl came around a few years later.
[14:41:00] <skunkworks> here we have cable.
[14:41:23] <skunkworks> sold the equipment on ebay. :)
[14:42:21] <skunkworks> it had a whole 1watt transmitter for the send
[14:42:35] <Jymmm> We had ADSL, then switched over to VDSL a few months ago.
[14:43:26] <skunkworks> a long time ago at work - we had one dialup connection for about 20 computers. Used a webramp sharing device. worked ok.
[14:46:32] <Jymmm> Went from 1.5mbps/512Kbps on ADSL to 18Mbps/1mbps on VDSL
[14:47:28] <skunkworks> nice
[14:47:40] <skunkworks> we get by with 5mbs at work
[15:23:14] <GammaX> SWPadnos, I think I know why my machine is drifting! Possibly the wires from the scales are wired backward!
[17:13:31] <motioncontrol> good evening.Please one question.IN classic ladder editor one rung have 6 vertical line possible editing.Is possible add other line vertical ?
[18:00:32] <BigJohnT> motioncontrol: in mine I can put 9 vertical bars
[18:03:00] <Jymmm> BigJohnT: He's talking about classic ladder, not incarceration.
[18:03:18] <BigJohnT> heh
[18:04:10] <Jymmm> BigJohnT: You going Deer hunting this season?
[18:04:54] <BigJohnT> dunno, too early to tell... but if I do then there will be some smoked deer jerky
[18:05:51] <Jymmm> Hmmm, never had deer jerky. Was just gonna beg for some venison.
[18:06:23] <BigJohnT> brb gotta go check the smoker
[18:06:42] <Jymmm> bastard!
[18:08:27] <BigJohnT> 10 minutes and I have to rotate the racks
[18:08:37] <Jymmm> of?
[18:08:51] <BigJohnT> I can't wait to get the PLC controls done
[18:09:02] <BigJohnT> beef jerky
[18:09:10] <Jymmm> PLC controlled smoker?
[18:09:20] <BigJohnT> yes, with a touch screen
[18:09:29] <Jymmm> damn geek
[18:09:49] <BigJohnT> dual thermocouples one for the heat control and one to check the IT
[18:10:09] <Jymmm> IT?
[18:10:13] <Jymmm> oh
[18:10:20] <BigJohnT> geek's don't hunt deer out of the back of a pickup
[18:10:25] <BigJohnT> internal temperature
[18:10:34] <Jymmm> Wait, how are you checking the IT of jerky?
[18:10:48] <BigJohnT> that's for larger parts :)
[18:11:05] <Jymmm> you got brisketin there dont ya!
[18:11:09] <BigJohnT> you check the jerky by bending them
[18:11:24] <BigJohnT> I had wings and corn on the cob yesterday
[18:11:42] <Jymmm> hickory?
[18:12:17] <Jymmm> smoked corn?!
[18:12:18] <BigJohnT> yesterday was, today is Jim Beam oak
[18:12:30] <BigJohnT> oh yea it is good
[18:12:51] <Jymmm> I thught oak was poisonous for smoking/bbqing
[18:13:12] <BigJohnT> http://i47.photobucket.com/albums/f163/johnplctech/Smokin/P1010063.jpg
[18:13:48] <BigJohnT> that should make your mouth water
[18:14:17] <Jymmm> If I didn't just eat, it would have.
[18:14:37] <BigJohnT> bbl off to rotate the racks
[19:08:07] <BigJohnT_> BigJohnT_ is now known as BigJohnT
[19:28:43] <SWPadnos> GammaX, scales wired backwards would cause runaway, but probably not drift
[20:23:05] <Gamma-X> SWPadnos, the creep might be to not having pid setup correctly
[20:31:48] <jimbo655> GammaX: My drift was caused by ground loop check all grounding from pc to cabinet and controller to cabinet. Larger ground wire are better.
[20:42:57] <Gamma-X> I didnt have a ground... I dont think atleast lol
[20:49:23] <Gamma-X> Does emc have built in functionality to control a vfd? persay a hitachi sj200?
[21:08:03] <tom2> tom2 is now known as tom3p
[21:11:24] <jimbo655> Gamma-X:I am using a 5I20 and a 7I33 analog card. With this I can control my TECO VFD that has a 0 to +10 volt input for speed.
[21:11:49] <Gamma-X> jimbo655, is it using the modbus?
[21:13:22] <jimbo655> No it is a 0-10 volt analog input.
[21:14:33] <Gamma-X> hmm
[21:22:06] <tom3p> jimbo655: the manual says the output is +/- 10V but according to DIR. so it would seem that hardwiring DIR could get you 0-10V proportional to 0 to max rpm.
[21:25:36] <Gamma-X> any of you have breaking resistors on your vfd
[21:32:24] <skunkworks> yes
[21:35:36] <skunkworks> needed to - otherwise the spindle would not de-accellerate fast enougth with all the gearing
[21:38:38] <Gamma-X> skunkworks, did you make one or buy one?
[21:40:28] <skunkworks> I think we found one. although I don't remember exactly
[21:40:44] <skunkworks> this was for a toshiba vfd
[21:42:47] <Gamma-X> ok
[21:43:44] <Gamma-X> will a breaking resistor rated for 400v work on 220?
[21:44:18] <skunkworks> heh - I would think it would be application specific.
[21:44:32] <skunkworks> what does the vfd manual say?
[21:45:12] <Gamma-X> that hitachi sells on made for it
[21:46:57] <jimbo655> The higher voltage just gives you more insulation. As long as the Wattage (Watts) and resistance (OHMS) are correct it should be ok
[21:47:46] <Gamma-X> theres an allen bradly breaking resistor online rated for 400v for 20 bucks.
[21:51:44] <jimbo655> The resistor that you need is based on Watts, Resistance, motor size (HP) and Volts your motor is running at. The manual for your VFD should give you the information on the sizing that you need for the resistor or multiple resistors.
[21:56:21] <Gamma-X> its a 3hp motor... and the breaking resistor is 1.5kw -2.2kw
[21:56:28] <Gamma-X> think that will work
[22:08:17] <jimbo655> Worst case being that it is rated for 400 volts, it most likly has a higher resistance, your motor will not stop as fast. Buy both......
[22:08:42] <jimbo655> Run them in paralell.
[22:09:06] <jimbo655> If you need to.
[22:10:22] <Gamma-X> hmm sounds good
[22:12:32] <jimbo655> Sell the spare again if you don't need it .....
[22:14:01] <SWPadnos> Gamma-X, regarding modbus, there are a few modbus VFD drivers out there now, it should be possible to make one of htem work with yours (if it's not already supported)
[22:14:35] <Gamma-X> SWPadnos, Its a hitachi sj200
[22:14:43] <SWPadnos> yep, I saw that
[22:15:05] <SWPadnos> I don't remember what the second driver was for. I know the first was for the Automation Direct GS2 (because I wrote that one :) )
[22:16:03] <Gamma-X> damn.. lol
[22:24:22] <jimbo655> SWPadnos: I am looking at a 256 PPR encoder with index pulse for the spindle. Good bad ugly....
[22:24:58] <SWPadnos> it sure won't be a problem for the Mesa card to count
[22:25:46] <SWPadnos> the place where it could possibly be bad would be low speed threading, I think
[22:26:00] <SWPadnos> but it's probably fine for that too
[22:27:20] <jimbo655> Thanks... I will pick it up.....
[22:27:40] <SWPadnos> uh. don't listen to me on that, I have no practical experience :)
[22:28:07] <jimbo655> OK no big deal....
[22:29:56] <Gamma-X> jimbo655, my vfd has analog input! yay! Was it hard to command the speed you want? Im thinking I want to put a encoder on my spindle to see the speed. and possibly have emc adjust the vfd accordingly.
[22:30:44] <jimbo655> Gamma-X: http://wiki.linuxcnc.org/cgi-bin/emcinfo.pl?Analog_Spindle_Speed_Control
[22:31:01] <Gamma-X> sweet! thanks
[22:31:10] <Gamma-X> Thats much appreciated.
[22:31:46] <SWPadnos> note that analog control can be better than modbus, since the modbus components run in userspace and the update rate is somewhat slow
[22:32:04] <SWPadnos> spindles don't usually react too quickly anyway, but it could be a problem if you want to do spindle speed PID
[22:32:57] <Gamma-X> SWPadnos, can u please give a jist of spindle speed pid?
[22:33:17] <SWPadnos> PID is PID, it doesn't matter if it's a servo axis or an air conditioner
[22:33:21] <SWPadnos> or a spindle
[22:33:26] <Gamma-X> wow
[22:33:39] <Gamma-X> i gotta relearn pid! I want to curse realy loudly lol
[22:33:55] <SWPadnos> the theory is the same, though the coefficients will be very different depending on the application
[22:40:58] <jimbo655> before you hook up the MEsa card to your control use an OHM meter to see if you have resistance between 0v conection and the ground buss of the controller. If you have any resistance there it is possable to blow your card. This is waht MESA told e.
[22:41:01] <jimbo655> ME
[22:47:09] <Gamma-X> nice...
[22:47:30] <Gamma-X> well the hitachi is like a piece of art... japanese made and tons of features.