#linuxcnc Logs
Feb 18 2021
#linuxcnc Calendar
12:00 AM roycroft: that's a broken website
12:07 AM roycroft: certificate mismatch
12:49 AM unterhaus_: I keep losing internet and then it comes back in a few minutes
12:49 AM XXCoder: sucks :(
12:49 AM unterhaus_: sometimes it goes out a little longer and rebooting it helps
12:50 AM unterhaus_: it really sucks because it's not that old, less than a year
12:50 AM XXCoder: you sure its not overheating?
12:50 AM XXCoder: some designs is really dumb and will overheat slowly if its horzional
12:52 AM unterhaus_: It has a base that actually holds it up, unlike some we have had in the past
12:52 AM XXCoder: give it a feel for hot spots
12:52 AM unterhaus_: I should figure out if the power supply is okay
12:52 AM XXCoder: check heat of that too
12:53 AM unterhaus_: there were problems with power saving that I'm wondering about
12:53 AM unterhaus_: but that only affected 2.4ghz wifi AFAIK
12:54 AM XXCoder: ok
12:54 AM unterhaus_: not sure how I would decide if hot spots were too hot, the processor is bound to be hot
12:59 AM XXCoder: yeah though plastic would be barely warm if any
01:06 AM unterhaus_: I'm a little suprised more stuff isn't offline because of Texas
01:06 AM unterhaus_: too hot there for server farms though maybe
01:07 AM XXCoder: dunno, though it certainly isnt now
01:07 AM unterhaus_: *usually
01:07 AM XXCoder: computers can run in quite cold envorment
01:07 AM XXCoder: only limiting factor is fans etc oil
01:07 AM unterhaus_: problem is when you put a whole batch of them together
01:08 AM unterhaus_: that's why google was going to put their server farms under the ocean
01:10 AM XXCoder: interesting
01:12 AM unterhaus_: my wife made 2 appointments for tomorrow so of course we're getting a big snowstorm
01:20 AM unterhaus_: client sent me a video of a refrigerator that throws a beer at you and said we should build one
01:20 AM unterhaus_: I told him I already had one
01:20 AM XXCoder: snowstorm ow. beer one lol
01:40 AM miss0r: mornin'
01:41 AM XXCoder: yo
01:41 AM miss0r: wow.. the temperature will go into the double digits tomorrow.
01:42 AM miss0r: lol. so within 10 days the range has been -20c to +10c
01:42 AM miss0r: That is impressive
01:42 AM miss0r: for these parts anyway
01:44 AM XXCoder: 40f here
01:44 AM XXCoder: erm 45f. which is 7,5c
01:44 AM XXCoder: *7.2c
01:45 AM miss0r: not too bad :]
01:45 AM XXCoder: yeah. MANY areas in middle of usa negative F
01:45 AM XXCoder: saw some -15f
01:45 AM miss0r: I need to get up my nerve to do a proper test turn in the cnc lathe today
01:45 AM XXCoder: -26c rough;ly
01:45 AM XXCoder: lathe rook soon?
01:46 AM miss0r: some things that are messing with me: 1) Where to zero tools, such as 60degree cutters and thread tools (z position)
01:46 AM miss0r: 2) mastercam makes me draw upside down, to get the x- correctly
01:47 AM XXCoder: bleh
01:47 AM miss0r: and that means I have to choose righthand tools instead of lefthand tools. This messes with me
01:47 AM XXCoder: i just designed cpap hose holder for bed. printing first part now
01:49 AM miss0r: nice
01:49 AM XXCoder: yeah
01:49 AM miss0r: bleh! Another costumer on the phone. This one, luckily, could wait this thursday of next week. Apparently one of their mazak machining centers is using 1.5-2liters of way oil a day
01:49 AM XXCoder: thats a lot!
01:50 AM XXCoder: i remember running cheap hurco
01:50 AM XXCoder: I had to refill oil tank each time
01:50 AM XXCoder: and keep below 2/3 fill
01:50 AM XXCoder: or it'll leak all of it out
01:50 AM miss0r: bah! Don't get me started on hurco!
01:50 AM XXCoder: i hate hurco
01:50 AM miss0r: mee too
01:50 AM miss0r: !
01:51 AM miss0r: I have a costumer with 5 of those. a three 3-axis and two 5-axis
01:51 AM miss0r: I've had to rebuild the table on the 5-axis twice. It REALY breaks when they do a small colission :) its too cheaply made.
01:51 AM miss0r: all the oil seals are more like crappy leather than actual seals ect
01:52 AM XXCoder: funny thing is I think haas is a step up from hurco, thats how bad it is
01:52 AM miss0r: haha yeah
01:52 AM XXCoder: i thought hurco was cool till I got job and ran older machines in general
01:52 AM XXCoder: then holy crap
01:53 AM XXCoder: i hated how hurco automatically homes spindle if you press hold
01:53 AM XXCoder: what if its a saw tool?
01:53 AM miss0r: Then stuff breaks
01:53 AM XXCoder: yep.
01:54 AM miss0r: also.. the design of their air driven hydraulic locking pumps were designed by an enraged 5-year old on meth
01:54 AM miss0r: they are a build in mean spirit and taste for vengance
01:55 AM miss0r: yup. I realy hate hurco... But on the other hand - they are good for buisness.. so its a complicated relationship I have with'em :D
01:57 AM miss0r: XXCoder: its funny. I've never met a sinlge person, operator or repairman, that actualy like hurco. I Think its one of those machines where only the one buying it initally like it for the price
01:57 AM XXCoder: lol
01:58 AM miss0r: XXCoder: So what are you up to today?
01:58 AM XXCoder: designing cpap hose holder
01:59 AM XXCoder: my bed is from ikea, bed board has sharp corners
01:59 AM XXCoder: so im making nice holder so hose can move smoothly
01:59 AM XXCoder: hose is expensive
01:59 AM miss0r: why do you want a hose in your bed? Do I even want to know? :D
02:00 AM XXCoder: you dont know what cpap is?
02:00 AM XXCoder: it helps me keep breathing in bed
02:00 AM miss0r: then no
02:00 AM miss0r: I did not know :)
02:00 AM XXCoder: and ya know, something medical means price * 10
02:00 AM miss0r: Oh, no doubt
02:01 AM XXCoder: hose is over 100 dollars I think lol
02:01 AM miss0r: woah
02:01 AM miss0r: well.. Then print away!
02:01 AM XXCoder: lol
02:01 AM XXCoder: plus vibration as i move enough to move hose is annoyomng
02:01 AM miss0r: yeah, if you can put hunting, gaming, medical or something else in front of the name the price goes up
02:02 AM XXCoder: hunting medical thingy that you can game on ;)
02:02 AM miss0r: woah woah. slow down there cowboy! ;) I don't have that kind of cash
02:02 AM XXCoder: lol
02:03 AM XXCoder: machine itself you can get cheap used car for similiar price
02:03 AM XXCoder: 1000 usd
02:03 AM miss0r: damn
02:04 AM XXCoder: yeah just glad I have insurance.
02:04 AM miss0r: I'm glad I live in a country where I don't have to pay for stuff like that. If I ever need one, the government will give me one
02:05 AM miss0r: Have you ever operated a cnc lathe?
02:05 AM XXCoder: yes but only as operator
02:05 AM XXCoder: barely change tool sizes
02:05 AM miss0r: okay.. hmm
02:05 AM miss0r: Did you ever setup tools?
02:05 AM XXCoder: not on cnc lathe
02:06 AM XXCoder: im pretty sure its similiar, you choose a common reference location
02:06 AM miss0r: Indeed. I'm there thus far
02:07 AM XXCoder: one trick you can do if have bunch tool change
02:07 AM XXCoder: have a rougher
02:07 AM miss0r: but setting up tools where their cutting point center is not the z- point of the tool illudes me
02:07 AM XXCoder: that one you dont have to repeatively set size. error range being too small to ever reach "final part" inside
02:07 AM XXCoder: and finisher that do
02:08 AM XXCoder: hopefully someone who knows cnc lathe can explain :)
02:09 AM miss0r: hehe I've been reading on online forums alot. But theres not a lot of information on cnc turret lathes
02:11 AM XXCoder: sometimes I wonder how common lathes is
02:11 AM XXCoder: shop i used to work at is very abnormal
02:11 AM XXCoder: they have over 20 lathes
02:11 AM miss0r: I can operate a manual lathe in my sleep. but theres stuff I have to unlean to make this cnc function proberly :D
02:11 AM miss0r: and none of them are manual? :D
02:12 AM XXCoder: theres also 2 manual
02:12 AM sensille: maybe you've setup the X-axis in an unusual direction?
02:12 AM XXCoder: huge one for tubes, and normal size one
02:12 AM miss0r: good. I hate going to a shop to do repairs that have no manual lathe. I always end up wanting to turn a new something for repairs
02:13 AM miss0r: sensille: I don't think. x- is moving the tool closer to the centerline. The issue with mastercam is, that is it divided into to four quatrants(spell?) where the top left one is where you can draw your contour to get x-.
02:14 AM miss0r: (when I swap x and y, that is)
02:14 AM miss0r: and my lathe has a operator side mounted turret.
02:15 AM miss0r: XXCoder: Don't you have a small lathe at home? if not, get one :D on a tool must have at home list, it ranges number three right after a bench vice or something :D (In my personal list that is)
02:15 AM XXCoder: nah only cnc router
02:15 AM XXCoder: well unless you count that ricious tiny lathe
02:16 AM miss0r: well... its too small if you can't rough a 5mm radius cut of CrMo without chattering
02:16 AM XXCoder: i dont think it can cut any but wood without chattering
02:16 AM miss0r: thats a good rule of thumb for the home gamer
02:17 AM XXCoder: CrMo?
02:17 AM miss0r: chrome nickel molybdenum steel
02:17 AM XXCoder: lol yeah the micro lathe cant touch that
02:18 AM miss0r: The stuff used for turbine impellar blades.
02:18 AM miss0r: I use that stuff for everything. its my goto material. if nothing else is specified, theres a good chance that stuff will hold up
02:20 AM miss0r: I have yet to try cutting ANY on the cnc lathe. I know it will not do a deep rough cut. I can use the manual lathe for that. but it has to be able to do single point threading in it - if not, I will sell it
02:20 AM miss0r: then it realy has no application here
02:20 AM XXCoder: cool :) strong steel eh
02:20 AM XXCoder: i guess highly resistant to rusting too
02:20 AM XXCoder: that nickel and chrome alloy
02:21 AM miss0r: well.. not compared to stainless steel 304/316
02:21 AM miss0r: but sure. it has *some* resistance
02:21 AM XXCoder: i guess its pretty machable too
02:22 AM XXCoder: stainless steel is just cruel on tools
02:22 AM miss0r: well yes and no :)
02:22 AM miss0r: its not as cruel on the tools, that is true. But unless you have the quite specific tools for it, and can run at a pretty substantial feed and DOC, you will get a proper birdsnest in there
02:22 AM miss0r: chipbreaking is an issue
02:24 AM XXCoder: for milling corncob maybe
02:24 AM XXCoder: lathe i have no idea
02:27 AM miss0r: XXCoder: These are some shafts/axles I have in regular production, made from said material: https://imgur.com/a/9OSUOBH
02:28 AM XXCoder: nicely machined
02:28 AM miss0r: Thank you
02:28 AM miss0r: all manual machined
02:29 AM miss0r: well.. This splines were done on the cnc mill, but with a manual dividing head
02:30 AM miss0r: bleh. enough browsing images of old projects :D I need to go figure out this lathe setup
02:31 AM XXCoder: :) have fun
04:19 AM Tom_L: morning
04:20 AM XXCoder: gey
04:21 AM XXCoder: *hey
06:24 AM JT-Cave: wow Tractor Supply bought Orscheln for $297m
06:25 AM XXCoder: tractor supply?
06:25 AM XXCoder: in least its not deere heh
06:26 AM JT-Cave: TSC prob is more midwest as is Orscheln
06:27 AM XXCoder: had to look up other company too. not common here :)
06:27 AM XXCoder: im sure ifI go out far enough ill see em but yeah
06:32 AM JT-Cave: looks like monday will be warm and sunny
06:33 AM XXCoder: nice
06:33 AM XXCoder: sadly today was last sunny day. rest will be rainy
06:52 AM JT-Cave: well I'm out of data for the month
06:57 AM XXCoder: 10 days ouch
06:57 AM XXCoder: more phone fiddling then
08:31 AM Tom_L: 2020 was hell. 2021 is hell freezing over :)
08:39 AM htasta: hey hou, could someone tell me if I can hook up these glass scales to my 7i76E or do I need an extra card for that?
08:39 AM htasta: https://www.aliexpress.com/item/32966880747.html?spm=a2g0o.detail.1000014.16.6d22642elr524Y&gps-id=pcDetailBottomMoreOtherSeller&scm=1007.33416.210122.0&scm_id=1007.33416.210122.0&scm-url=1007.33416.210122.0&pvid=fa600211-0252-4bb7-8619-2489bb9d0640&_t=gps-id:pcDetailBottomMoreOtherSeller,scm-url:1007.33416.210122.0,pvid:fa600211-0252-4bb7-8619-2489bb9d0640,tpp_buckets:668%230%23131923%2349_668%23888%233325%2312_23416%230%23210122%233_23416%234721%2321967
08:39 AM htasta: %23510_23416%234722%2321972%235_668%232846%238109%231935_668%232717%237562%23478_668%231000022185%231000066059%230_668%233422%2315392%23447_4452%230%23211409%230_4452%233474%2316498%23569_4452%234862%2324463%23840_4452%233098%239599%23877_4452%235108%2323442%2394_4452%233564%2316062%23195
08:39 AM htasta: ok, lemme short that link lol
08:39 AM htasta: https://tinyurl.com/4wdjwpfn
08:46 AM Tom_L: https://www.aliexpress.com/item/32966880747.html
08:46 AM Tom_L: you don't need anything after the ?
08:46 AM Tom_L: says ttl signal so it should be ok
08:49 AM htasta: cool thx. do you know if I can hook them up directly to the 7i76E or do I need to get an extra card?
08:51 AM Tom_L: i think it should be ok
08:55 AM htasta: cool, thx for the help, so im going to order those :D
01:23 PM JT-Shop: dang go inside for a light bulb and come back with a soda... where's the light?
01:40 PM roycroft: grr
01:40 PM roycroft: i just went to close an account at goldman sachs and was not permitted to do so online
01:40 PM roycroft: i was instructed to call them, and when i called the number i started getting spammed with ads that i could not stop
01:41 PM roycroft: i listened to the ads for about 4 minutes before i hung up
01:52 PM bjorkintosh: I didn't know GS did personal accounts.
01:56 PM roycroft: i have an investment account and a savings account with them
01:56 PM bjorkintosh: really? interesting.
01:56 PM roycroft: soon i'll have neither - i was trying to close the savings account, but after this incident i'm going to move my investment account elsewhere
01:56 PM bjorkintosh: damned vampire squid capitalist entity.
01:57 PM roycroft: which will be a pain in the butt, because they are going to charge me to transfer my investments
01:57 PM bjorkintosh: which incident? not being able to reach them?
01:57 PM roycroft: yes
01:57 PM bjorkintosh: ah. perhaps you have less than 10 billion in savings.
01:57 PM roycroft: so i'm going to have to sell everything off, get the cash, and reinvest it elsewhere
01:57 PM roycroft: yes, i did have somewhat less than that in savings
01:58 PM roycroft: right now i have $0 in savings with them, as i transferred it all out before attempting to close the account
01:58 PM bjorkintosh: I think that's the threshhold. too bad you're not a super-power supported dictator
01:58 PM roycroft: i'm actually very happy not to be that
01:58 PM bjorkintosh: it's a rare and small club.
01:58 PM bjorkintosh: very exclusive.
01:59 PM bjorkintosh: high risk though, I hear.
02:00 PM roycroft: the reason i closed the savings account, btw, is because they recently implemented a recaptcha "feature" on it
02:00 PM roycroft: the images were so tiny i could not see them clearly enough to discern what they were
02:00 PM roycroft: and when i magnified them they were too pixilated to see clearly, so i just moved my money elsewhere
02:01 PM roycroft: i would fail the recaptcha about 80% of the time, and then get locked out for a few hours
02:01 PM bjorkintosh: just based on that? they should have realized the UI was shite.
02:01 PM roycroft: apparently they did not
02:01 PM roycroft: at least not in a reasonable amount of time
02:02 PM roycroft: i put up with it for a couple months before i finally gave up
02:02 PM roycroft: i thought about calling them to discuss it
02:02 PM roycroft: but based on today's call attempt i'm glad i didn't bother
02:02 PM roycroft: anyway, they're getting a printed letter in the mail
02:02 PM roycroft: that is a quaint 20th century thing, i know, but i don't know how else to close the account
02:03 PM roycroft: it will be my first use of a forever stamp this year
02:03 PM bjorkintosh: don't they have an office near you?
02:03 PM roycroft: i don't know
02:03 PM roycroft: but in the first place, i'm not going to do something in person that can be done electronically during a pandemic
02:04 PM roycroft: and secondly, i'm not going to waste my time finding a local office and driving to it
02:04 PM roycroft: i've already written the letter - it will go out today
02:05 PM bjorkintosh: they're too big to fail.
02:05 PM bjorkintosh: they really don't care it seems.
02:05 PM roycroft: fortunately, i never linked the savings account there to an external funding source
02:05 PM roycroft: it was all push transactions from my credit union
02:06 PM roycroft: so they can't start charging me inactive account fees and just taking my money
02:06 PM roycroft: i don't know if the savings account is insulated from the investment account, but since i'm going to close that as well it doesn't really matter
02:19 PM JT-Shop: interesting just rapid an end mill through the part...
02:37 PM CaptHindsight: https://www.youtube.com/watch?v=kPrbJ63qUc4 30 minutes to touchdown on Mars
03:02 PM ziper: do i need to worry about flipping the reverse switch too quickly damaging the 3 phase motor?
03:03 PM roycroft: 3 phase motors can reverse intantly
03:03 PM roycroft: instantly
03:03 PM ziper: won't cause any problems with the extra forces?
03:04 PM roycroft: you're more likely to damage the switch than the motor
03:04 PM miss0r: well...
03:04 PM roycroft: folks have been power tapping with 3 phase motors on a mill by doing instant reversing for decades
03:04 PM miss0r: Depends on what is on the other end of said motor
03:05 PM roycroft: yes, but the motor itself would not suffer direct damage
03:05 PM miss0r: The motor itself can do it instantly. But if you have a gearbox with some build-up inertia, its another story
03:05 PM miss0r: but yeah. The motor will not suffer
03:05 PM roycroft: there may be collateral damage, agreed
03:05 PM miss0r: unless its a million year old :)
03:06 PM stinkpot is now known as gigas_cedar
03:06 PM miss0r: the windings will experience some serious deceleration forces. But a "modern" lacquered(spell?) winding will handle it without hesitation
03:06 PM JT-Shop: wow we made it 31F today
03:07 PM ziper: motor is from the 50s i think
03:07 PM miss0r: hmm. That does worrie me a bit then. Who made it?
03:07 PM miss0r: and what is the application?
03:08 PM ziper: atlas
03:08 PM ziper: a lathe
03:08 PM miss0r: hmm.
03:08 PM ziper: the manual doesn't say anthing about reversing
03:08 PM miss0r: I would hesitate a bit.
03:09 PM ziper: i usually do
03:09 PM miss0r: yeah. I do as well on my lathe. its somewhat more modern, but unless you realy need to, I would not reverse like that with it
03:10 PM miss0r: best practice is to let it wind down before restarting it in a new direction
03:10 PM miss0r: Alternately you could install a VFD and have a pretty steep deceleration curve - that will be better than a direct reverse
03:11 PM ziper: I have a VFD
03:11 PM ziper: i'm trying to decipher the manual
03:11 PM miss0r: hehe. I have a few minuts, do you have a link?
03:11 PM ziper: https://stevenengineering.com/Tech_Support/PDFs/45A11.pdf
03:11 PM miss0r: so, why do you want to direct reverse?
03:11 PM ziper: it had some logic inputs so I need to figure out how to get rid of those
03:11 PM ziper: I don't
03:12 PM miss0r: then what are you trying to acomplish?
03:12 PM ziper: if I needed to thread or something without disengaging the gearbox I could just use the clutch and then spin down and reverse
03:12 PM ziper: well, I don't have three phase so I need to at least get the motor spinning
03:12 PM miss0r: got'ya
03:13 PM miss0r: I would recommend that you use the clutch.
03:13 PM miss0r: and then have a reverse switch on the VFD, that will do the reverse somewhat gently
03:15 PM miss0r: so what is the goal here? What do you want it to do?
03:17 PM miss0r: ziper: ^
03:18 PM ziper: im figuring it out
03:18 PM miss0r: hehe
03:18 PM miss0r: Might I offer a propersition?
03:19 PM miss0r: propersition/suggestion
03:20 PM miss0r: if it was me, I would go for a diy panel with a potentiometer speed control knob, a turnswitch with forward, reverse & neutral(fixed positions). perhaps add a fault reset switch.
03:22 PM miss0r: I think we should be able to configure the VFD to show the current output frequency on the display or perhaps 50% of maximum output frequency. Some of them can even calculate speed, but that does not make much sence, as you probably have a gearbox on there.
03:22 PM ziper: turnswitch?
03:22 PM ziper: why not a regular 3 position?
03:22 PM miss0r: https://dk.rs-online.com/web/p/komplette-enheder-til-noglekontakt-og-vaelgeromskifter/3308672/?cm_mmc=DK-PLA-DS3A-_-google-_-CSS_DK_DK_Afbrydere_og_omskiftere_Whoop-_-(DK:Whoop%21)+Komplette+enheder+til+n%C3%B8glekontakt+og+v%C3%A6lgeromskifter-_-3308672&matchtype=&pla-342315378643&gclid=Cj0KCQiAvbiBBhD-ARIsAGM48bySYSKdNCV2YfLKooqffnXLhmrqeVI1u7npvmMbgVL9yhDUWc8XSAYaAmKIEALw_wcB&gclsrc=aw.ds
03:22 PM ziper: i'm going to try and use the speed controls as the backgears are missing teeth
03:23 PM miss0r: the link is for a two position. but I think we are on the same page here
03:23 PM ziper: what would be appropriate ramp times and low speed limits? .5 seconds and 20hz?
03:24 PM miss0r: I would say trial and error. But keep in mind those old motors are not build for the low speeds. So I would rather set it a bit higher
03:24 PM miss0r: and depending on the overhead of that VFD, you might have to have a longer ramp time so you do not exceed the current limit
03:24 PM ziper: i think it is a 2hp vfd and the motor is only 3/4
03:25 PM miss0r: Indeed. but keep in mind that a motor starting up directly, will draw 4xnominal current for the first second or so
03:26 PM miss0r: so, you'd need to have a ramp long enough to keep the current draw under what your VFD can supply. But it will only fault out, in which case you can just add time
03:26 PM miss0r: especially if you ever intend on having the clutch engaged while starting up the motor
03:26 PM ziper: but presumably if it is rated for 2hp, that rating includes the starting requirements for a 2hp motor? or does it only handle that 2hp with a slow ramp?
03:27 PM miss0r: most likely the latter
03:29 PM miss0r: a contactor rated at a *current value*,AC3 will take the motor startup current into account. the VFDs don't realy have to, because they have ramps to deal with such
03:29 PM miss0r: a good rule of thumb is: 2 seconds is fine, while 5 seconds is the upper limit(before you go nuts)
03:29 PM miss0r: so, if you can land it somewhere inbetween you're fine
03:29 PM ziper: is it bad to leave a VFD running on full and disconnect the motor from it with a contactor?
03:30 PM miss0r: yes!
03:31 PM miss0r: depending on the VFD it will either a) go into fault and need a reset or b) go byebye
03:31 PM miss0r: with a small VFD like this I would bet on option b
03:31 PM ziper: ok, thanks, the person that gave it to me told me it wouldn't be an issue but I didn't really believe him
03:32 PM miss0r: no worries. You have a good manual there. It lists all you have to do down to the last detail. If you take your time this project will be a breeze.
03:33 PM miss0r: You don't realy need the contactor. remember, if the VFD is running at full(theoretical here, obviously) and you engage the contactor the VFD would instantly be overloaded
03:33 PM CaptHindsight: go BOOM if you disconnect the motor leads while powered
03:34 PM miss0r: CaptHindsight: All electronics is powered by magic blue smoke. If said smoke escapes the magic stops working :D
03:35 PM miss0r: ziper: anyway. I need to get going. I hope I was some assistance. Cya
03:35 PM ziper: thanks bye
04:19 PM roycroft: and the magic smoke is unidirectional
04:19 PM roycroft: once it makes an escape it's impossible to stuff it back in
04:28 PM JT-Shop: I just turned down the opportunity to bid on a $150k machine...
04:30 PM unterhaus: JT-Shop, too much pressure?
04:34 PM JT-Shop: no, just wanting to slow down and relax a bit
04:51 PM roycroft: my bandsaw is not cooperating - i can't get the blade to track properly
04:51 PM roycroft: i'm going to try a different blade
04:51 PM roycroft: the tires are almost new, and i don't think they're the issue
04:52 PM skunkworks: band saw tracking is a great balancing act..
04:52 PM roycroft: i'll get it
04:52 PM roycroft: it may take some shimming and adjusting
04:53 PM roycroft: i get off work in 20 minutes, and that's my task for the shop today
04:53 PM skunkworks: the pigtails that came with my fiber splice boxes suck..
04:54 PM * roycroft thinks he can move one more website before the end of the day
04:54 PM skunkworks: But I bought some random terminated ends and they seem way better
05:00 PM JT-Shop: got a bit done on the dusk collection manifold https://gnipsel.com/images/wood-working/dust-collection/dust-manifold-02.jpg
05:00 PM JT-Shop: two more blast gates to make
05:30 PM Tom_L: JT-Shop, gettin there
05:39 PM JT-Cave: yea it's a bit long so I have to relocate the hole for the blower due to a bit of miscalculation
05:59 PM ziper: uh my lathe appears to be missing the brake/clutch mechanism
05:59 PM Tom_L: who stole it?
05:59 PM roycroft: fred flinstone used his feet for brakes in his car
05:59 PM roycroft: you could use your hands for brakes on your lathe
05:59 PM roycroft: just grab the chuck
06:00 PM roycroft: don't forget to yabba-dabba-doo
06:00 PM JT-Cave: lol
06:01 PM JT-Cave: time to call it a day here...
06:01 PM JT-Cave: roycroft, did you see the dusk collection manifold?
06:02 PM roycroft: i saw some pics while you were making it
06:02 PM roycroft: not the finished product
06:02 PM JT-Cave: today?
06:02 PM roycroft: no
06:02 PM roycroft: a few days aago
06:02 PM roycroft: before you glued the back on backwards
06:02 PM JT-Cave: https://gnipsel.com/images/wood-working/dust-collection/dust-manifold-02.jpg
06:03 PM roycroft: it's looking good
06:03 PM JT-Cave: thanks
06:04 PM ziper: is it ok to run a 3 ph motor at lower speeds without overheating so long as the load is kept low? Like threading?
06:04 PM roycroft: if the motor is designed for that, sure
06:04 PM ziper: and if it isn't?
06:05 PM roycroft: then the blue smoke might eventually make an escape
06:05 PM roycroft: and you will be sad
06:05 PM ziper: think i could use the ol palm temperature gauge and be ok?
06:06 PM roycroft: if i were varying the speed of a motor with a vfd i'd get a motor that's rated to run off a vfd
06:06 PM roycroft: you may do what you will
06:06 PM roycroft: and you may suffer no ill effects from having done so
06:07 PM roycroft: but i shall not endorse using a non vfd-rated motor in that application
06:14 PM bjorkintosh: palm temperature gauge. and safety squints!
06:48 PM enleth: ziper: low speed is one thing, VFD is another
06:48 PM enleth: ziper: low speed makes the integrated fan close to useless
06:49 PM enleth: VFD makes a motor heat up inductively unless the rotor is designed to prevent that and old ones aren't because no one knew it would be a problem back then
06:49 PM enleth: ziper: you can mitigate a part of the problem by installing an active cooling fan in place of the integrated one
06:50 PM ziper: oh, I see, so the VFD causes heating independent of the load
06:50 PM enleth: yes, it doesn't output pure sine waves, there's a ton of high frequency garbage in a VFD output
06:51 PM enleth: it literally turns the motor's windings and rotor into an induction stove and pot
06:51 PM ziper: so a VFD could cause unacceptable heating even at 60 hz?
06:52 PM enleth: it shouldn't, a non-VFD rated motor will be warmer but it should be able to cool itself enough to remain within acceptable limits
06:52 PM ziper: thanks
06:52 PM enleth: the problem of course is that only the stator is actively cooled, the rotor needs to transfer heat through the shafts and the stator
06:53 PM ziper: I hooked it up and the frequency was jumping around a lot from 55-65
06:53 PM enleth: but if you run an old motor slowly and don't add active cooling, you can and will burn it out
06:54 PM enleth: it might be worse with really old motors, I've heard, but I don't have any experience with those
06:54 PM enleth: oldest stuff I have is maybe 60s
06:55 PM enleth: those motors are more or less identical to the modern ones as far as general design is concerned
06:56 PM enleth: the 20s-50s motors, the bulby-cagey ones, were really different
06:57 PM ziper: bulby-cagey?
06:58 PM enleth: they have this distinctive ball-/bulb-ish shape, very short and wide, and often have the internals partially exposed
06:59 PM enleth: oh, there's one from very early 50s in the Bammesberger surface grinder, probably the oldest one I have, I wouldn't try running it off a VFD
07:00 PM ziper: I wonder if that is why the frequency won't stay stable
07:00 PM enleth: ziper: https://www.mechanicalmusicpress.com/registry/motors/cpmotors_p01.htm stuff like this
07:00 PM enleth: those open-sided pancake bulb things
07:01 PM enleth: I'm pretty sure the magnetics of those wide, flat rotors are completely different than in modern designs
07:02 PM enleth: ziper: that, or you have the VFD set up incorrectly
07:02 PM enleth: it needs to know a bunch of basic things about the motor
07:04 PM roycroft: around here, used good quality 3 phase motors are really cheap
07:04 PM roycroft: it might be worth looking into getting a more modern motor for the lathe
07:04 PM enleth: in fact, even new motors can be cheap and I can't really see anything seriously wrong with those cheap chinese ones
07:04 PM enleth: a 3-phase motor is one of the hardest things to screw up
07:05 PM roycroft: well, i might not totally agree there
07:05 PM enleth: I wouldn't put them in anything important, just in case
07:05 PM enleth: but a hobby lathe, eh, it'll work
07:05 PM roycroft: those imported 80mm spindles let their blue smoke out quite easily if the vfd is misconfigured
07:06 PM enleth: I'd consider the 3-phase spindles to be a completely different thing
07:06 PM enleth: they're way, way faster, for one
07:06 PM roycroft: i know you're talking about "standard industrial" 3 phase motors
07:06 PM roycroft: and those *are* pretty bullet-proof
07:07 PM enleth: yep
07:07 PM enleth: the cheap ones are probably best derated by 50% to be safe
07:07 PM ziper: Its not like I have any other use for an old, heavy, large, inefficient 3 ph motor anyway, so I figure I might as well see if it can perform acceptably before I go through the effort of replacing it
07:07 PM enleth: but if it works out of the box, it'll work
07:08 PM roycroft: they're so cheap that it's usually cheaper to buy a 3 phase motor + a vfd than to buy an equivalent horsepower single phase motor
07:08 PM enleth: this
07:09 PM enleth: ziper: what's the rated power on that motor?
07:09 PM ziper: 3/4
07:09 PM MrHindsight is now known as CaptHindsight
07:10 PM XXCoder: https://static.wikia.nocookie.net/southpark/images/c/c5/Captain-hindsight.png/revision/latest?cb=20170428085713 captin hindsight
07:10 PM roycroft: you should be able to get a 3/4hp 3 phase motor for about $20
07:11 PM enleth: a bit more and it'll be new and shiny, in the box straight from the factory
07:11 PM enleth: not that it matters much
07:12 PM roycroft: since this is for a lathe, i assume you want one that's abot 1725rpm
07:12 PM enleth: ziper: an old 3/4hp motor can power a bunch of stuff, such as Matthias Wandel's homemade woodworking machines, if you're into butchering tree carcasses
07:12 PM ziper: sure, but how would I power it?
07:13 PM roycroft: with a vfd
07:13 PM enleth: ah, you don't have 3 phases straight out of the wall?
07:13 PM ziper: then why wouldn't I just use it on the lathe if it worked with a vfd?
07:13 PM ziper: nope
07:13 PM enleth: sorry, I forgot it's not a standard thing everywhere
07:14 PM roycroft: it's almost unheard of in the usa except for industrial and farm service
07:14 PM ziper: and I suppose I could slave it to another 3 ph but at that point why not just get one that is VFD rated or a single phase motor?
07:14 PM roycroft: 3 phase power to a residence is very expensive to bring in, if even possible
07:14 PM bjorkintosh: that's why you move to a place that already has it.
07:14 PM bjorkintosh: what about a transformer?
07:15 PM roycroft: if you want variable speed then get one that's vfd rated
07:15 PM roycroft: but if you just want a working motor, you can likely get a 3-phase motor + vfd for less than the cost of a single phase motor
07:15 PM roycroft: but if you don't need variable speed, then you can use the old 3 phase motor that you have
07:16 PM roycroft: just power it with a vfd and use the vfd as just a phase converter, running at full frequency all the time
07:16 PM roycroft: that's probably the cheapest option
07:16 PM enleth: yeah, the fact that you guys treat rotary converters as something perfectly normal and obvious is mind-boggling to me, it's as if everyone had a rube goldberg machine in their backyard and saw nothing wrong or unusual about it
07:16 PM roycroft: and if you get the vfd to do that, and later decide you want variable speeds, all you have to do is buy a new motor
07:16 PM roycroft: and the vfd will be ready for you
07:17 PM CaptHindsight: uhmerica is all about big motors
07:17 PM roycroft: just be aware that if you use a vfd as a phase converter, you need to derate it
07:18 PM roycroft: so for your 3/4hp motor i'd get at least a 1.5hp vfd
07:18 PM enleth: CaptHindsight: if you can power them, that is
07:18 PM CaptHindsight: big noisy 3phase converter is gettiner dun
07:18 PM roycroft: if it's 3 phase in you don't need to derate it
07:18 PM roycroft: but if it's single phase in to 3 phase out you do need to derate it
07:19 PM CaptHindsight: even the step down transformers here are noisy
07:19 PM enleth: CaptHindsight: as one electricial once said, if you had 60 periods per second, you'd buzz a bit too
07:20 PM roycroft: and we do that bizarre split-phase voltage drop thing in this country
07:20 PM CaptHindsight: enleth: do you have a link to the CNC sewing machine that you converted?
07:20 PM CaptHindsight: I forgot to save it before
07:21 PM enleth: CaptHindsight: that had to be someone else, I think, I don't remember working on a CNC sewing machine
07:21 PM CaptHindsight: sorry must have my wires crossed
07:22 PM roycroft: did some of the blue smoke make an escape from the top of your head just now, capthindsight?
07:22 PM enleth: roycroft: I have quite a lot of exposure to the ways of US electrical systems through some youtubers I follow and I can point out a whole bunch of things that are wrong about it, split-phase being just the start
07:22 PM roycroft: if so, put your hat on quickly
07:23 PM roycroft: at least we don't have ring circuits here :)
07:23 PM enleth: that's the brits, they're different
07:23 PM roycroft: yes
07:23 PM roycroft: in so many ways
07:23 PM CaptHindsight: the old stuff was all Delta
07:23 PM roycroft: and that's not one of the good ways
07:24 PM roycroft: a lot of brits have tried to convince me that ring circuits are safe, but none have been able to do so to date
07:24 PM roycroft: and they're no longer permitted in the uk, so i think them in the know finally figured out that they're scary
07:24 PM CaptHindsight: power co's here starting swapping over to Wye in the 70's
07:27 PM enleth: roycroft: over here, the power distribution network is mostly of Soviet design (they pretty much ran the place and it's not like you can rebuild a power grid on a whim), but everything beyond the 15kV to 400V stepdown transformer is lifted straight out of Germany nowadays
07:28 PM enleth: with a few unfortunate French influences
07:30 PM enleth: wiring up German-style distribution panels might be a bit more involved than those vertical bus bar snap-in contraptions in the US, but I still greatly prefer that, there's way more flexibility in that system
07:41 PM skunkworks: https://www.youtube.com/watch?v=Xyf9TiBdMDA
08:03 PM Tom_L: skunkworks, when you probe the back side, how concentric does it come out? spot on or +- a little?
08:03 PM Tom_L: just curious how accurate probing is
08:05 PM XXCoder: yeah. ideal result (for probe) would be points in a circle would be on a plane with very little varation
08:09 PM skunkworks: Tom_L: pretty spot on.. The issue is that the spindle gets hot - 100degF - so as the spindle heats up - Y axis drifts up. (as the heat heats up)
08:10 PM skunkworks: when I probed begining and end - the hole 'moved' .002 (so off center by .001)
08:10 PM skunkworks: (as the heat travels down the head)
08:11 PM skunkworks: It really needs linear scales.
08:11 PM XXCoder: any possibility of cooling system?
08:12 PM skunkworks: I already take into account the spindle heating up in the Z axis and it is pretty accurate. (as the spindle grows - the z axis is adjusted)
08:13 PM skunkworks: I could use the same temp to adjust Y axis - but it would have to be delayed.. (it would be temp and time)
08:13 PM skunkworks: or mount a sensor lower on the head for better sensing of the temp creap.
08:14 PM skunkworks: Or bite the bullet and mound a decent linear scale on that axis.
08:14 PM skunkworks: loh
08:14 PM skunkworks: lob
08:16 PM Tom_L: well at least that's working
08:25 PM CaptHindsight: has anyone come across sin/cos to incremental output adapters?
08:25 PM CaptHindsight: I guess I need to make a batch
08:29 PM Tom_L: https://www.ti.com/lit/ug/tidua05a/tidua05a.pdf?ts=1613688291286&ref_url=https%253A%252F%252Fwww.google.com%252F
08:29 PM Tom_L: ?
08:31 PM Tom_L: https://www.motrona.com/en/products/signal-converters/interface-for-sincos-encoder.html
08:32 PM CaptHindsight: yeah they want >$400 for a working module
08:33 PM CaptHindsight: $50 in parts
08:33 PM Tom_L: soldering is a tedious task :)
08:34 PM Tom_L: did peter ever come up with something like that?
08:34 PM CaptHindsight: i don't think he has enough demand for them
08:34 PM CaptHindsight: I'll just have to build my own
08:35 PM CaptHindsight: I have many sets with mostly sincos 1V p-p output or current output
08:36 PM jdh]: I think andypugh made some with an avr or something
08:37 PM CaptHindsight: yeah, but that would be too slow for me, AMS and IC-Haus have chips for $10ea
08:37 PM CaptHindsight: just need power, passives and some connectors
08:41 PM CaptHindsight: I forget the already working types of encoder inputs to Mesa besides incremental
08:41 PM CaptHindsight: probably SPI
08:46 PM CaptHindsight: STMBL accepts sin/cos
08:52 PM CaptHindsight: https://www.ichaus.de/keyword/Interpolators
09:27 PM ziper: so now the hz stays rock steady while running
09:27 PM ziper: but about a quarter of the time instead of starting the motor just locks
09:33 PM roycroft: it is a very old motor
09:34 PM roycroft: it is weary, and occasionally finds it difficult to get motivated to get up and go
10:14 PM enleth: ziper: does it start if you (carefully!) give it a spin?
10:14 PM enleth: with a soft stick or something, not your hand
10:28 PM ziper: not if it has already locked
10:28 PM ziper: I haven't tried spinning it first and then engaging the vfd
10:28 PM enleth: that's interesting
10:29 PM enleth: other than a royally screwed up bearing that sometimes lands on the flat face of that one ball that cracked right in half, I can't think of a reason a 3-phase induction motor would do that
10:30 PM enleth: and it would definitely make a healthy racket if it were in that condition
10:30 PM enleth: so unless that motor sounds like a dumptruck full of scrap riding on bare rims over a cobble road, that's probably not it
10:32 PM enleth: one of the primary characteristics of this type of motor is that it can self-start in any circumstances
10:33 PM enleth: actually, wait
10:33 PM enleth: have you measured winding resistances?
10:33 PM enleth: maybe one of the phases is dying
10:33 PM enleth: that would explain the unstable frequency as well
10:37 PM enleth: if it's one of those 9-wire motors with center taps, it might be running only half of one of the windings or something like this
10:53 PM ziper: the frequency is rock solid now
10:53 PM ziper: it feels fine turning by hand
10:54 PM ziper: although the spindle bearings are rather poor
11:00 PM enleth: no idea then
11:00 PM enleth: it really shouldn't be doing something like this
11:23 PM FinboySlick: skunkworks: Always a pleasure to watch the K&T at work.
11:48 PM CaptHindsight: https://www.youtube.com/watch?v=i5BS3v9BsUQ Retrofitted Nowe Sterowanie Hauser CNC Sewing Machine SNA 3260 LinuxCNC by Toromatic