#linuxcnc Logs

Sep 19 2022

#linuxcnc Calendar

12:53 AM Deejay: moin
01:36 AM pere: hi
03:26 AM andypugh: mrec: No, As we want to measure F-error in the A position.
04:18 AM Tom_L: morning
04:50 AM JT-Cave: morning
05:50 AM -!- #linuxcnc mode set to +v by ChanServ
05:53 AM JT-Cave: hmm debian 12 knows my monitor so I'll stop there I think
06:30 AM boozeman[m]: Good afternoon (at least EEST timezone)
06:31 AM XXCoder: 4 am it checks out]
06:35 AM boozeman[m]: Shift change then 😁
06:47 AM -!- #linuxcnc mode set to +v by ChanServ
06:48 AM JT-Cave: hmm I guess it's onward and upward the mb nic stopped working after a reboot
06:53 AM Tom_L: shoot for the moon
06:54 AM Tom_L: that's how buster acted on the rpi
06:56 AM JT-Cave: trying to get rid of the dreaded ethernet time out error with mesa cards has proven to be pia
07:24 AM -!- #linuxcnc mode set to +v by ChanServ
08:04 AM mrec: andypugh: maybe you have some time tomorrow to go through my setup here? everything works but I think it does not comply with your initial idea how it should be set up.
09:10 AM sandraeb[m]: https://t.me/+vndBSzzn3VdhNGJh
09:10 AM sandraeb[m]: I'll 20 people on how to earn $10,000 or more in just 3day's from the crypto market.but you will pay me 10% commission when you receive your profit. if interested send me a direct message, for more information... Contact via telegram
09:10 AM sandraeb[m]: https://t.me/+vndBSzzn3VdhNGJh
09:29 AM JT[m]1: Hmm
10:11 AM JT[m]1: Gotta redo how I deal with the ini file to only update values from mesact, now I write over the ini
11:01 AM Tom_L: sounds like alot more file searching
12:47 PM roycroft: in the back of my van are 17 long postal letter trays, containing over 5000 ballots
12:47 PM roycroft: the ballots are not in any particular order other than semi-randon
12:47 PM roycroft: random
12:47 PM roycroft: a member just emailed me informing me that he moved a few months ago, and wants me to go find his ballot and sent it to his new address instead of his old one
12:49 PM roycroft: i had to suppress my inner python and refrain from responding "can do, but won't"
12:50 PM roycroft: i'm not sure i could pull that phrase off as well as john cleese anyway
01:48 PM Tom_L: roycroft, wouldn't he just make a change of address at the post?
02:18 PM roycroft: he claims to have done that, but is concerned that mail forwarding takes a long time
02:18 PM roycroft: which it often does
02:19 PM roycroft: i told him it's too late to find it, and that it's going in the mail today (and i just got back from the post office, so it's in the mail)
02:20 PM XXCoder: id say same
02:20 PM roycroft: if he doesn't get it by october 1st, we'll void the ballot and send a new one to his new address
02:20 PM XXCoder: just no way
02:20 PM roycroft: ballots are not due until october 22nd so there's plenty of time to reissue it
02:21 PM Tom_L: he just want's to sway the vote!!
02:22 PM roycroft: our candidates' forum isn't until october 2nd
02:23 PM roycroft: i expect most people will not vote until after that
03:03 PM XXCoder: CaptHindsight[m]: yeah someone recommanded other to buy formlabs sls powder pa11 at 116 usd per kg lol
03:04 PM XXCoder: isnt it like 40-50 per kg elsewhere?
04:12 PM JT-Shop: boozeman[m], bug is squashed
04:47 PM Tom_L: python expert now.. opened a file and printed the contents :)
04:48 PM Tom_L: oh.. and closed it
04:51 PM JT-Shop: in a with loop?
04:51 PM Tom_L: oh hell no
04:51 PM Tom_L: that's way too advanced :)
04:51 PM JT-Shop: lol
04:51 PM Tom_L: alot of the syntax is backward from what i'm used to
04:52 PM Tom_L: f.close() fclose(f)
04:52 PM Tom_L: for example
04:53 PM JT-Shop: with open('filename.txt', 'r') as file:
04:53 PM Tom_L: how do you address the 2nd dimension in a 2 dimensional array?
04:53 PM JT-Shop: file.read()
04:54 PM JT-Shop: not sure python has and array data type
04:54 PM Tom_L: it does i think
04:55 PM JT-Shop: that's a list really not an array
04:55 PM JT-Shop: cars = ["Ford", "Volvo", "BMW"]
04:55 PM Tom_L: array = ["x","y","z"]
04:55 PM JT-Shop: cars[0]
04:55 PM JT-Shop: that's a list
04:55 PM JT-Shop: cars[1] cars[2]
04:56 PM Tom_L: just a different way of accessing memory
04:56 PM JT-Shop: https://www.w3schools.com/python/python_lists.asp
04:56 PM Tom_L: yeah i've used them before
04:56 PM Tom_L: and have it open
04:58 PM -!- #linuxcnc mode set to +v by ChanServ
04:58 PM Tom_dev: List = [ [1, 2], [2,5], [5,1] ]
04:58 PM Tom_L: that's what i'm used to calling a multidimensional array
05:09 PM JT-Shop: that's a list of lists
05:09 PM Tom_L: heh
05:10 PM Tom_L: i got into codeblocks but not real oops
05:11 PM JT-Shop: >>> a = [[1,2],[2,3],[3,4]]
05:11 PM JT-Shop: >>> a[0]
05:11 PM JT-Shop: [1, 2]
05:11 PM JT-Shop: >>> a[0][1]
05:11 PM JT-Shop: 2
05:11 PM Tom_L: codeblocks are rather powerful
05:11 PM JT-Shop: I don't do oop de poop
05:11 PM Tom_L: i consider python oops
05:11 PM JT-Shop: I just hand code
05:11 PM JT-Shop: oop makes sense sometimes
05:12 PM XXCoder: its amazing if well done
05:12 PM JT-Shop: how is that?
05:14 PM XXCoder: I remember some ugly oop code from college lol
05:14 PM JT-Shop: lol
05:14 PM XXCoder: most of mine was pretty good
05:19 PM JT-Shop: for what I do oop only complicates the program, oop is only worth the trouble if your creating several instances of a class in your code
05:21 PM JT-Shop: >>> class pets():
05:21 PM JT-Shop: ... pass
05:21 PM JT-Shop: ...
05:21 PM JT-Shop: >>> a = pets()
05:21 PM JT-Shop: >>> b = pets()
05:21 PM JT-Shop: >>> a == b
05:21 PM JT-Shop: False
05:21 PM JT-Shop: >>> a
05:21 PM JT-Shop: <__main__.pets object at 0x7fc489502c20>
05:21 PM JT-Shop: >>> b
05:21 PM JT-Shop: <__main__.pets object at 0x7fc4893b3b20>
05:25 PM XXCoder: yeah seperate copies
05:59 PM JT-Shop: https://rushter.com/blog/python-garbage-collector/
06:03 PM XXCoder: interesting
06:15 PM JT-Shop: threading is interesting, angry ip scanner uses 100 threads and as one completes it adds another until all ip addresses on the subnet are scanned
06:16 PM XXCoder: yeah its nice
06:17 PM JT-Shop: https://github.com/jethornton/pyqt5-ip-camera
06:17 PM JT-Shop: I need to figure out how to recover from an error polling the cameras...
06:17 PM XXCoder: what langiuage you using?
06:18 PM JT-Shop: python
06:18 PM JT-Shop: #!/usr/bin/env python3
06:18 PM XXCoder: doesnt it have try catch?
06:18 PM JT-Shop: first line
06:18 PM JT-Shop: yes
06:18 PM XXCoder: so you can handle such errors
06:19 PM XXCoder: you probably can just have default image for failed poll
06:19 PM XXCoder: (if its to get image from camera)
06:19 PM JT-Shop: it uses QThread for each camera
06:20 PM JT-Shop: https://github.com/jethornton/pyqt5-ip-camera/blob/master/camera.py#L36
06:21 PM XXCoder: error happens with isOpened()?
06:22 PM JT-Shop: I'm not sure, I get a variety of errors but once an error occours the camera is not polled again
06:22 PM XXCoder: im very weak on threads so not too ture
06:22 PM XXCoder: *sure
06:23 PM XXCoder: is cap released after BREAK is called?
06:23 PM JT-Shop: I need to do a single or double so the code is slimmer and study it more but first I need to change how I update the ini file in mesact
06:23 PM XXCoder: if not might be cause of it not resuming at all
06:24 PM JT-Shop: I think so
06:24 PM JT-Shop: or the error is inside if ret:
06:25 PM JT-Shop: https://github.com/jethornton/pyqt5-ip-camera/blob/master/camera.py#L149
06:25 PM JT-Shop: that's what needs to be restarted after an error
06:25 PM XXCoder: it probably just went and ended thread after an error
06:25 PM * JT-Shop wanders inside for the night
06:25 PM JT-Shop: I think so
06:26 PM XXCoder: well hacky solution (I think) is timer to poll all 4 cameras, see if thread is active
06:26 PM XXCoder: if not, restart it
06:27 PM XXCoder: not sure how to do thread check, not my forte and havent seriously programmed for years
08:01 PM roycroft: hello, folks
08:01 PM roycroft: i'm not accustomed to running a vfd/motor at a really low frequency
08:01 PM roycroft: i'm looking at an application where i might need to do so
08:01 PM XXCoder: hey
08:02 PM roycroft: if i get the right motor, with the possible combination of pulleys, i'll need to run it at about 20% of rated speed
08:02 PM roycroft: i'm thinking that might not work too well
08:02 PM roycroft: it would either stall out completely, or have very little torque at that low a frequency
08:03 PM roycroft: is that right? are there vfds that can run at really low frequencies and still provide decent torque?
08:05 PM roycroft: i'd like to have variable speed, but if it's not feasible to do this with a vfd i could get a motor with a gear reduction box that would provide a single speed that i could live with
08:09 PM CaptHindsight[m]: fractional HP? or real man motors?
08:10 PM roycroft: i need a 1hp motor for this
08:10 PM roycroft: it's for a bandsaw that i'm repurposing to cut metal
08:10 PM CaptHindsight[m]: how many HP or Watts? How many RPMs?
08:10 PM roycroft: currently it runs at about 3300 sfm, and i need to reduce that to ~250sfm
08:11 PM XXCoder: wouldnt gearing solve that?
08:11 PM roycroft: i can upsize one of the pulleys, and i can replace the 1720rpm motor with a 1200rpm motor
08:11 PM roycroft: but that gets me down to about 1700sfm
08:11 PM roycroft: so i need some more help :)
08:12 PM roycroft: unfortunately there's not enough room to reduce it to where i need with pulleys
08:12 PM CaptHindsight[m]: 1720 rpm - 3300sfm and you need 250
08:12 PM roycroft: right
08:12 PM roycroft: but the current motor is single phase
08:12 PM roycroft: i do plan on replacing it
08:12 PM roycroft: with a 3 phase motor, and it's not hard nor expensive to come by a 1200rpm 1hp 3 phase motor
08:13 PM CaptHindsight[m]: 13 x speed reduction
08:13 PM roycroft: the pulley attached to the drive wheel is currently 6", and i can increase that to 8"
08:14 PM roycroft: the motor pulley is 3", and i'd prefer not to make that any smaller, but i could go down to 2" if i had to
08:14 PM CaptHindsight[m]: 1720 / 13 = 573
08:14 PM roycroft: that wouldn't gane me nearly enough
08:14 PM CaptHindsight[m]: heh wait
08:14 PM roycroft: gain
08:14 PM roycroft: the drive wheel is 14", and that cannot change
08:14 PM CaptHindsight[m]: 1720 / 13 = 132
08:15 PM CaptHindsight[m]: 14:3 and can go 14:2
08:15 PM roycroft: those gear reduction boxes are expensive
08:16 PM roycroft: but the bigger concern is that most of them move the shaft 90 degrees, and that would cause some problems
08:17 PM CaptHindsight[m]: 14 : 3 now but need closer to 14 : 2 : 2
08:17 PM * roycroft may just give up on the whole idea
08:17 PM roycroft: i have a 7x12 bandsaw that i can set up in vertical mode, but it's not fun
08:18 PM roycroft: i made a table for it that's bigger than the stock table, but it's still not fun
08:18 PM roycroft: having a dedicated vertical metal bandsaw would be nice
08:20 PM Rab: Something's coming back to me about somebody who made a gearhead lathe using a car transmission.
08:20 PM CaptHindsight[m]: do you have a pic of the drive wheel and where the motor fits?
08:20 PM CaptHindsight[m]: and the space between and near
08:21 PM CaptHindsight[m]: Rab: do you pick your paint?
08:21 PM CaptHindsight[m]: oh and ch382 is working well, it might have just been bad boards all along :)
08:22 PM CaptHindsight[m]: bad parts , assembled improperly, bad qc etc
08:22 PM flyback is now known as canuck
08:22 PM Rab: CaptHindsight[m], not a surprise for those cheapies.
08:22 PM canuck is now known as flyback
08:23 PM CaptHindsight[m]: I'll debug my input only ch382 one of these days
08:23 PM Rab: CaptHindsight[m], still leaning toward grey primer...it's not a critical application. I might forgoe the self-etching stuff.
08:24 PM CaptHindsight[m]: epoxy primer replaced self etch
08:24 PM CaptHindsight[m]: both are for direct to metal
08:24 PM Rab: It's just a frame to mount a small machine in a rack, once installed it shouldn't be subject to abuse.
08:26 PM roycroft: no, but it's really tight
08:26 PM roycroft: i could possibly install an intermediate shaft, but that would be a big hassle
08:26 PM CaptHindsight[m]: i get 2 gal (1 gal of base + 1 gal cure) epoxy primer for $120
08:27 PM CaptHindsight[m]: 2 qt kit is like $80
08:28 PM CaptHindsight[m]: or $60
08:29 PM roycroft: it sounds like nobody is suggesting that my notion that a vfd would not perform well at such a low frequency is incorrect
08:31 PM CaptHindsight[m]: I don't have all the info from you yet
08:31 PM CaptHindsight[m]: need to know what you have, and how much room there is
08:31 PM CaptHindsight[m]: the numbers are academic
08:31 PM roycroft: i describd the pulley sizes already
08:32 PM roycroft: the cabinet that contains the motor is pretty full of motor, and the current motor is 1.5hp single phase
08:32 PM roycroft: i can go down to 1hp for the motor
08:32 PM roycroft: but not any less powerful than that
08:33 PM CaptHindsight[m]: 1hp at ~130 rpm
08:33 PM roycroft: and i said already that an intermediate shaft might be doable, but it would be a tight fit
08:33 PM CaptHindsight[m]: 750w , 130 rpm
08:34 PM roycroft: i don't see motors that are that slow
08:34 PM roycroft: but i've been looking at 3 phase motors
08:34 PM roycroft: and 1200rpm is as slow as they commonly go
08:34 PM roycroft: i could do fixed speed
08:34 PM CaptHindsight[m]: 14in to 2 in is 7:1 reduction and you need 13:1
08:35 PM roycroft: i cannot drive the 14" wheel directly
08:35 PM roycroft: it's on a shaft with a 6" pulley, which is what i drive with the motor
08:35 PM CaptHindsight[m]: grooved pulley for a belt?
08:35 PM roycroft: that pulley could be as large as 8"
08:35 PM roycroft: yes
08:35 PM roycroft: but i can use whatevr
08:35 PM roycroft: whatever
08:36 PM roycroft: i'll need a new belt anyway
08:36 PM roycroft: but it's a v-groove pulley
08:36 PM CaptHindsight[m]: I though one pulley is 14 in and the other is a 3in
08:36 PM roycroft: no
08:36 PM roycroft: the motor pulley is 3"
08:36 PM roycroft: it drives a 6" pulley
08:36 PM roycroft: that pulley is on the same shaft as the 14" wheel that drives the sawblade
08:37 PM CaptHindsight[m]: 14:6:3 right now?
08:37 PM roycroft: yes
08:41 PM CaptHindsight[m]: 14:6:3 with 1720 rpm motor = 3300 sfm, is this what you have now?
08:41 PM CaptHindsight[m]: and you want to get down to 250 sfm?
08:42 PM CaptHindsight[m]: another ~13:1
08:43 PM roycroft: yes and yes
08:44 PM roycroft: and i can get part way there with a 1200rpm motor and changing the 6" pulley to an 8" pulley
08:44 PM roycroft: my question is if a vfd would handle the rest of the reduction
08:45 PM roycroft: my experience is that running a vfd below about 30-35% of the motor's rated frequency results in either significant loss of torque or stalling
08:45 PM CaptHindsight[m]: 14:8:3 with 1200 rpm motor
08:45 PM roycroft: but my vfd experience is mostly with inexpensive imported vfds that are not from europe
08:45 PM roycroft: here's the bottom line:
08:46 PM roycroft: i have an old wood bandsaw that i could realistically sell for about $400
08:46 PM roycroft: i'd like a dedicated vertical metal bandsaw
08:46 PM roycroft: that costs about $4k
08:46 PM roycroft: although that price included a blade welder, which is nice
08:46 PM roycroft: i don't want to spend $40
08:46 PM roycroft: $4k, rather
08:47 PM roycroft: but i would be willing to invest a few hundred dollars making the machine i have slow down so it can cut steel
08:47 PM roycroft: if i bought a $400 motor and a $200 vfd i'd have $1k into it, including the resale value of the machine as it sits
08:48 PM roycroft: and i'd have a spare 1.5hp single phase motor to use for something else, which is worth at least $150
08:48 PM roycroft: so i'd probably do that
08:49 PM roycroft: if a vfd won't work, i'd consider other options
08:49 PM roycroft: a slow speed dc motor might do
08:54 PM CaptHindsight[m]: https://www.blocklayer.com/pulley-belteng
08:54 PM XXCoder: capt did you see my earlier comment? quite a while ago
09:00 PM CaptHindsight[m]: XXCoder: sorry, nope
09:00 PM XXCoder: its fine.
09:00 PM CaptHindsight[m]: Multiple Pulley Sets - RPM Reduction @ https://www.blocklayer.com/pulley-belteng
09:00 PM XXCoder: basically guy at that slsforall suggested other to buy formlabs sls powder pa11
09:00 PM XXCoder: 118 usd ouch
09:00 PM XXCoder: and 10 lb a time too
09:01 PM XXCoder: 1180 is a lot of money lol
09:01 PM CaptHindsight[m]: formlabs sls powder
09:01 PM CaptHindsight[m]: XXCoder: yup
09:02 PM CaptHindsight[m]: I'm bust right now so I', not following that project much
09:02 PM XXCoder: they have massive not invented here problem
09:02 PM CaptHindsight[m]: no big deal I can put up changes and parts lists whenever
09:02 PM XXCoder: they will end with workable product but it wont be best possible, and locked to very expensive stuff
09:03 PM CaptHindsight[m]: and people are all ready contacting me directly
09:03 PM XXCoder: for sls powder and machine design?
09:03 PM CaptHindsight[m]: nah, I don't trust a project as open until they share
09:04 PM roycroft: i'm not asking how to calculate the motor speed i need
09:04 PM XXCoder: I meant, are they contacting you for your sls powder or your own sls machine design>?
09:04 PM roycroft: i'm asking about ways to run a motor at the speed i calculate
09:04 PM CaptHindsight[m]: XXCoder: https://www.b9c.com/ this A-hole started a yahoo group and collected howto for about a year or two, then patented, closed it and laughed
09:06 PM XXCoder: wow they use really tiny font and horrible color scheme at forum lol
09:06 PM CaptHindsight[m]: XXCoder: almost everything, some just nosy, some want powders, some ask about parts
09:06 PM XXCoder: interesting
09:07 PM XXCoder: well if I ever build sls machine (yeah right) id want to do nylon and ti metal as minium
09:07 PM XXCoder: sls4all wont do metals. or any plastic not black
09:07 PM XXCoder: like you said
09:07 PM XXCoder: so I doubt I would build that one
09:07 PM CaptHindsight[m]: roycroft: yeah you can run your ratios and check the power required
09:08 PM CloudEvil: Can you SLS PTFE if you don't care about emissions?
09:08 PM solarwind: Hey guys, how do I remove a snap ring that looks exactly like this? https://cdn.rona.ca/images/63867393_L.jpg
09:09 PM solarwind: Without scratching up the shaft with pliers and sucyh
09:09 PM solarwind: It doesn't have holes where you'd normally insert snap ring pliers
09:10 PM CaptHindsight[m]: CloudEvil: any thermoplastic
09:11 PM CaptHindsight[m]: CloudEvil: https://www.cdiproducts.com/blog/ptfe-the-wonder-thermoplastic
09:11 PM CloudEvil: I have been recently wondering about low temperature sintering of copper/ptfe/tin.
09:11 PM CaptHindsight[m]: "PTFE is processed by cold shaping followed by heat treatment (also known as sintering), which causes the polymer particles to fuse together to produce a solid molding."
09:12 PM CloudEvil: To make a bronze matrix PTFE loaded sponge.
09:12 PM solarwind: Never mind, I just pulled on the back side
09:12 PM CaptHindsight[m]: CloudEvil: pry on either of Mickeys ears
09:12 PM CaptHindsight[m]: solarwind: sorry
09:13 PM solarwind: For some reason I'm spending this evening rebuilding a $10 motor from a fan
09:14 PM solarwind: It's a nice motor, don't want to throw it out
09:14 PM CloudEvil: :)
09:17 PM CaptHindsight[m]: roycroft: if you don't have the power curves of the motors you can only guess or assume the worst case
09:24 PM CaptHindsight[m]: CloudEvil: depends on the shape and how much ptfe and coper
09:50 PM Teophanea[m] is now known as Teophanea7482[m]