#linuxcnc Logs

Aug 25 2019

#linuxcnc Calendar

01:45 AM Choscura is now known as JewZeus
01:49 AM JewZeus is now known as Choscura
02:13 AM Deejay: moin
03:26 AM Sabotend_ is now known as Sabotender
06:23 AM Tom_L: morning
06:26 AM XXCoder: morning
06:27 AM jthornton: morning
06:38 AM Tom_L: storms all night and still raining
06:38 AM Tom_L: well since about 2:30-3
06:40 AM jthornton: pretty quiet here
06:40 AM jthornton: internet is super slow must be a rain drop in the sky...
06:41 AM Tom_L: tv drops at a hint of rain here but i've got cable internet
06:53 AM jthornton: our tv is pretty good in the rain but I don't think the internet antenna is pointed correctly
07:25 AM cgi: what is a good cad/cam software to teach kids? any suggestions? (for cnc/3d printing)
07:33 AM TurBoss: freecad maybe=?
07:36 AM XXCoder: 3d printer dont use cam, its "cam" is called slicers
07:36 AM XXCoder: i dont know whats good cam for kids to learn though
07:36 AM XXCoder: I played around a little with estlcam, its not bad
07:36 AM XXCoder: freecad does have it, its bit underdeveloped yet
07:37 AM cgi: I was trying fusion 360 - but it still looks complicated for kids
07:37 AM XXCoder: artcam maybe?
07:38 AM XXCoder: its more for engraving but its simpler? dont own that so cant definitely say so.
07:38 AM cgi: I was trying to find something that can be simple, but powerful and be used with 3d printers/cncs - fusion 360 fits that requirement
08:04 AM _abc_: Hi. Does anyone know if a precision (more or less) linear ball bearing, non recirculating, is better off with V grooves at 90 degrees or some other shape of the troughs? Also how would one cut this, I assume shape a cutter on a cutter grinder and use as fly cutter in a normal mill is easyest?
08:59 AM Elmo40: simple & powerful? that is a mix that doesn't happen in the wild...
09:00 AM Elmo40: _abc_, you have a drawing of what you are talking about? if it is 90degree then using the end of an endmill can make that shape. just hold the part on a 45.
09:01 AM Elmo40: if it is non-recirculating, what is it that rolls? a wheel? if so, then match the shape of the wheel.
09:36 AM _abc_: balls roll, they have a plastic frame with holes which keep them from escaping. Like in a drawer slide.
09:36 AM _abc_: Yes vertical milling with an end mill is also an option but likely much slower than a fly cutter with several arms.
09:54 AM skunkworks: jthornton: you have a very low power transmitter.. that is what stops working with any kind of interference.. even radar detectors
09:55 AM skunkworks: probably around 5 watts..
10:05 AM JT-Shop: skunkworks: the building has settled a bit since it was installed...
10:18 AM skunkworks: that doesn't help.. :)
10:24 AM jthornton: I know and I need to jack it back up and pour some concrete under the sagging corner
11:41 AM fragalot: 'sup
11:41 AM jym: morning
11:41 AM fragalot: just got the electronic leadscrew to a functional state on my lathe
11:42 AM fragalot: and it's quadrupled the maximum depth of cut I can take,... kinda logical but wasn't expecting that.
12:08 PM Choscura is now known as JewZeus
12:08 PM JewZeus is now known as Choscura
03:24 PM skunkworks: Yay - flood and coolant outlets hooked up
03:32 PM miss0r: shitfuck!
03:33 PM miss0r: apparently this bike wheel I am remachining (to fit another disk for the brake) does not take well to alcohol
03:33 PM miss0r: the powder coat is letting go !
03:34 PM miss0r: which is nice, since I promised the owner I would take care not to scratch it, as the coat is new...
03:34 PM miss0r: hmm.. I guess I kept my word - not a scratch in it
03:36 PM JT-Shop: alcohol should not touch powder coat...
03:36 PM miss0r: is this normal for powder coats? I
03:37 PM JT-Shop: I usually have to burn it off
03:37 PM miss0r: I know - right?!
03:37 PM JT-Shop: I think poor surface prep before the powder coat
03:37 PM miss0r: I'm telling'ya - it simply let go of the surface and bloated
03:37 PM JT-Shop: yea dirty surface
03:38 PM JT-Shop: I powder coat a lot of stuff and proper prep is super important
03:38 PM miss0r: but shouldn't the coat be "water tight" ? Sure it has let go a bit around the machined area, but also places a long way away from there
03:38 PM miss0r: hmm... I suppose it just ran underneath the surface...
03:38 PM JT-Shop: it should be so stuck that you have to burn it off with a torch
03:39 PM JT-Shop: there should be no underneath...
03:39 PM miss0r: hmm.. I guess I should tell the guy to get his money back then :D
03:39 PM JT-Shop: aye
03:39 PM miss0r: and remember to pay me :D
03:39 PM JT-Shop: lol
03:39 PM miss0r: meh - I'm only two hours into this project (complete now)
03:40 PM miss0r: I'll see what he has to say.
03:40 PM miss0r: (long time customer - won't ruin my rep because of this)
03:41 PM JT-Shop: yea there should be no way for powder coat to flake off if properly applied to a clean surface
03:42 PM miss0r: this is what I did; should you be curious: https://imgur.com/urGkFTH
03:43 PM miss0r: I had to move that surface down 12mm for him to fit it to X even though it was meant for Y
03:43 PM miss0r: also; that thing is waay too big for me to spin on the lathe, so the mill came in handy :)
03:44 PM JT-Shop: what kind of wheel is that?
03:44 PM miss0r: its for a motor bike
03:44 PM miss0r: all I know
03:44 PM miss0r: you are just looking at the center hub - where the disk is mounted
03:45 PM miss0r: assuming it was somehow another paint? is it reasonable for *any* paint to disolve with alcohol?
03:46 PM JT-Shop: I would not think any paint could be dissolved by alcohol
03:46 PM miss0r: I haven't run into this before either
03:47 PM miss0r: especially with such a short exposure
03:47 PM miss0r: 20 minuts or so
03:47 PM miss0r: maybe 30
04:04 PM MacGalempsy: anyone making chips today?
04:13 PM miss0r: Just about done for the night
04:13 PM miss0r: (sunday night here, still)
04:17 PM mr_boo: can linuxcnc handle feedback pulses from stepper motors?
04:17 PM JT-Shop: just packed up 60 pounds of spyder parts to ship to the anodizer tomorrow
04:17 PM JT-Shop: steppers are usually open loop but yes if you insist linuxcnc can
04:18 PM mr_boo: i found a couple of coded discs and photoresistor pairs from scrapped printers
04:19 PM mr_boo: strange that stepper motors don't have those discs incorporated considering how cheap the plastic disc and photoresistor pair is
04:20 PM miss0r: mr_boo: Not strange, as steppers do steps - so supposedly you already know where they are
04:21 PM JT-Shop: steppers don't have encoder feedback because you can't just add more power to speed up like you can with servos
04:21 PM JT-Shop: if your running at max step rate their ain't no more...
04:22 PM mr_boo: i heard that people loose steps even at normal operation
04:22 PM miss0r: you shouldn't loose steps.. err
04:22 PM miss0r: you shouldn't loose steps and call it 'normal operation'
04:22 PM mr_boo: but if steppers only loose steps when overloaded or overspeed then
04:23 PM JT-Shop: loose 1.not firmly or tightly fixed in place
04:23 PM miss0r: man its late.. I'll call it a night - see you around
04:24 PM JT-Shop: goodnight
04:29 PM CaptHindsight: mr_boo> i heard that people loose steps even at normal operation
04:30 PM mr_boo: is that untrue?
04:30 PM CaptHindsight: have you been in #reprap or where did you heardid this?
04:30 PM MacGalempsy: step loss?
04:31 PM MacGalempsy: from back here, I see the problem ;)
04:31 PM CaptHindsight: people also make buildings that fall down, bridges that break, airplanes that crash
04:31 PM JT-Shop: you normally don't lose steps...
04:31 PM MacGalempsy: I recall with some of the adjustable stepper drivers, that over dialling them will make the motor lose steps
04:31 PM CaptHindsight: a properly designed stepper system will not lose steps if operted within spec
04:32 PM mr_boo: that truly sounds great
04:32 PM Deejay: gn8
04:32 PM MacGalempsy: belts too tight? steps loss
04:33 PM CaptHindsight: accell to high, step loss, too much load , step loss, too high a speed, step loss,
04:33 PM mr_boo: i'm planning to build a cnc
04:33 PM MacGalempsy: now it sounds like a messed up dance routine
04:34 PM CaptHindsight: undersized stepper motor, step loss
04:34 PM mr_boo: i've got 3 of these motors https://www.banggood.com/HANPOSE-23HS7628-76mm-Nema-23-Stepper-Motor-57-Motor-2_8A-189N_cm-4-lead-CNC-Laser-Grind-Foam-Plasma-Cut-Engraving-Machine-p-1416710.html?utm_source=google&utm_medium=cpc_ods&utm_content=ysq&utm_campaign=ysq-content-sds-optical2-content&ad_id=328704017224&gclid=EAIaIQobChMIz_ygpvue5AIVw6iaCh3eFwnT
04:34 PM mr_boo: EAAYASAAEgK2NPD_BwE&ID=565876&cur_warehouse=CN
04:34 PM CaptHindsight: too much microstepping, step loss
04:34 PM MacGalempsy: picked up 2 seemecnc rostock max v2 machines today
04:34 PM CaptHindsight: https://www.motioncontroltips.com/faq-whats-the-difference-between-detent-torque-and-holding-torque/
04:34 PM MacGalempsy: and a filastruder. one rostock is still in the box
04:35 PM CaptHindsight: https://www.controleng.com/articles/stepper-motor-torque-basics/
04:35 PM CaptHindsight: https://www.machinedesign.com/archive/microstepping-myths
04:35 PM CaptHindsight: https://www.linengineering.com/news/in-the-media/how-to-use-microstepping-to-get-more-torque/
04:36 PM CaptHindsight: https://www.micromo.com/technical-library/stepper-motor-tutorials/microstepping-myths-and-realities
04:36 PM CaptHindsight: https://www.linearmotiontips.com/microstepping-basics/
04:36 PM pcw_home: JT-Shop: there's a guy on the forum ( hakan? ) that is is using linear encoder feedback with stepmotors and getting measurably better accuracy than open loop
04:38 PM CaptHindsight: pcw_home: one might have similar results after looking into his design and making the proper changes
04:39 PM CaptHindsight: the closed l;oop might be making up for his design or assembly errors
04:40 PM mr_boo: i like this idea for a cheaper alternative than ballscrew https://www.youtube.com/watch?v=vhodLP9ws0Q
04:42 PM pcw_home: Linear encoders fix a variety of issues especially with dovetail ways/stiction
05:06 PM JT-Shop: I wonder how hakan deals with that?
05:12 PM CaptHindsight: closed loop help wit the stiction, if it gets worse will he get bigger motors?
05:23 PM MacGalempsy: anyone try the kalecnc galvos?
05:24 PM MacGalempsy: mine finally came in
05:36 PM pmercado: Hi, packages are deb based only? opensuse user here.....
05:39 PM Tom_L: unless you build it i believe so
05:41 PM pmercado: :( ok thanks
05:42 PM pmercado: currently my dad bought as cnc 3018 pro, and he need help.... no idea about this topic so looking for newbies guides/tutorials/whatever. Seems need to calibrate it first
05:43 PM Tom_L: what control does it use?
05:43 PM Tom_L: or control software
05:44 PM pmercado: lol, no idea.... xD how to know it ?
05:45 PM pmercado: https://afel.cl/producto/kit-cnc-3018-pro-con-laser-2500mw-accesorios/?v=5bc574a47246 <---this
05:48 PM CaptHindsight: MacGalempsy: those are light show galvos, I'm usre they work and you can find them for less on ebay
05:50 PM pcw_home: Dovetail ways always have stiction and in conjunction with the torsional stiffness of the ballscrew and step motor stiffness results in significant static errors (and its not normally a stalling issue since step motor torque is highest at low speeds where slip/stick is an issue)
05:52 PM CaptHindsight: MacGalempsy: you can drive them wit the Mesa Analog Servo cards
05:53 PM CaptHindsight: pcw_home: whats the 4 out servo card number?
05:55 PM pcw_home: 7I33TA
06:26 PM jthornton: he didn't stay long lol
06:27 PM * jthornton calls it a day and relaxes before chow
06:31 PM jthornton: T-6 days till departure...
06:41 PM MacGalempsy: departure of what?
06:44 PM jthornton: depart Missouri for the Outer Banks
06:45 PM MacGalempsy: noice.
06:45 PM jthornton: now I'm departing the beer cave for the couch upstairs and some elk backstrap
06:46 PM MacGalempsy: still trying to figure out how to get this delta printer going before accidently crashing it
07:09 PM roycroft: hi folks
07:09 PM roycroft: i am confused again
07:09 PM roycroft: seems to be the story of my life any more
07:09 PM roycroft: i found a switch that would work for me, i think
07:09 PM roycroft: the voltage/current rating is fine
07:09 PM roycroft: but the horsepower rating is not
07:09 PM roycroft: and that is what confuses me
07:10 PM roycroft: it is rated at 16a 220/240vac
07:10 PM roycroft: but 2hp @220/240vac
07:10 PM roycroft: why the derating?
07:10 PM roycroft: https://www.mouser.com/datasheet/2/140/KJD17-346359.pdf
07:10 PM roycroft: that is the switch
07:10 PM roycroft: a 3hp motor, which i have, draws 9a @240vac and 10a @220vac
07:11 PM roycroft: so a 16a rated switch would seem to be fine
07:11 PM roycroft: do these people have bionic horses?
07:20 PM infornography: Have you considered using a relay?
07:20 PM roycroft: i'd rather not - space is tight
07:21 PM roycroft: but even if i could use a relay, i'd like to know why the horespower limit is derated from the voltage/current specification
07:21 PM roycroft: i *barely* have enough room to mount that switch
07:22 PM roycroft: it's also a somewhat harsh environment, and i'm concerned that a relay might not be reliable
07:30 PM roycroft: so from what i've just read, an inductive load will dump a high voltage back to the switch when the switch is turned off
07:30 PM roycroft: and the switch needs to be able to absorb that somehow, or the voltage might arc across the switch contacts
07:31 PM roycroft: since i'll be using this sitch to power a vfd, which will, in turn, power a motor, that should not be a problem as long as i always turn the motor off on the vfd before turning the mains switch off
07:32 PM pcw_home: If you are powering a VFD, its not an inductive load
07:33 PM pcw_home: mainly capacitive but it will have surge limiting circuitry of some kind
07:39 PM roycroft: yes
07:39 PM roycroft: the motor is the inductive load
07:39 PM roycroft: and it will dump the voltage back to the vfd
07:40 PM roycroft: that's why i think i'll be ok with that switch
07:40 PM roycroft: it would not directly control the motor
07:40 PM roycroft: even if i killed the mains at the switch before turning the motor off on the vfd, the vfd would absorb the voltage spike from the motor, and not feed that back to the switch
07:40 PM roycroft: so i'm good to go
07:41 PM roycroft: except i only have 0.017" clearance for the panel cutout, which is pretty tight
07:41 PM roycroft: but i do have a flex-shaft tool and some nice, agressive burrs
07:41 PM roycroft: so i can make more clearance if need be
07:43 PM Tom_L: roycroft, seems you just answered your own question. derated due to back emf
07:43 PM Tom_L: for inductive loads
07:44 PM Tom_L: no inductance, no need to worry
08:32 PM roycroft: yes, i did, tom_l
08:33 PM roycroft: i had to read a bit and then give it a quick think
08:34 PM roycroft: i guess when switches are rated the amperage rating is for resistive loads and the horsepower rating is for inductive loads
08:34 PM roycroft: if they would just say "resistive load current" and "inductive load current" it would have been clear from the get-go
08:50 PM _unreal_: hehe speaking of switches. I had a WTF a while ago. was working on a boat and found that the float switch for the bilge pump was rated at 10amps with a 20amp bilge pump
08:50 PM _unreal_: I was like HAY LOOK a fuse switch
08:50 PM _unreal_: or fusable switch
08:50 PM _unreal_: :)
08:53 PM roycroft: it seems i'm unusual in that i actually look at specifications for products i buy to ensure they will be suitable for the application at hand
08:54 PM roycroft: most folks these days buy what is shiny and don't think about anything else
08:54 PM roycroft: such as the boat person :)
08:55 PM roycroft: that switch probably was not purchased because it was shinky though
08:55 PM roycroft: shiny
08:55 PM roycroft: it was probably purchased because it was either cheap, available, or both
09:11 PM _unreal_: I like shiny
09:11 PM roycroft: don't get me wrong
09:11 PM roycroft: i like shiny too
09:12 PM _unreal_: I'm sure the person who purchased that setup was a moron
09:12 PM roycroft: but shiny is not the sole determinant when making a purchase
09:12 PM _unreal_: float switch, bilge pump. ii'm good
09:12 PM _unreal_: specs who the fuck needs those
09:12 PM _unreal_: should have seen all the BS that was going on with that boat
09:13 PM _unreal_: hehe
09:13 PM roycroft: it has to be both shiny and suitable for the application
09:15 PM XXCoder: cost of ownership should be a concern also lol
09:18 PM _unreal_: do any of you use fusion360?
09:19 PM Tom_L: i looked at it briefly but no
09:19 PM Tom_L: a few ppl here use it
09:20 PM _unreal_: its totally fucked up suddenly
09:20 PM _unreal_: I have not touched it then suddenly all the menus have moved or changed everything has changed.
09:20 PM Tom_L: not surprising
09:20 PM _unreal_: I assume it's an "update"
09:20 PM _unreal_: and nothing works now
09:20 PM _unreal_: I was JUST starting to get the hang of ti
09:20 PM _unreal_: it
09:58 PM roycroft: i tried fusion360 briefly
09:58 PM roycroft: but i don't use software that calls home all the time
09:59 PM roycroft: i saw nothing in fusion360 that persuaded me to change my thinking on that
09:59 PM roycroft: i already have high-end parametric cad software
09:59 PM roycroft: but if you don't mind stuff that calls home, fusion360 looks quite capable and is fairly easy to use
10:18 PM _unreal_: roycroft, was...
10:18 PM _unreal_: they just changed all the menus
10:18 PM _unreal_: EVERYTHING
10:18 PM _unreal_: I cant find anything
10:19 PM _unreal_: and functions are not working as they use to
10:19 PM _unreal_: very annoying
10:21 PM Tom_L: _unreal_, it's not really mature software yet
10:21 PM _unreal_: considering how muchthey just changed the menus VERY imature
10:22 PM Tom_L: they're just trying to gain market share by giving it out and getting you hooked
10:23 PM Tom_L: catia changed their front end recently too and also went cloud based
10:23 PM Tom_L: they're all gonna do it if they haven't already
10:23 PM _unreal_: I use design spark mainly
10:23 PM Tom_L: fortunately the backbone of it is the same
10:24 PM _unreal_: I was starting to get good a it till they just fucked all the menus up
10:24 PM _unreal_: with in the past what 2+ weeks
10:24 PM Tom_L: have you looked on their forum for info about it?
10:24 PM _unreal_: I've alrady sent them a LOT of hate mail
10:25 PM Tom_L: maybe they have tutorials in place to help
10:25 PM _unreal_: this like the 3rd or 4th major menus rearrangement in like 4 years looking at the youtube videos of HOWTO's
10:26 PM Tom_L: expect more. like i said it's not that mature yet
10:26 PM roycroft: tom_l: i stopped upgrading adobe cs when they went cloud-based
10:26 PM _unreal_: thats not the point. you dont give the ablity to generate your OWN menus setup and then force change EVERYTHING on every one
10:26 PM roycroft: i'll use cs6 until i no longer have a machine that will run it
10:27 PM roycroft: and then i just won't use their stuff
10:27 PM Tom_L: i could tell you a story about adobe but it's hardly worth it
10:27 PM roycroft: i used to give the money every time they came out with a new version of their stuff
10:27 PM roycroft: now they get no money at all from me
10:28 PM roycroft: fortunately things like the gimp have matured quite a bit over the years
10:28 PM roycroft: should the adobe stuff break i have open source alternatives now that are actually useful
10:28 PM Tom_L: i've even stopped using their reader
10:29 PM roycroft: mac os has pdf built-in
10:29 PM roycroft: i use preview for almost everything
10:29 PM Tom_L: i've got feelings about apple too
10:29 PM roycroft: i still use acrobat pro for some things though
10:29 PM _unreal_: heh
10:30 PM roycroft: mac os is becoming more like ios
10:30 PM _unreal_: I use to LIVE for page maker
10:30 PM roycroft: and less like unix
10:30 PM XXCoder: adobe means slow and expensive'
10:30 PM _unreal_: I had ripped versions of PM
10:30 PM roycroft: the adobe apps perform better than most open source analogs
10:30 PM _unreal_: well FULL version. because they had the broken serial gen
10:31 PM Tom_L: didn't mean to start a software war here... just voicing observations
10:31 PM _unreal_: I see no war?
10:31 PM roycroft: yes, all i see is observations
10:31 PM Tom_L: for lack of a better term...
10:31 PM _unreal_: just a bunch of middle + aged guys reminiscing
10:32 PM roycroft: and i'm not promoting anything
10:32 PM roycroft: or dissing anything
10:32 PM roycroft: just saying what i use and why
11:01 PM CaptHindsight: what do you guys use for Fusion360 file names? Iran_weapon_004, Notabomb_xyz, sekratzdevices,
11:01 PM CaptHindsight: I'm sure they don't poke through the files saved :)
11:03 PM roycroft: if you're concerned about metadata like that then name them by drawing number and be boring :)
11:05 PM roycroft: just don't store your drawing index in the cloud if you do that
11:48 PM _unreal_: roycroft, what could go worng