#linuxcnc Logs

May 13 2021

#linuxcnc Calendar

12:02 AM net|: https://raw.githubusercontent.com/netpipe/RightHand/main/ss.png
12:16 AM Connor: allow-hotplug enp1s0
12:16 AM Connor: auto enp1s0
12:16 AM Connor: iface enp1s0 inet static
12:16 AM Connor: address
12:16 AM Connor: pcw_home: is what I have.
12:16 AM XXCoder: yo
12:20 AM Connor: I have to do ifdown / ifup or restart networking if I power cycle the 7i96
12:32 AM mrec_: does anyone know is there a difference between a hss-co drill and a hss tool for the lathe?
12:32 AM mrec_: (difference in material)
12:32 AM mrec_: I tried to part off with a hss-co drill (since that's what I have here at the moment) and the tool is damaged quickly
12:32 AM mrec_: I ground the hss-co drill (shaft)
12:32 AM XXCoder: mystery alloy vs actual carbide?
12:32 AM mrec_: I'm just testing, I'm fine with carbide
12:36 AM mrec_: the drill says hss-co TPT il85
01:27 AM Deejay: moin
01:53 AM mrec_: so 2 more hours trying to part off with my mini lathe there's only one way to do that successful (and it works with carbide), whatever I try just running the tool into it will not work
01:53 AM mrec_: that was just some experimenting time with different parameters
01:55 AM mrec_: does anyone have experience with a 4jaw vs 3jaw chuck?
01:55 AM mrec_: is a 4jaw chuck supposed to be more rigid?
01:57 AM sensille: mrec_: for parting off on my mini lathe i need to tighten down the cross slide and sharpen the tool
02:00 AM mrec_: I use to go into it run the Z axis 0.8mm forward and backward and go deeper, same game again
02:01 AM rs[m]: mrec_: with HSS you have to be careful so it doesn't get hot
02:01 AM mrec_: that works successful and repeatable
02:02 AM mrec_: anything else doesn't seem to work properly with that lathe
02:02 AM mrec_: so in total 2.8mm material will be wasted (I'm parting 32mm steel)
02:03 AM mrec_: the only other problem I have is clamping the material, I need to support it with the tailstock otherwise it moves so seems like the chuck has some issues.
02:03 AM mrec_: it moves in Z direction
02:05 AM mrec_: parting 20mm steel is no problem at all, but going from diameter 32-~20mm is
02:31 AM mrec_: tried 1.5mm, 2mm and 2.5mm parting tools all unsuccessful the regular way with an unmodified mini lathe
02:31 AM mrec_: the 0.8mm z slide is okay
02:32 AM mrec_: I can part off 5cm without support (but the z axis holding of the part in the chuck is weak) possibly some vibrations kick the material out
02:34 AM mrec_: that's why I ask if anyone has experience with a 4 jaw chuck :-)
04:12 AM mrec_: big power outage in Taiwan
04:13 AM mrec_: anyway I took the time to install a 4jaw chuck which was installed in another tool magically it matched the 3jaw chuck plate
04:13 AM mrec_: time for testing
04:26 AM Tom_L: morning
05:42 AM JT-Cave: morning
06:00 AM mrec_: 4 jaw chuck improves the situation on the minilathe so nice we have electricity for 30 min and then 30-60 min off again
06:45 AM * JT-Cave only uses 4 jaw chucks on the lathes when I use a chuck
06:47 AM XXCoder: how many 4jaws can chuck check when he chucks chucks
06:47 AM mrec_: I'm using the 3jaw now for gear cutting that should be okay I hope
07:15 AM mrec_: ok I'm parting at 2000rpm now
07:15 AM mrec_: any experience with parting at that speed with a mini lathe?
07:17 AM mrec_: ok first result is good and it's sparking a bit
07:17 AM JT-Cave: if everything is very rigid you might not break the cutter... if not
07:17 AM mrec_: a little bit chattering but that might be due to manual operation via linuxcnc
07:18 AM mrec_: the parted surface is nothing like it was with 300rpm it's much better and no workaround needed (like sliding Z 0.8mm)
08:07 AM mrec_: parting at high speed just has an effect on the chattering. The frequency is high enough to get through it but it's not healthy for a small lathe
08:07 AM mrec_: I'll stick with low RPM + 4jaw (which fixed the material shifting in Z direction)
09:33 AM veegee: roycroft http://store.mesanet.com/index.php?route=product/product&path=69_73&product_id=217
09:33 AM veegee: I think I've settled on that one. What do you think?
09:34 AM veegee: The picture looks wrong though
09:34 AM veegee: I don't think the 6i25 looks like that. The PCIe connector should be much shorter
09:44 AM Rab: veegee, I think the picture might show a 5i25. This is the 6i25: http://store.mesanet.com/index.php?route=product/product&product_id=58&search=6i25
09:44 AM veegee: Ah yeah that looks right
09:44 AM veegee: I should be able to do anything with this setup
09:45 AM veegee: I can fully offload motion control (step generation) to the 6i25 and hook up my stepper motor drivers to the 7i76 right?
09:46 AM roycroft: yes, that picture is a 5i25 - that's the bundle that i have
09:47 AM roycroft: and yes, it will work exactly as you just said
09:53 AM veegee: perfect, thanks <3
09:54 AM roycroft: you may need to install firmware on the 6i25
09:54 AM roycroft: on the 5i25 there are different firmware images, depending on the motion controller you're using
09:55 AM roycroft: but all that stuff is well documented
09:55 AM veegee: Yeah they claim the g code interpreter firmware is included with the purchase of an FPGA card
09:56 AM roycroft: you might want to order the din rail mounting bracket for the 7i76
09:58 AM roycroft: http://store.mesanet.com/index.php?route=product/product&path=74_79&product_id=227
09:58 AM roycroft: i think that's the one
10:01 AM veegee: Got it, thanks
10:03 AM veegee: How is it multiplexing all that I/O over a 25 pin connector?
10:03 AM veegee: obviously it's not a 1:1 pin mapping, so there must be some protocol between the 6i25 FPGA and 7i76 daughter card
10:42 AM Rab: veegee, from p.10 of the 7i76 manual, looks like most pins are mapped directly to conventional step/dir functions, while a few pins are used for the proprietary Smart-Serial interface.
10:43 AM rs[m]: veegee: slow signals are accessed via smart serial protocol
10:44 AM Rab: So I would guess that if you only had a 6i25, you could use it with a conventional parport BoB. But the 7i76 can multiplex additional signals through smart serial.
10:45 AM Rab: And as the manual notes, the exact pin configuration will depend on your chosen 6i25 firmware; that's just a typical config.
11:11 AM veegee: rs[m] Rab thanks guys. The 6i24-25 looks like it gives more capability then
11:11 AM veegee: 3x 50 pin headers
11:24 AM roycroft: iirc, my plan was to connect the pendant controller to the rs-422 interface on the 7i76
11:25 AM roycroft: i really need to get back to that project - it's ridiculous how long it's taken me
11:28 AM veegee: I'm thinking of doing the 6i24-25 + 7i76 combo instead of the 6i25
11:29 AM veegee: I feel like the 6i24-25 has waaayyyyy more high speed I/O directly connected to the FPGA
11:34 AM mrec_: does this device register another PCI bus where the FPGA is connected?
11:40 AM mrec_: I guess they only developed the PCI-FPGA and are using a bridge and some tranceivers
11:40 AM roycroft: you might want to check with pcw or jt before ordering, veegee
11:40 AM veegee: roycroft they're the guys behind Mesa?
11:40 AM roycroft: pcw is mesa
11:40 AM roycroft: jt is a mesa reseller
11:40 AM veegee: roycroft will do, thank you
11:40 AM roycroft: either of them should be able to answer any of your questions and provide you with a sanity check
11:40 AM veegee: indeed
11:40 AM andypugh: Connor: Catching up… X=0 should be with the slide all the way out, X = -7 with it all the way in (away from the operator)
11:41 AM veegee: Honestly though at these prices, getting the wrong card isn't a mistake because I have plenty of uses for PCIe FPGA cards in general and multiple machines which I plan to automate
11:41 AM pcw_home: 7I52S maybe
11:42 AM veegee: pcw_home I mean... insanely expensive, don't raise the prices!!!!
11:42 AM andypugh: 7i47 for steppers
11:42 AM pcw_home: In general the DB25 cards have better support for slow I/O for limit switches etc
11:44 AM veegee: My first immediate project is to replace the shitty broken motion control card with an FPGA system like the 6i25+7i76 combo, add limit switches, add an MPG, etc.
11:44 AM andypugh: My lathe is 6i24 + 7i49 + 7i44. Then the 7i44 connects a 7i84, 7i73 and 2 x 8i20. Which actually leaves me with a spare 50pin port.
11:44 AM veegee: if it can do all that, I'll blindly buy that to start with
11:45 AM andypugh: You could look at the 7i76E too. All in one, ethernet connected.
11:45 AM veegee: I want to avoid any serial type interface unless it's for controlling my VFD for example
11:45 AM veegee: want to avoid ethernet, it's not the right protocol for real-time motion control
11:45 AM veegee: fine for sending G code though
11:46 AM andypugh: Ah, well, you don’t want a 7i76 then, the GPIO on that is serially interfaced :-)
11:46 AM veegee: yeah that was my only concern
11:47 AM veegee: ALTHOUGH, serial as in high speed SPI is fine if there are real time guarantees on how the GPIO is demuxed
11:47 AM veegee: otherwise, directly connected to the FPGA's pins is the best way to get perfect cycle-by-cycle timing
11:48 AM pcw_home: If you do not need control faster than the servo thread rate Ethernet and Serial are fine (that is they are real time at the servo thread rate)
11:48 AM veegee: pcw_home "servo thread rate", as in pulse frequency?
11:49 AM veegee: if so, yes that should be fine
11:49 AM pcw_home: No, LinuxCNCs typically 1KHz servo thread rate
11:49 AM veegee: oh the kernel tick frequency?
11:50 AM veegee: But I do intend to offload motion control to the FPGA
11:50 AM pcw_home: Why?
11:50 AM veegee: I don't want my computer or linuxcnc doing any kind of step/pulse generation
11:50 AM pcw_home: It does not, the FPGA generates the step pulses
11:50 AM andypugh: Step generation is not motion control.
11:51 AM veegee: so LinuxCNC sends the G code?
11:51 AM pcw_home: No, linuxcnc sends step rates
11:51 AM veegee: ok like a master clock?
11:52 AM pcw_home: (1000 times a second)
11:52 AM mrec_: the fpga will be for velocity pid
11:52 AM mrec_: afaik :-)
11:52 AM andypugh: “For the next millisecond pulse the X stepper at 1.2567Hz”
11:52 AM veegee: andypugh thanks that explains it perfectly
11:53 AM pcw_home: the FPGA stepgen hardware is just a digitally controlled oscillator (but with count feedback)
11:53 AM pcw_home: well fractional count feedback...
11:53 AM veegee: so nonetheless LinuxCNC _is_ doing motion control
11:53 AM veegee: I'd still highly prefer the FPGA to do that part
11:54 AM andypugh: The FPGA doesn’t know enough to do motion control.
11:54 AM veegee: isn't there a G code interpreter firmware for the FPGA?
11:54 AM pcw_home: Thats what system like Mach do (buffered motion)
11:54 AM veegee: yeah mach is something I want to stay far away from
11:54 AM andypugh: Unless you want to put a G-code interpreter in the FPGA. At which point you have a Smoothstepper, and the limitations thereof.
11:55 AM veegee: Yeah I thought Mesa had firmware for that
11:55 AM andypugh: LinuxCNC is a lInux based motion controller. Anything else is something else.
11:55 AM pcw_home: LinuxCNC has a different model (trajectory planning and complex motion in the host)
11:55 AM andypugh: There is Mesa SoftDMC.
11:55 AM andypugh: But you can’t use SoftDMC with LinuxCNC.
11:56 AM veegee: ok that helps a lot, thanks
11:56 AM veegee: I'm assuming the FPGA buffers the step rates to synchronize all axis?
11:56 AM andypugh: No. No buffering, which is why we need a realtime system on the host.
11:57 AM veegee: ok so one way or another, the step rates are sent one after the other for each axis
11:57 AM veegee: unless there's some sort of a "memory barrier" or sync signal to tell it to "Go!" after it receives step rates for all axis, they will be slightly out of sync, no?
11:59 AM andypugh: Each stepgen register is updated within a matter of nanoseconds. Basically as fast as data can fly through the PCI bus.
12:00 PM veegee: ah ok
12:00 PM veegee: I need to do some deep diving into the architecture
12:01 PM veegee: So LinuxCNC does the trajectory planning, sends low level instructions to the FPGA, which then does the step/dir pulses
12:01 PM pcw_home: Yes there can be a few usec differences in the velocity update times ( which is not significant as a source of errors at normal acceleration rates )
12:01 PM veegee: Yeah that was my main concern, hence the desire to do the motion control in hard real-time
12:02 PM andypugh: Just how fast can your hardware react? What are you controlling?
12:02 PM veegee: but if it's a non issue in practice, I'm not worried
12:02 PM veegee: andypugh lol! good question
12:02 PM veegee: steppers are obviously fine, but I didn't want to be limited
12:03 PM veegee: andypugh your setup of 6i24 + 7i49 + 7i44 looks like a better fit for me then
12:03 PM andypugh: If it’s a laser galvanometer these issues are worth considering. Otherwise generally not.
12:04 PM andypugh: You only want a 7i49 if you are running with Resolvers
12:04 PM pcw_home: Yeah galvanometers are 100s of Gs
12:04 PM andypugh: 6i24 + 7i47 might be a good choice
12:05 PM veegee: 7i47 communicates with the FPGAs over RS422?
12:05 PM andypugh: Interesting question…. How fast is it possible to scan a laser beam across a target with a galvanometer?
12:05 PM pcw_home: no the 7I47 is a RS-422 interface for the FPGA
12:06 PM veegee: so the step/dir is being sent over RS-422?
12:07 PM andypugh: veegee: No. Individual FPGA pins are buffered to be compatible with RS422 voltage levels.
12:07 PM pcw_home: Faster drives use RS-422 (differential step and dir)
12:08 PM veegee: Ah, forgot that RS422 can do 10mbit/s
12:08 PM andypugh: You might want the 7i47S if you want to drive a spindle, it has a digital potentiometer for controlling a VFD.
12:08 PM veegee: ok so that's plenty fast then
12:08 PM pcw_home: But it generally works with normal OPTO isolated stepper drives or you can just use one output single ended
12:08 PM veegee: "A common usage of the 7I47 would be connecting up to 6 step+direction step drives to the 7I47's RS-422 outputs" so it can also operate in step/dir mode instead of RS-422
12:09 PM pcw_home: (we use RS-422 drivers with 5V swing)
12:10 PM andypugh: RS-422 in this case refers to the physical interface, ie a differential pair of 5V outputs.
12:10 PM veegee: OH sorry I'm a bit braindead today
12:10 PM pcw_home: basically just a buffer card that supports 5V 24 mA signals either differential or single ended
12:10 PM veegee: Yeah, so it's just a differential signal driver board essentially
12:10 PM Connor: I'm still having troubles with the PC not bringing up the enterface when the mesa card is unplugged and plugged back in, or turned off/on.
12:10 PM veegee: so can be used single ended for normal step/dir
12:10 PM Connor: If I restart networking or do ifdown/ifup I can get it working.
12:11 PM veegee: Connor I'll help you in a moment after I get this sorted out and my mesa cards ordered
12:11 PM andypugh: I do think that the Mesa description of the 7i47 is confusing. It really does sound like it is a serial interface board, whereas it is really just a buffer/protection board that also does single-ended to differential.
12:11 PM veegee: andypugh 100% agree
12:11 PM veegee: if they just called it a differential output buffer board, I no be so Confucius u kno?
12:12 PM veegee: I really thought it was doing everything over RS-422
12:12 PM pcw_home: It als has RS-422 receivers (for encoder inputs) But it can be use for serial interfaces as well
12:13 PM andypugh: Connor: Step 1, uninstall wicd. Then install nm-tray. That will install network-manager. And life gets eaiser.
12:14 PM Connor: I think I may have done that. At least uninstalled or disabled the stock network manager in X
12:14 PM andypugh: (Though, depending on your desktop settings, nm-tray might not actually show up)
12:14 PM veegee: So I guess I'm going with the 6i24-25 + 7i47 to control my stepper drivers. Do I need another daughter card for limit switches and MPG etc?
12:14 PM veegee: LIke a GPIO board
12:14 PM veegee: or does the 7i47 have enough IO for that?
12:14 PM pcw_home: No you would need a card like a 7I37TA
12:15 PM andypugh: If you want to run the limit switches at more than 5V, then yes.
12:16 PM pcw_home: I honestly think you would be better of with a 6I25/7I76 or 7I76E or 7I96 for a first time LinuxCNC installation
12:16 PM mrec_: andypugh: digital potentiometer -> pwm filtered with a resistor/capacitor?
12:16 PM andypugh: Either 7i37TA (as suggested) or 7i44 + 7i84 if you think you might need a lot more IO in the future. Except that 7i44+7i84 is all serial, so against your religion :-)
12:17 PM mrec_: and possibly an opamp
12:18 PM andypugh: mrec_: No, an actual digital pot, so the output varies propotionally to the voltage suppled by the VFD, and is electrically isolated from the board logic.
12:19 PM andypugh: mrec_: An example: https://uk.rs-online.com/web/p/digital-potentiometers/8895878/
12:22 PM mrec_: andypugh: is that one used on the mesa boards?
12:22 PM mrec_: 20 %
12:22 PM mrec_: tolerance: 20 %
12:23 PM andypugh: I have no idea which one Mesa use. PCW prpobabluy knows :-)
12:23 PM mrec_: I'd be interested in the circuit or a photo of it :-)
12:24 PM mrec_: I'm using PWM and a filter to generate 0-5V
12:25 PM andypugh: I think that they are an actual resistor network and a set of switches.
12:36 PM pcw_home: We use PWM --> Fast OPTO --> 2 pole filter --> OP-Amp buffer
12:44 PM mrec_: I skipped the op-amp in my setup it's not required.
12:44 PM mrec_: (but that's only my setup of course)
12:44 PM Connor: andypugh: wicd was disabled from startup, but, I went ahead and uninstalled it. I'm using interfaces file in network
12:44 PM pcw_home: In general the OP-AMP make the output more accurate (and allows higher impedance filter components that end up using lower current)
12:47 PM drdoc: pcw_home: I had a question about the latency script on the forum
12:48 PM JT-Cave: I usually just edit /etc/network/interface and add the static ip
12:49 PM drdoc: running a hobby-class machine with a Mesa 7i96, what kind of script result is the threshold, where the PC is no longer the bottleneck?
12:49 PM * JT-Cave notices that lunch minute is up
12:49 PM JT-Cave: run latency-histogram --nobase
12:49 PM drdoc: have done
12:51 PM andypugh: I am not sure that the PC is ever the bottleneck.
12:51 PM drdoc: really?
12:52 PM andypugh: Well, first, what do you mean by “bottleneck”?
12:53 PM drdoc: I mean that the latency of the PC affects speed of operation
12:53 PM drdoc: Assuming I'm running appropriate steppers & drivers
12:58 PM pcw_home: the PC latency is not really significant as long as it can manage a 1 KHz or even 500 Hz servo thread
01:01 PM drdoc: I think I might be there
01:01 PM drdoc: servo min: -41.000 uS max: 43.500 uS sdev: 1.900 uS
01:01 PM drdoc: ;)
01:02 PM drdoc: that 40 uSec outlier drives me nuts though
01:03 PM drdoc: it's cyclic, somewhere between 60 & 90 seconds
01:05 PM pcw_home: The Ethernet ping times are important also (the latency test is very optimistic because is doesn't actually do anything, no hardware access, no memory allocation etc etc)
01:07 PM drdoc: right
01:08 PM drdoc: This is a Supermicro motherboard with a decent Intel NIC, but I haven't tested a direct connection yet
01:11 PM pcw_home: If it has an Intel NIC you will need to disable IRQ coalescing (man hm2_eth)
01:11 PM drdoc: thanks, that's good to know
01:12 PM pcw_home: The Intel driver defaults to having IRQ coalescing enabled
01:13 PM drdoc: I know, and it's almost never useful
01:13 PM Connor: remove wicd looks to have worked.. simply disabling the tray from startup hide most of the problems, but not with the ethernet..
01:13 PM Connor: I have nm-tray working simply on the wifi and have the mesa done through the interfaces.
01:14 PM drdoc: Connor: that's my only real beef with Debian, from version 7 up till now
01:14 PM drdoc: network configuration is straight-up broken OOB
01:14 PM Connor: Can we not change that in our ISO distribution?
01:14 PM pcw_home: wicd works in simple cases, anything more complex it breaks
01:14 PM Connor: remove the wicd and use something else?
01:15 PM Connor: I would use straight interfaces for this machine if I wasn't shipping it to someone. He needs to be able to find his WiFi and set it up.
01:15 PM Connor: but, I don't want him messing with the ethernet..
01:15 PM drdoc: honestly, I'm with JT-Cave - if you can't properly edit /etc/network/interfaces, you're going to have other problems too
01:16 PM drdoc: for situations like Connor's, it's easy enough to install a GUI tool
01:16 PM pcw_home: the network manager gets along with the interfaces file
01:16 PM andypugh: I have already removed wicd from the ISO sources. I just haven’t re-masteres the ISO yet.
01:17 PM drdoc: lol
01:17 PM drdoc: Problem Solved.
01:18 PM * drdoc goes back to shopping for CAM software
01:19 PM Connor: Right, it just requires x-term to be installed to run the config from the tray..
01:21 PM drdoc: Is anybody running < $500/yr CAM software they like?
01:21 PM Tom_L: is there such a thing?
01:22 PM drdoc: BobCAM, ESTL, Heeks, MeshCAM
01:22 PM drdoc: there are many
01:24 PM drdoc: I've worked with Mastercam & FlatCAM, but really nothing in between
01:24 PM drdoc: and I don't have legitimate access to mastercam anymore
01:25 PM Tom_L: my kid is learning mastercam
01:25 PM Tom_L: student copy doesn't output code
01:25 PM drdoc: right
01:26 PM Tom_L: i own smartcam which is old but competed with mastercam
01:26 PM drdoc: we used an ancient version at Brandt
01:26 PM drdoc: I remember you said, but it's out of my price range
01:26 PM Tom_L: the rest will be 2.5d not full 3d
01:27 PM drdoc: I can live with that for now
01:29 PM drdoc: there are cracked copies of MC out there, but I'd much prefer to stay legal
01:29 PM drdoc: that's more about karma than kops
01:31 PM drdoc: my old employer wanted to make me a *very* good deal on their TopSolid seat, but umnpaid support is nonexistent
01:31 PM drdoc: as is english documentation
01:42 PM roycroft: i don't know what you need to do, but freecad has a path workbench that can generate gcode, and openscad can also generate gcode
01:45 PM drdoc: openscad makes the baby Jeebus weep
01:46 PM drdoc: just sayin
01:48 PM drdoc: Hmmm. Homebrew has a freecad port
01:51 PM roycroft: if i ever make any sense of freecad, i anticipate i'll use a combination of freecad and openscad, with the the openscad workbench in freecad
01:51 PM roycroft: so my new motor just arrived
01:51 PM Connor: OKay, what remote admin software can I install on this machine that lets me remote in (with user permission) without having to deal with opening up ports and port forwards in their router? VNC would normally be my go to for this..
01:51 PM roycroft: when it left china it was protected by 2 pieces of styrofoam
01:52 PM roycroft: it now has about 40 pieces of styrofoam
01:52 PM roycroft: but it appears to be intact
01:52 PM roycroft: it also has a big sticker on it warning me that i must read the instruction manual before installing it or i might die
01:52 PM roycroft: no such document was provided, however
01:53 PM drdoc: course not
01:53 PM roycroft: i'm feeling good today, so i may decide to tempt fate by installing without reading the document
01:53 PM drdoc: I do recall seeing a PDF link on the web page though
01:53 PM roycroft: if you don't see me any more after today there's a good chance you'll be able to figure out what happened
01:53 PM drdoc: not terribly worries
01:54 PM drdoc: worried
01:54 PM roycroft: the wiring diagram is printed on the motor
01:54 PM roycroft: that should be all the instruction i need
01:54 PM drdoc: that's what I was typing
01:54 PM CaptHindsight: CDC eases indoor mask guidance for vaccinated adults
01:55 PM roycroft: i mean, i'm sure there are other things the instruction manual says, like "do not install underwater" and "do not install in a room full of gas fumes"
01:55 PM roycroft: yes, i saw that
01:55 PM drdoc: CaptHindsight: I was looking at the motor pics yesterday
01:55 PM roycroft: i'll wait for our governor to make a statement before i change my behaviors
01:56 PM roycroft: my county should be over 50% of adults fully-vaccinated now, and the county health department are focusing on teens
01:56 PM drdoc: I've resuscitated bike motors that looked that bad
01:56 PM roycroft: we're nowhere near herd immunity et
01:56 PM roycroft: but we're close to the tipping point where the case numbers will go way down
01:56 PM roycroft: 60% is the estimated tipping point for that
01:57 PM drdoc: roycroft: our Beloved Idjit cancelled the mask orders entirely months ago
01:57 PM roycroft: there's a scottish term for people like him - eejit
01:57 PM drdoc: yup
01:58 PM drdoc: I thought Rick Perry was about as bad as it could get
01:58 PM drdoc: then we got Abbott
01:58 PM roycroft: i was concerned that when the mask mandate goes away i won't be able to recognise and avoid the maga folk so easily
01:58 PM drdoc: lol
01:58 PM roycroft: but upon further reflection, i think i'll probably still be able to recognise them
01:58 PM drdoc: yup
01:58 PM roycroft: abbot is the clever version of perry
01:59 PM roycroft: note i did not say smart
01:59 PM roycroft: i said clever
01:59 PM CaptHindsight: drdoc: yeah most wipe right off, it just went from a refresh to a rebuild and bore with all new bearings , rings pistons, maybe cam and lifters
01:59 PM drdoc: I did note that
01:59 PM drdoc: and agree
01:59 PM roycroft: anyway, it is lunch time
01:59 PM roycroft: i'm going to go disassemble my belt grinder so i can bore and tap holes for the new motor
01:59 PM drdoc: CaptHindsight: yeah, but now you have an excuse to make it zoom
02:00 PM CaptHindsight: drdoc: I was hoping to get away with just a good cleaning and new gaskets and seals
02:00 PM roycroft: i should have the motor running today - then i'll just be waiting on that shaft bushing to have the machine functional again, and that bushing should arrive in a couple days
02:00 PM drdoc: right, but that almost never happens
02:00 PM CaptHindsight: drdoc: will be ~240hp going into a Fiero with 4t65 (4s-auto)
02:00 PM drdoc: roycroft: sweet. I'm anticipating your review
02:01 PM drdoc: CaptHindsight: that's nearly a HP/lb, right?
02:01 PM drdoc: :-p
02:01 PM CaptHindsight: drdoc: yp from the factory 92hp in the 4cyl Iron Duke
02:01 PM drdoc: yeah
02:02 PM CaptHindsight: it's a friends car, a barn find
02:02 PM roycroft: if it spins round and round, and the blue smoke does not escape, i'll call it a win
02:02 PM drdoc: I drove a friend's Fiero once. It seemed like a well-designed car that got gelded in the execution
02:03 PM drdoc: roycroft: if it walks off the table?
02:03 PM CaptHindsight: drdoc: it has no brakes yet so I haven't driven it :)
02:03 PM drdoc: yeah, don't
02:03 PM drdoc: :)
02:04 PM drdoc: those assholes shipped a new phone in a padded envelope
02:04 PM drdoc: Amazon
02:05 PM CaptHindsight: yeah, crappy packaging
02:06 PM drdoc: oh well
02:32 PM andypugh: drdoc: If you are looking on homebrew then presumably you are working on a Mac? How much do you hate Autodesk?
02:33 PM andypugh: Because the CAM in Fusion360 is really very good.
02:34 PM andypugh: I know that I should get in to FreeCAD, but then I want to make a part in a hurry, and have been using AutoCAD / MD / Inventor / Fusion for 30 years and go with what I know.
02:34 PM veegee: As it stands, can LinuxCNC run on rpi4 and send step/dir pulses out the GPIO?
02:35 PM veegee: I just want to run some tests on my stepper drivers with nothing other than my rpi4
02:35 PM andypugh: Yes.
02:35 PM veegee: excellent, thanks
02:35 PM andypugh: Use the normal software stepgen and the hal_pi_gpio driver.
02:42 PM veegee: thanks
02:43 PM CaptHindsight: veegee: you'll just be limited by the 70uS of latency jitter
02:44 PM CaptHindsight: so with the reset function for software stepping ~80-90uS per step
02:45 PM CaptHindsight: if you never run a browser or play a video while running LCNC you can move/step a little faster
02:46 PM CaptHindsight: IF you use an OrangePi with an H3 then you can software step to 500KHz
02:46 PM CaptHindsight: still in Beta though
02:48 PM CaptHindsight: ESP32 boards came in the other day, have to try the software stepping over UDP on those
02:48 PM CaptHindsight: https://www.youtube.com/watch?v=_Goi4YVU0js
02:49 PM roycroft: well, this is not fun any more
02:49 PM CaptHindsight: hope he implemented it well so that it doesn't lose steps
02:49 PM roycroft: because the new motor has a slightly shorter shaft than the old one, the motor mount holes do not line up, which i anticipated
02:49 PM roycroft: but the new ones overlap the old ones, which i was hoping would not be the case
02:50 PM roycroft: now i have to decide what to do
02:50 PM CaptHindsight: have pics or drawings?
02:50 PM roycroft: no, not yet
02:50 PM CaptHindsight: this the ones with the mounting holes 1/2 the hole dia off?
02:50 PM roycroft: i need to pull the drawings for the machine off my gitlab server, and then i can overlay the new holes over hte old ones
02:51 PM roycroft: this is a different machine with that problem :)
02:51 PM roycroft: it's not quite 1/2 diameter, i think
02:51 PM roycroft: i was just eyeballing it for now
02:51 PM roycroft: when i check out the cad drawing i'll nail it down
02:51 PM CaptHindsight: offset mounting studs?
02:52 PM roycroft: the mounting holes on the motor base are elongated, which gives me some movement perpendicular to the motor shaft, if needed
02:52 PM roycroft: and i'll probably need to do that
02:52 PM roycroft: but they're pretty long, so i may be able to move the mounting holes inward, towards the center of the motor, just enough to avoid the overlap, and still have some adjustment room
02:53 PM CaptHindsight: https://cdn.shopify.com/s/files/1/2445/5993/products/458001_480x480.jpg
02:54 PM roycroft: i'm not completely sure where they ned to be at this point - i could not tell exactly where the drive wheel was mounted on the old motor, so i don't know the exact distance from the center of the drive wheel to the center of the first row column of mounting holes
02:54 PM roycroft: but my cad drawing will tell me that
02:54 PM roycroft: those are clever, but they won't work
02:54 PM roycroft: i'm using screws, not bolts
02:55 PM roycroft: and they cannot protrude through the back of the mounting plate
02:56 PM roycroft: i'm not making a new mounting plate, and i really don't want to weld up the old mounting holes, because i can almost guarantee i'd break at least one tap trying to tap new holes through partial weld
02:56 PM roycroft: i think moving the holes inward a wee bit will end up being the solution
02:57 PM CaptHindsight: hand tap with no more than 180 deg before cleaning tap
02:57 PM * roycroft has done that before, and has learned a few tricks, but it's still iffy
02:57 PM CaptHindsight: 1/4" or 3/8" threads?
02:57 PM CaptHindsight: or more bigger?
02:57 PM roycroft: 3/8"
02:58 PM CaptHindsight: I have never broken a hand tap 3/8" (9.5mm) or larger
02:59 PM CaptHindsight: I probably need to try harder
02:59 PM roycroft: i hae
03:00 PM roycroft: have
03:00 PM roycroft: that's the largest size tap i've ever broken
03:01 PM roycroft: but on a more positive not, i think i have figured out the stock market
03:01 PM roycroft: when i own a stock that's taking a dive, and i think it's going to rebound, all i have to do is put in a buy order at what i think will be the low price, and it starts recovering immediately
03:01 PM roycroft: and my buy order is never filled
03:02 PM roycroft: i've done this 3-4 times in a row of late
03:27 PM * Tom_L wonders if roycroft should be playing with 3phase and the stock market on the same day
03:28 PM roycroft: 3 phase doesn't concern me - it's the mechanical bits that are more trouble than the electrical bits
03:29 PM roycroft: and i mostly dabble in the stock market, just because it's kind of fun and interesting
03:29 PM roycroft: if i lost everything i've invested, which i won't, i'd be fine
03:29 PM roycroft: i look at it like going to a casino - i spend money for entertainment, and if i happen to come out ahead in the end, so much the better
03:30 PM roycroft: if i actually do ever think i've actually figured it out i may change my strategy
03:30 PM Tom_L: i wonder if that one guy ever figured out the password to his bitcoins
03:30 PM roycroft: the guy who tossed his hard drive is still looking for it as far as i know
03:30 PM roycroft: and i still haven't found my pass phrase :)
03:31 PM roycroft: i still have some boxes to go through
03:31 PM roycroft: but when i started looking for that passphrase bitcoin had just broken $10,000 for the first time
03:31 PM roycroft: now it's over $50,000, so i don't mind if it takes me a bit longer to find it
04:29 PM Connor: okay, now I'm getting a bit irritated at the session manager. It's loading the nm-tray multiple times.. everytime I reboot.. it adds another one.
04:29 PM Connor: I've told the thing not to save sessions.
04:44 PM roycroft: so it turns out i don't have a drawing of the motor mount i actually made -just an older drawing that's useless, due to other design changes
04:44 PM * roycroft will have to do some more careful measuring now
04:46 PM _unreal_: roycroft, remember cut twice measure once
04:47 PM * JT-Shop tries for the 7th time to get this Telsa part to behave in SW
04:47 PM roycroft: in this case it's drilling/tapping, not cutting, that is involved
05:06 PM _unreal_: JT-Shop, I have no idea what you just said LOL
05:07 PM JT-Shop: wow I think I finally surface filled all the holes and knitted it into a solid piece... there's hope yet I'll figure out how to make the nest
05:08 PM XXCoder: ?
05:08 PM XXCoder: nest?
05:19 PM JT-Shop: a place you place a part and it puts the part in the orientation you want
05:19 PM Connor: I had to chmod -w the .cache/sessions directory
05:19 PM XXCoder: lol got example? i cant pictyre it
05:20 PM Connor: Can someone explain how I can make a button on the right hand side that can execute a system shutdown?
05:27 PM JT-Shop: no examples handy I don't think
05:28 PM Connor: would pyvcp or glade be better for it?
05:28 PM _unreal_: JT-Shop, 2d part or 3d part?
05:33 PM JT-Shop: https://gnipsel.com/images/briggs/moto_0064.jpg
05:33 PM JT-Shop: sorry it's a bit fuzzy but the cam shaft is sitting in a part nest
05:34 PM XXCoder: ahh nice
05:35 PM JT-Shop: I made 3 of those tab grinders for briggs
05:36 PM XXCoder: interesting video https://youtu.be/zVYk39RZcNg guy restores old bandsaw, and uses some printed parts to modernize it, like adding stop buttpn
05:42 PM roycroft: the guy is plugging a 2.3kw motor into a 120v 20a circuit - that does not give him any wiggle room at all
05:43 PM Connor: Anyone have any examples of executing a bash command via glade or pyvcp ?
05:43 PM XXCoder: roy interesting. i guess it'd have to use a breaker on its own, cant share anythign when its on'
05:44 PM _unreal_: hay JT-Shop I JUST PICKED up a PLC controller today
05:44 PM _unreal_: do you do stuff with plc controllers?
05:44 PM roycroft: yeah, i'm less than 4 minutes into that video and i cannot watch any more
05:44 PM roycroft: it's way too scary
05:44 PM roycroft: he's gonna kill himself some day
05:44 PM roycroft: probably soon
05:45 PM * roycroft decides to go mount his new motor, and wire it up to the vfd properly and safely
05:47 PM roycroft: and btw, the guy put a 15a plug on his 20a motor
06:09 PM Connor: Is the emc-users mail list still working? I've not gotten a email since 5/8
06:38 PM roycroft: i received a post from that list this morning
06:38 PM roycroft: several, in fact
06:38 PM Connor: Hm.
06:38 PM roycroft: but prior to that there had been none since the 8th
06:39 PM roycroft: so the list may have been down for a few days
06:39 PM roycroft: or people may have had better things to do for a few days
06:39 PM roycroft: oh, i take that back
06:39 PM roycroft: the posts i received today are from emc-developers
06:39 PM roycroft: somehow those posts are being merged into emc-users here
06:40 PM * roycroft probably needs to tweak his procmail recipes
06:40 PM roycroft: so yeah, my last post from emc-users was on the 8th
06:40 PM Connor: ok
06:40 PM roycroft: from brainfart@posteo.net
06:40 PM Connor: just trying to figure out glacevcp
06:41 PM roycroft: and when procmail doesn't know what to do with an email it sticks in in my inbox
06:41 PM Connor: yup. that was the last one I got.
06:41 PM roycroft: so if the list headers or whatever had changed i'd still have gotten the mails
06:42 PM roycroft: the volume of emails on that list has dropped, and often times it goes for a few days without a post
06:44 PM roycroft: dkim is broken on the emc lists, as well, which is rather annoying
06:44 PM roycroft: if you can't implement it properly, turn it off completely
06:46 PM _unreal_: t4nk_freenode, so when are you going to step out from behind the shackles of being only able to 3d print
06:46 PM _unreal_: ?
07:01 PM enleth: that feeling when the only piece of stock you have that's the right size is The Dread Unmachinium
07:48 PM Centurion-Dan2 is now known as Centurion_Dan
08:03 PM roycroft: i would definitely like to be able to print me some time
08:07 PM * roycroft is pondering making a huanyang vfd configuration spreadsheet, as he has several and is tired of misplacing the pieces of paper where he writes down the configuration parameters for each one
08:08 PM roycroft: my motor is mounted and wired up - the vfd settings are all i still need to do
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08:09 PM Tom_L: you get yours set then you can come tweak mine
08:21 PM roycroft: is yours a huanyang?
08:24 PM Tom_itx: https://www.alibaba.com/product-detail/310V-1-2kw-electric-motor-1200w_60737993181.html?spm=a2700.7724857.videoBannerStyleB_top.9.32c7751dTHUvzS
08:25 PM Tom_itx: http://en.lanjiukeji.com/product/754.html
08:26 PM Tom_L: i don't think so
08:40 PM XXCoder: roy LOl me too. i would love to print some time
08:44 PM roycroft: oh
08:44 PM roycroft: well i'm doing the spreadsheet, and i'm happy to share it when i'm done
08:44 PM roycroft: but it's specific to the huanyang vfds
08:44 PM Tom_L: i wrote out all my parameters
08:45 PM Tom_L: what the defaults are and what they're currently set to
08:45 PM Tom_L: this has a ramp up parameter and P & I for the pid settings
08:45 PM Tom_L: those were probably all i was gonna mess with
08:46 PM Tom_L: i may start with the ramp up time
08:47 PM Tom_L: that seems to be where it lags
08:47 PM roycroft: i typically only change a dozen or less parameters
08:47 PM Tom_L: alot of them i think are hidden on this one
08:48 PM Tom_L: no docs on them
08:48 PM Tom_L: it listed ~35ish parameters but only something like 14 are in the docs
08:49 PM Tom_L: accelerated speed is what it's called
08:49 PM Tom_L: 1-60000 and it's set at 6000
08:50 PM Tom_L: decelerated i suppose should be set the same
08:51 PM Tom_L: KP range is 0-99999 and it says the default is 1520 but it's set to 300
08:52 PM Tom_L: KI range is 0-99999 default is 320 and set to 100
08:52 PM Tom_L: that's quite a range
08:53 PM Tom_L: i'm assuming the lower number on the accelerated speed makes it quicker
09:02 PM roycroft: sadly, the parameters and their default values change on the huanyang vfds from firmware release to firmware release
09:03 PM roycroft: and there are almost 200 parameters on them
09:03 PM roycroft: it always takes me a while to program one
09:03 PM roycroft: that's why i'm improving the documentation
09:03 PM roycroft: my own documentation
09:04 PM Tom_L: they were nice enough to send me the docs they had but in chinese as well as a modbus diagnostic program also in chinese
09:20 PM Bleepshop: Tom_L: Now all you need is an intern who can read Chinese. LOL
09:21 PM Tom_L: it google translated fairly well
09:22 PM Tom_L: i doubt i'd use the program anyway
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09:35 PM enleth: FWIW, for induction motor VFDs, I've had excellent experience with the INVT brand, including English documentation quality
09:40 PM enleth: the GD10 series, up to 2.2kW, has a cool feature in that the built-in control panel can be detached and connected with a cat5 cable
09:41 PM Tom_L: that's kinda cool
09:42 PM enleth: so the VFD stays in the electrical cabinet, but its panel can be a part of the machine's operator panel
09:42 PM Tom_L: right
09:43 PM enleth: it's great for simple machines like grinders, where it can be the whole operator panel
09:43 PM XXCoder: lol Bleepshop check this out https://hackaday.com/2021/05/13/3d-printed-terminal-takes-computing-back-in-time/
09:43 PM enleth: 2.2kW is just spot on for such things
09:43 PM XXCoder: could use it to make old style cnc console lol
09:44 PM enleth: I have no idea if they make permanent magnet motor VFDs as well, but if they do and the manual is as good (should be available on their website), I would recommend trying them out
09:44 PM enleth: roycroft: ^
09:45 PM enleth: in fact, I had a much worse time working with a genuine officially branded Toshiba VFD, made in Japan and all the jazz
09:45 PM XXCoder: video kinda looks like old style tech demo vid too
09:46 PM enleth: configuration menu is a dumb joke, manual is all eng*r*ish
09:46 PM enleth: I'll take a chinese INVT over a Toshiba any day
09:48 PM enleth: the dumb joke being that they wanted to make it "easy" to set up, so the most important parameters are "named" instead of being numbered - problem is, they used a 7-segment display anyway and what it uses to display the "names" barely passes as letters
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09:48 PM enleth: in fact, in their ingenuity, they seem to have invented a few, as those symbols look nothing like any letter
09:49 PM enleth: so you're left with "mnemonics" that can't be pronounced because half the "letters" are who knows what
09:49 PM enleth: which is the exact opposite of a mnemonic
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09:51 PM Tom_L: you need a klingon translator for them
09:54 PM enleth: page 76 is where the fun starts: https://www.toshiba.com/tic/datafiles/manuals/NC3_Instruction_Manual_E6581595_Rev_4.pdf
09:55 PM enleth: they helpfully indicate those "names" using the 7-segment font in the manual
09:55 PM Tom_L: secret decoder manual
09:55 PM enleth: but good luck documenting a setup, or telling someone over the phone what to do
09:56 PM roycroft: i've made it up to parameter 150 out of just under 200
09:56 PM Tom_L: zoom call
09:56 PM roycroft: a good time to take a break and make dinner
09:57 PM enleth: "FNOd", "CNOd", which are supposed to be "FMOD" and "CMOD" but a 7-segment can't display an "M", so they use a tall "n" for "M", then there's "tHr" or maybe "tXr"?
09:57 PM enleth: that's the "EASY MODE"
09:58 PM enleth: ironically, the only part of it that a seven segment display can actually spell is the word "EASY" used to select this mode
10:20 PM Thorhian: Does anyone have any recommendations for a contactor that can handle 25-30 amps at 240V? I may eventually have a spindle motor that can eat up to 3.7KW.
10:29 PM XXCoder: wow https://newatlas.com/automotive/mahle-magnet-free-electric-traction-motor/
10:29 PM XXCoder: no more wear surfaces, and no more perment magnets
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10:43 PM roycroft: thorian: https://www.auberins.com/index.php?main_page=product_info&cPath=2_31&products_id=403
10:43 PM roycroft: i have purchased several contactors from them and i've been very happy with them
10:44 PM roycroft: none have ever failed
10:48 PM Thorhian: Thanks roycroft, I'm not very familiar with contactors, and I've been hearing contrary info about which kind I should get for my e-stop system to turn off my spindle motor and stepper PSUs. Mind if I pick your brain a bit more?
10:51 PM roycroft: i'm not an expert, so the pickings may be slim
10:53 PM Thorhian: Well, I was originally going to buy one of these: https://www.amazon.com/gp/product/B07WZQ17Y1/
10:54 PM Thorhian: However, some people in the PrintNC discord are saying all I need is one of these: https://www.amazon.com/Packard-C230B-Pole-Contactor-Voltage/dp/B001KGSJ74/
10:54 PM roycroft: that is similar to the one i linked to
10:54 PM roycroft: what are you controlling with this?
10:55 PM roycroft: the first one you linked to is 3 pole
10:55 PM roycroft: the second is 2 pole, as is the one i liked to
10:55 PM roycroft: because you said 240v, which is single phase
10:56 PM Thorhian: Right now it would be my 1.8 KW servo that acts as my spindle motor for my mill. I eventually want to upgrade to a 3.7 KW motor driven by a vector control drive. Yes, I know it's 3 pole, I figured it wouldn't hurt, but 2 pole is fine too. I'm just wondering why there is such a difference in price.
10:56 PM roycroft: the first one is shiny
10:56 PM roycroft: it's din-rail mount
10:56 PM roycroft: shiny costs money
10:57 PM roycroft: din rail mounting costs money
10:57 PM roycroft: but it really depends on the application
10:57 PM Thorhian: I'd also want to hook up the power supplies that feed my steppers. Sure it's shiny and DIN rail mounted (which I would prefer) but there has to be more than that.
10:57 PM roycroft: i usually use contactors in brewery control panels, which are enclosed, and not powered on when they are open
10:58 PM Thorhian: What do you use in your CNC machines? I thought contactors were common in an e-stop system.
10:58 PM roycroft: the cheaper ones are exposed, so you should not use them where there's a chance someone may access them while powered on
10:59 PM roycroft: my only cnc machine right now is a 3d printer
10:59 PM Thorhian: Oh oops lol
10:59 PM roycroft: but i'm using a contactor simliar to the one i linked to in the control box for the mill i'm converting (painfully slowly) to cnc
11:00 PM roycroft: however, in my brewing control panels, i use a latching contactor circuit for the e-stop
11:00 PM roycroft: it's low current
11:00 PM roycroft: and it in turn actuates the main power bus, via a high current contactor
11:01 PM roycroft: so the mains come in, feed the latching contactor, which controls the main power bus contactor
11:01 PM Thorhian: Yeah, I'm going to have my estop hooked up to 12V and it will control a smaller relay that is hooked up to mains 120V. That will control the contactor in my setup.
11:01 PM roycroft: you really don't need to be directly switching high current with an e-stop circuit
11:03 PM roycroft: you do not want to use a mechanical contactor in an application where it will cycle frequently
11:03 PM roycroft: it won't last very long if you d
11:03 PM roycroft: o
11:03 PM roycroft: in that kind of application you are better off with a ssr
11:04 PM roycroft: however, ssrs tend to fail closed, so when it fails, even though you think you've powered off the system, the ssr may still be passing current
11:04 PM roycroft: in brew control systems i cycle very frequently - sometimes several times/second, so i have to use ssrs
11:04 PM roycroft: this is for controlling heating elements with pid controllers
11:05 PM roycroft: i always put a mechanical contactor in circuit that feeds the ssr, so that when i kill the power i know the ssrs have no power
11:05 PM Thorhian: From what I know an SSR is not a great idea in terms of efficiency or cost in this case.
11:06 PM roycroft: that does not necessarily apply to your application, but it's interesting to know the advantages and drawbacks of each type of control
11:06 PM roycroft: ssrs are cheap
11:06 PM roycroft: but your e-stop circuit should not be directly switching high current devices
11:06 PM roycroft: so your e-stop would not cut power to the load side of the ssr
11:07 PM roycroft: it would cut power to the control side
11:07 PM roycroft: and if the ssr fails, it will usually fail closed, so cutting power to the control side will do nothing
11:07 PM roycroft: so it's not appropriate for what you're doing
11:08 PM roycroft: an e-stop is a control circuit, not a power circuit
11:09 PM Thorhian: I mean, the estop isn't directly controlling the contactor, it is technically controlling a relay that controls a 120V circuit to the coils of the contactor.
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11:09 PM roycroft: sure, simliar to what i do
11:10 PM roycroft: now i really insist on using latching contactor circuits for the main power, and tie the e-stop into that
11:10 PM Thorhian: Would a relay be closed if it failed?
11:10 PM roycroft: a mechanical contactor can fail open or closed
11:10 PM roycroft: an ssr almost aways fails closed
11:11 PM Thorhian: Hmmm, so I need something that will only fail open.
11:11 PM roycroft: it's hard to guarantee that
11:11 PM roycroft: but a good mechanical contactor won't fail if you maintain it (it requires very little maintenance)
11:12 PM buzzmarshall: e-stop is really more of a safety thing so it should be in the control circuit, tho putting it in on the supply is ok but for example if you were running on a microcontroller you don't really want to recycle the control by killing its supply, your really only interested in killing the control loop to the machine
11:12 PM roycroft: a mercury switch will never fail closed, as long as it's installed properly and as long as gravity still exists
11:12 PM roycroft: but mercury switches have their own problems
11:13 PM Thorhian: buzzmarshall: My estop won't kill my control (an RPi and mesa boards), just the power to the motors.
11:13 PM buzzmarshall: ya thats a good way
11:14 PM buzzmarshall: contactors tend to faill open as usually its the coil that goes but if something switching high voltage its posible to arc the contact bars to cause it to fail in the closed position
11:14 PM roycroft: my cnc computer for the mill is completely separate from the control box for the mill
11:15 PM roycroft: linuxcnc will not die when i hit the e-stop button :)
11:15 PM Thorhian: The 5V PSU and 12V PSU will be on no matter the state of the estop. However, the 36V stepper PSUs and the spindle servo drives will loose power when I hit the estop.
11:15 PM roycroft: if you don't maintain your contactor the points can fuse
11:15 PM buzzmarshall: ya thats a good consideration as well
11:16 PM buzzmarshall: the protecting the control box i mean
11:16 PM roycroft: but if the points are smooth to begin with and the contactor is not being pushed to or beyond its limits, it would be rare for it to arc and damage the points
11:16 PM roycroft: i tend to overspec contactors
11:16 PM roycroft: thorian asked for 20-30a, and i gave him a link to a 40a contactor
11:16 PM Thorhian: I mean, that tends to be a good idea, for safety.
11:17 PM buzzmarshall: i do as Thorhian as well and kill the driver ps supply rails
11:17 PM buzzmarshall: ya those utility type of contactors should do fine
11:18 PM buzzmarshall: if i was switching things with huge resistive loads like say heaters then i would be moving up in fla rating but for this type of stuff those you posted should be fine
11:18 PM Thorhian: So you approve of my future layout buzz lol? Not sure if I should rely on my cheap relay board to be in the estop loop for controlling the contactor now though.
11:19 PM buzzmarshall: sometimes the pricing difs represent how good the contact bars are
11:19 PM buzzmarshall: some use crappy alloys
11:19 PM buzzmarshall: others use high quality silver
11:19 PM buzzmarshall: tends to drive the price up a bit
11:19 PM roycroft: i'm typically switching up to 60a @240vac on a process control system that is in a very hot, very wet environment
11:19 PM roycroft: i know how to build those things safely :)
11:20 PM Thorhian: Silver is a really good conductor, but it is expensive lol.
11:20 PM buzzmarshall: nothing wrong with a good jolt once and awhile... at my age it keeps me awake
11:20 PM buzzmarshall: lol
11:21 PM Thorhian: So in my case of using 12V for my estop, what device would you recommend for controlling the contactor with instead of a cheap relay like I was planning on using?
11:21 PM roycroft: at the voltage and current i just mentioned, a "good jolt" means death, not waking up
11:22 PM buzzmarshall: 120 - 220 are the worst... ive been zapped a few times with 600 and some higher but the low like 120 is nasty
11:23 PM roycroft: it's not the voltage that will get you - it's the current
11:23 PM Thorhian: Define nasty? I believe some of the "freezing" has to do with the frequency of the AC we use.
11:23 PM buzzmarshall: yes thats true as a battery could do it
11:24 PM buzzmarshall: 120 will really make one do the newfy-2-step
11:24 PM roycroft: you can weld 1/2" thick steel with a car battery
11:24 PM buzzmarshall: and if its a good one its hard to let go
11:24 PM roycroft: not for a long time, but you can do it
11:25 PM Thorhian: Lol thats what I was going to ask, for how long?
11:25 PM buzzmarshall: for sure
11:26 PM buzzmarshall: ive seen dudes mix up the battery jumpers and have the cable clamp burn into the bumpers
11:26 PM Thorhian: XD
11:26 PM buzzmarshall: a good battery will draw a decent arc
11:28 PM Thorhian: So no suggestions on the estop to contactor control though? This isn't something that should be switching at high speeds seeing as it is a safety button.
11:28 PM Thorhian: high frequency*
11:31 PM buzzmarshall: normally with whatever im building at any given time i will just use a normal relay to interupt the output of the power supply or supplies supplying the motor drivers
11:32 PM buzzmarshall: which for me is usually around the 5v range and not much amperage
11:32 PM buzzmarshall: my idea of the e-stop basically is just to kill momentum in whatever form its happening
11:33 PM Thorhian: I was just going to control the contactor with one of the relays on this board: https://www.amazon.com/gp/product/B00LW2GA5Y/
11:33 PM buzzmarshall: but for others i quess there may be more involved
11:35 PM buzzmarshall: for most 3d printer engraver or small designs i can't see why they would not work
11:35 PM buzzmarshall: i use relays like that all the time
11:35 PM buzzmarshall: sometimes its just easier to buy boards like you just posted as they are cheap
11:37 PM buzzmarshall: the opto isolation is always nice especially if the circuit your trying to interupt or kill is tied to a gpio pin on a controller
11:37 PM buzzmarshall: a mechanical e-stop probably wouldn't matter but for 10 bux that board looks ok
11:38 PM buzzmarshall: only concern i could see would be if the load of the kill circuit excedes the relays rating on the switch contacts
11:40 PM Thorhian: Why would it? It will just control the contactor.
11:43 PM buzzmarshall: if your just using the relay as a pilot control to a another contactor then as long as the relay contacts are rated to handle the contactors coils amperage it would be find
11:43 PM buzzmarshall: which should be the case
11:44 PM buzzmarshall: but if the relay contacts themselves can handle the amp draw of the ps supply then the contactor's not really required but personally is still a probably good idea to go with
11:45 PM buzzmarshall: i should add i am just talking in general terms as i kinda came in mid conversation and not seen what your actually building
11:45 PM Thorhian: Hmmm, I better figure out how much the coil draws somehow. Shouldn't be too much at 120V. The simple relays are definitely not good enough for controlling the power flow of my 1.8 KW spindle motor lol
11:45 PM buzzmarshall: i just seen the links posted and thought what roycroft posted probably should be ok
11:46 PM Thorhian: If what Roy posted is okay I think this should be as well: https://www.amazon.com/Packard-C230B-Pole-Contactor-Voltage/dp/B001KGSJ74/?th=1
11:46 PM buzzmarshall: lol... ya that i wouldnt try
11:47 PM buzzmarshall: ya thats what i would normally call a service contactor
11:47 PM buzzmarshall: there used everywhere
11:47 PM Thorhian: Should be fine for cutting power to a 1.8KW motor drive or a 3.7 KW one as well right?
11:47 PM buzzmarshall: most rooftop hvac equipments loaded with them same as a ton of other equipment
11:48 PM buzzmarshall: you'd need to pay attention more the amps on the drive
11:49 PM buzzmarshall: vcc is one thing but amps is the big thing with contactor ratings
11:49 PM Thorhian: This would be at 240V, so potentially no more than 17 amps.
11:50 PM buzzmarshall: so anything in a contactor rating higher would be safe
11:50 PM Thorhian: Or 12 amps if I ran 3 400 W PSUs for my steppers.
11:50 PM Thorhian: Since it's a 2 pole I was gonna put the stepper PSUs on one pole and the spindle drive on the other.
11:50 PM buzzmarshall: higher is always ok its just how much you want to spend
11:51 PM Thorhian: It's 30 Amps per pole right?
11:51 PM buzzmarshall: typically thats the way they are rated
11:51 PM Thorhian: Okay, Ill order the cheap packard contactor then lol.
11:51 PM buzzmarshall: some contactors will have auxilary switches and they will be differnt
11:53 PM Thorhian: Looks like the relay board can switch up to 10 Amps as well, so that should be far more than neccesary for the driving the contactor.
11:53 PM buzzmarshall: ya i would think you should be good
11:55 PM Thorhian: I was getting that board originally for controlling solenoids from my mesa card but this is also a good use too lol.
11:57 PM buzzmarshall: usually i make my own boards but stuff like that is so cheap its just easier at times to buy them even if i only need part of its functionality
11:58 PM Thorhian: Well I don't know how to design PCBs yet so... I'd like to learn how though, along with the basics of making circuits in general useful for electronics like that.
11:59 PM Thorhian: I'm a Computer Science student learning how to make a CNC Mill on the side lol