#linuxcnc Logs

Oct 27 2022

12:25 AM jpa-: solarwind: it depends on the maximum speed of the machine
12:45 AM -!- #linuxcnc mode set to +v by ChanServ
12:46 AM -!- #linuxcnc mode set to +v by ChanServ
01:07 AM Deejay: moin
01:17 AM pere: hi
01:33 AM -!- #linuxcnc mode set to +v by ChanServ
04:21 AM Tom_L: morning
04:47 AM -!- #linuxcnc mode set to +v by ChanServ
04:51 AM JT-Cave: morning
06:39 AM travis_farmer[m]: G'Morning
06:50 AM Tom_L: JT-Cave, looks like that guy got mesact going
06:52 AM JT-Cave: yeah, and now he wants personal support lol
06:52 AM Tom_L: of course
06:52 AM Tom_L: send him here, maybe somebody will help him a bit
07:22 AM c101horse8332[m]: afternoon all, since my Y axis is dead in the water due to me frying the joint 1 stepper pins on the mesa, i'd like to use one of the other 2 unused joints. where do i look and alter things to make joint 3 my new Y axis
07:23 AM ZincBoy[CAON][m]: In your HAL file. You need to specify a different stepgen for that joint.
07:25 AM ZincBoy[CAON][m]: You will have something like <card name>.0.01.dirsetup and so on. You would need to change that to <card name>.0.03.dirsetup.
07:25 AM ZincBoy[CAON][m]: All stepgen pins need to be changed to the stepgen you want to use.
07:26 AM ZincBoy[CAON][m]: That will move the Y axis joint to the channel 3 physical mesa pins.
07:26 AM c101horse8332[m]: i'd figured it be that simple, but do i keep that joint 1 or do i need to change it to say joint 3?
07:27 AM ZincBoy[CAON][m]: No. Keep it as joint 1. You are just moving the physical pins. The virtual joint stays the same.
07:27 AM c101horse8332[m]: ah ok, thats where i went wrong then i guess
07:34 AM c101horse8332[m]: i've done that now, when starting lcnc i get the following error
07:34 AM c101horse8332[m]: `./frees.hal :70: Pin pid.3.enable does not exist`
07:35 AM ZincBoy[CAON][m]: You only have to change the stepgen.01.<pin> to stepgen.03.<pin>. Don't change anything else like the pid number.
07:36 AM c101horse8332[m]: aye
07:36 AM c101horse8332[m]: thank you
07:42 AM c101horse8332[m]: no more errors starting up, now i just get a joint 1 following error as soon as i touch the Y axis buttons
07:55 AM jpa-: feedback path might need change also
08:00 AM c101horse8332[m]: where would i find the feedback path? same HAL file?
08:18 AM ZincBoy[CAON][m]: Yes.
08:19 AM ZincBoy[CAON][m]: Search for "stepgen.01" and replace it with "stepgen.03"
08:21 AM c101horse8332[m]: i've gotten rid of the following errors, still no pulsing on the Y axis
08:22 AM c101horse8332[m]: both other axis work
08:38 AM * Loetmichel just had fun with our CAD. Put 2684 hexagonal 4mm cooling holes in an 1,5mm alu PC front door. Hit "save"... *Hourglass* Make a coffee, drink it. *still hourglass* go for a smoke. *STILL hourglass* have a nice chat with the co-worker... "Ah, finally done." :)
08:42 AM solarwind: jpa- ah yeah that makes sense. Well more like maximum speed of the servo
08:43 AM solarwind: 2048 steps seems like too little for 3,000 RPM
08:44 AM solarwind: On the other hand, the leadshine drives datasheet shows analog velocity bandwidth of 500Hz which is concerning
09:01 AM skunkworks[m]: 500hz.. interesting?
09:01 AM solarwind: skunkworks[m] that's pretty low isn't it?
09:02 AM skunkworks[m]: I mean - most of the time the servo loop in linuxcnc is 1khz.. So probably usable..
09:02 AM solarwind: this is velocity control
09:04 AM skunkworks[m]: I really should buy some of these drives and see how well they actually track postion..
09:04 AM skunkworks[m]: I think people would be suprised..
09:04 AM solarwind: I'm not
09:04 AM solarwind: they work perfectly
09:05 AM solarwind: In position mode that is
09:05 AM skunkworks[m]: perfectly? how are you quantifying that?
09:05 AM solarwind: encoder readback
09:06 AM skunkworks[m]: To linuxcnc? How are you controlling the system?
09:06 AM solarwind: To a custom controller on a test bench
09:06 AM skunkworks[m]: oh - nice.
09:06 AM solarwind: an STM32H7 at 400MHz
09:06 AM solarwind: one core sesnding commands, the second core monitoring, very hard real time
09:06 AM skunkworks[m]: So - not just sending it step and direction and hoping for the best? 😉
09:07 AM solarwind: Well yeah that's the model I have, so that's the only thing I can test
09:07 AM solarwind: which is why I'm asking about the analog model which velocity/torque input
09:07 AM solarwind: The model I have is the one from stepperonline (which is the EL6 drive)
09:08 AM solarwind: practically, the difference between high speed pulse and velocity control is very little
09:08 AM solarwind: its pulse input rating is 500kHz which is a lot. At that speed, it practically becomes pulse frequency modulated velocity control
09:08 AM skunkworks[m]: Unless you are doing some crazy high acceleration you probably don't need the bandwidth. But peter would be a better person to ask
09:12 AM pcw-home: Yeah, what is your mechanical bandwidth? 30 to 100 Hz are typical for machinetools/robots
09:14 AM pcw-home: for torque control 8 bits is likely enough (its hard to get better than about 1% torque accuracy from current measurement)
09:14 AM solarwind: pcw-home thanks, any thoughts on the ADC resolution? the DMM servo drive has a 12 bit ADC
09:14 AM solarwind: ah ok
09:14 AM solarwind: how about for velocity?
09:15 AM pcw-home: well say if you have 10 bits (and 3000 RPM full speed) ad a 0.2" ballscrew
09:17 AM pcw-home: that's 0.025 RPS or 0.005" per second setting error (thats only 0.000005" setting uncertainty at 1 KHz)
09:18 AM pcw-home: so not real important (especially if you raise the sample rate)
09:18 AM solarwind: Yeah I'm trying to get information out of them about the sample rate
09:18 AM solarwind: It doesn't actually say what the drive's ADC sample rate is
09:19 AM pcw-home: other things like asynchronicity of the PWM introduce more errors
09:21 AM pcw-home: but these mostly are all swamped by mechanical errors (which become more obvious if you add linear scales)
09:48 AM skunkworks[m]: I am using pwm out of a printer port and getting pretty decent following errors..
09:49 AM skunkworks[m]: pdm
10:01 AM pcw-home: The main following error issue with linuxCNC on common machines is caused by the lack of jerk limiting
10:03 AM pcw-home: (because motors/drives have limited jerk capability)
10:15 AM skunkworks[m]: sure
10:18 AM skunkworks[m]: https://www.youtube.com/watch?v=K1yNw-DbM_0
10:44 AM Rab: skunkworks[m], cool video, but it's kind of intense that the corner of the bed is propped up on the rear face of the chuck. I guess it's not very heavy?
10:48 AM skunkworks[m]: No - it is a pretty light machine.
12:35 PM -!- #linuxcnc mode set to +v by ChanServ
02:25 PM CaptHindsight[m]: https://www.gofundme.com/f/remora-firmware-development?utm_source=customer&utm_medium=copy_link&utm_campaign=p_cf+share-flow-1
03:14 PM Rab: CaptHindsight[m], independant of the NVEM package, doesn't this lay the groundwork for LinuxCNC peripherals on generic STM32 hardware?
03:15 PM Rab: E.g.
03:15 PM Rab: NUCLEO-F207ZG
03:15 PM CaptHindsight[m]: yes, it already has
03:15 PM CaptHindsight[m]: they already have a few stm32's working
03:16 PM CaptHindsight[m]: it's a long thread
03:16 PM CaptHindsight[m]: but there is a list of them already ported
03:16 PM Rab: CaptHindsight[m], is there a good place to read discussion about this? Is it on the LinuxCNC forum/mailing list?
03:17 PM * Rab obviously hasn't been paying attention
03:17 PM CaptHindsight[m]: https://forum.linuxcnc.org/18-computer/44828-remora-ethernet-nvem-cnc-board and more ..
03:17 PM Rab: Haha, 55 pages. Cool, thanks!
03:17 PM CaptHindsight[m]: https://forum.linuxcnc.org/18-computer/42276-remora-rpi-software-stepping-using-external-microcontroller-via-spi
03:18 PM CaptHindsight[m]: I've been blabbing about it for months
03:19 PM CaptHindsight[m]: the project started a few years ago, but it really started working about a year ago
03:23 PM Rab: I thought it was all in the context of the RPi, which doesn't really interest me. I guess the earlier SPI effort is RPi-specific. But if any ethernet-enabled computer can drive any STM32 peripheral which can support the firmware, that seems like a bigger deal.
03:29 PM Rab: Like an ethernet-enabled version of STMBL which generates its own realtime signals.
03:40 PM CaptHindsight[m]: Rab: yes, he never updated the wiki after only supporting the LPC17xx
03:41 PM CaptHindsight[m]: and now there are Ethernet stm32's that work with it IIRC
03:42 PM CaptHindsight[m]: the problem now is that some of the stm32 boards that worked are not available due to the stm32 shortages
03:43 PM CaptHindsight[m]: they are currently working on support for a RT1052 based board
03:44 PM CaptHindsight[m]: https://www.nxp.com/products/processors-and-microcontrollers/arm-microcontrollers/i-mx-rt-crossover-mcus/i-mx-rt1050-crossover-mcu-with-arm-cortex-m7-core:i.MX-RT1050
03:44 PM CaptHindsight[m]: the danger is IF the vendor decides to lock the firmware the boards won't be able to be reflashed with Remora
03:45 PM CaptHindsight[m]: the microcontroller has fuses tht can be blown to lock the device to given firmware
03:51 PM Rab: Hah, CC fraud prevention doesn't like me donating to Australia.
04:23 PM CaptHindsight[m]: did it block you or just complain?
04:26 PM Rab: GoFundMe told me to check payment details or contact customer support. Then my bank called and listed a bunch of declined transactions. I added a travel authorization to my card for Australia, maybe it'll work tomorrow. ;)
04:28 PM JT-Shop: I think paypal help is all from india
04:31 PM roycroft: i get the indian call center about half the time i call paypal
04:31 PM roycroft: and i get a domestic call center the other half
04:31 PM CaptHindsight[m]: I used to get people from Ireland on PP support lines
04:31 PM CaptHindsight[m]: it might be when you call
04:31 PM roycroft: i haven't called all that many times, so i'm not sure mine is a typical experience
04:32 PM CaptHindsight[m]: outside our business hours PP is rarely anyone that sound like a native English speaker
04:33 PM CaptHindsight[m]: my banks redneck branch used to freak out when I'd tell them to add overseas transactions to my cards
04:34 PM Tom_L: i had to clear one once but from then on they allowed them
04:34 PM CaptHindsight[m]: I don't think the bank manager knew the difference between Japan, Taiwan, HK, Korea and China
04:35 PM CaptHindsight[m]: she probably would have understood if I had said "any transactions where peoples eyes are slanted"
04:37 PM roycroft: i don't mind fraud blocks on my cards
04:37 PM roycroft: it doesn't happen often, and i actually apprciate that the cc issuer is being diligent
04:37 PM roycroft: as long as it's easly to clear the blocks when i call, that is
04:37 PM CaptHindsight[m]: suck to be 12 hours off the banks time and need to use a card while traveling
04:38 PM CaptHindsight[m]: airport limo at 3am my banks time while in Tokyo
04:38 PM roycroft: i don't travel far enough away to trigger fraud blocks any more, but when i did, i would just notify the cc issuers with my travel plans ahead of time
04:38 PM CaptHindsight[m]: nobody to call
04:39 PM CaptHindsight[m]: bank fraud people can get pretty silly at times
04:40 PM CaptHindsight[m]: we once called about a login issue and one person was on the phone with them as I looked up the info, when they heard me pass the info to the person on the phone they said that they didn't allow that
04:40 PM JT-Shop: trying to setup a personal paypal account to keep from getting my debit card from being hacked
04:40 PM CaptHindsight[m]: so i had to mute the phone, talk quieter or pass only written instructions to the caller
04:41 PM Tom_L: trainee had only been there a day...
04:42 PM Thorhian[m]: CaptHindsight That reminds me of the people who think everyone in Alaska travels by dog sled and lives in igloos, or especially those who think Alaska is smaller than Hawaii because of how it is printed in maps sometimes.
04:42 PM CaptHindsight[m]: the bank also required windows and chrome browser for login
04:42 PM CaptHindsight[m]: yeah good luck with that
04:42 PM JT-Shop: I'm from Alaska and we did travel by dog sled
04:43 PM CaptHindsight[m]: JT-Shop: did you have a 1 or 2 story igloo?
04:43 PM JT-Shop: igloo's have only one story
04:43 PM JT-Shop: and it's told over and over
04:43 PM CaptHindsight[m]: sounds like the poor side of the snowbank :)
04:44 PM JT-Shop: well when your from the other side of the dog track...
04:46 PM Thorhian[m]: JT-Shop it isn’t the main form of transportation there though like some people think. I remember talking to someone in Delta Junction who called an online seller asking why they wouldn’t ship to Alaska since they were using USPS for shipping. That seller learned that priority mail works out there too lol.
04:48 PM JT-Shop: not any more but in the old days it was
04:48 PM JT-Shop: now it's just like any northern city minus the crud
04:49 PM JT-Shop: a lot of Alaskans live in the country where no roads are
04:49 PM JT-Shop: priority mail works fine for all 50 states and PR as well as any FPO address
08:20 PM Centurion_Dan1 is now known as Centurion_Dan
11:51 PM solarwind: Modern closed loop steppers are so great
11:51 PM solarwind: Nothing like an open loop stepper which misses steps so easily
11:51 PM solarwind: I'm never running steppers open loop again
11:52 PM solarwind: The DSP closed loop drivers are insanely smooth