#linuxcnc Logs
Apr 12 2023
#linuxcnc Calendar
12:41 AM -!- #linuxcnc mode set to +v by ChanServ
01:15 AM Deejay: moin
01:18 AM rmu: mrec: my point was that they can't even get the title correct ;)
01:24 AM randy: morning
02:45 AM -!- #linuxcnc mode set to +v by ChanServ
02:51 AM -!- #linuxcnc mode set to +v by ChanServ
04:39 AM Tom_L: morning
05:06 AM JT-Cave: morning
07:34 AM travis_farmer[m]: Morning 🙂
07:36 AM TurBoss: morning!
09:31 AM skunkworks[m]: huh - why can't I reply to April 2023 LinuxCNC meeting at Tormach headquarters
09:32 AM skunkworks[m]: on the forums
09:36 AM gpunk: i got me a CNC3018, i didnt know the MB would be from vigotec
10:52 AM * JT[m] uploaded an image: (291KiB) < https://libera.ems.host/_matrix/media/v3/download/matrix.org/RYZMuncNDBsNwLYVIBmxuadY/20230412_085632.jpg >
10:52 AM JT[m]: Last pattern ring glued on
10:54 AM Rab: wow
10:55 AM roguish[m]: JT: pretty darn nice JT
11:07 AM JT[m]: Thanks, can't wait to start shaping it
11:08 AM JT[m]: Still gotta make the top ring of wenge
11:10 AM roycroft: have you turned wenge before?
11:16 AM JT[m]: No, well yes the base is wenge
11:17 AM Deejay: impressive!
11:20 AM * JT[m] uploaded an image: (357KiB) < https://libera.ems.host/_matrix/media/v3/download/matrix.org/NnoVkhfzUZpWhfbMcaDUGIqB/20230226_121920.jpg >
11:20 AM JT[m]: The practice bowl
11:24 AM roycroft: make sure your tools are sharp and you use a light touch
11:25 AM roycroft: wenge, in my experience, can be pretty grabby
11:25 AM JT[m]: Where I'm having issues with tear out is the end grains
11:26 AM JT[m]: Zoom in on the current bowl and you can see the tear out
11:33 AM roycroft: yeah, i tried using wenge as a faux ebony for some plugs, but it didn't work out well
11:34 AM roycroft: i was able to dye it with india ink and the color was right, but the end grain was kind of rough and i couldn't polish it up like ebony
11:38 AM JT[m]: Yup wenge has some soft grain mixed in
01:09 PM * JT[m] uploaded an image: (327KiB) < https://libera.ems.host/_matrix/media/v3/download/matrix.org/rHowFncTKevdrjjDuHVifdLS/20230412_130830.jpg >
01:18 PM Tom_L: yum
01:19 PM Tom_L: better than what i just had
01:19 PM Rab: This LinuxCNC-urelated content is nevertheless highly relevant to my interests.
01:22 PM JT[m]: A little dive near Cape Girardeau
01:38 PM * JT[m] uploaded an image: (289KiB) < https://libera.ems.host/_matrix/media/v3/download/matrix.org/UnIvOwmceilRBFNjhnzahyyb/20230412_133647.jpg >
01:46 PM roguish[m]: JT: jeeeze, you're drinking that dog piss beer.....
01:48 PM bjorkintosh: roguish[m], as opposed to PBR? :-))
01:48 PM roguish[m]: or Buttwipers
01:49 PM roguish[m]: Busch or Miller
01:50 PM bjorkintosh: damn. I normally drink water.
01:50 PM bjorkintosh: where does that put me on the canoe scale?
01:51 PM roycroft: i think we're boycotting anheuser-busch these days because they made a video that some freedom-loving people don't like
01:53 PM bjorkintosh: oh we are?
01:53 PM bjorkintosh: maybe next time.
01:56 PM roycroft: allegedly
01:57 PM roycroft: i'm not sure i'm boycotting them
01:57 PM roycroft: i don't consume any of their product already
01:58 PM roycroft: so it would seem disengenuous to claim i'm "boycotting" something that i've never actively engaged with
02:03 PM -!- #linuxcnc mode set to +v by ChanServ
02:23 PM XXCoder: lol https://www.youtube.com/watch?v=hKyNqc1p2iw
02:29 PM bjorkintosh: madness.
02:30 PM bjorkintosh: so clever.
02:36 PM roycroft: it's a canadian bicycle!
02:37 PM XXCoder: canadian?
02:38 PM Unterhaus_: it's a Canadian bicycle hey?
02:40 PM roycroft: https://www.youtube.com/watch?v=jt4TjhPdyW8
02:41 PM XXCoder: ahh lol
02:50 PM roycroft: australians say hey?
02:50 PM roycroft: canadians say eh?
03:26 PM JT-Shop: there was about 12 new hondas on the dealers lot today... the rest were used cars
03:29 PM JT-Shop: roguish[m], they were out of Weihenstephaner
03:30 PM JT-Shop: I should have asked for a Stag
03:58 PM roguish[m]: JT-Shop: just funnin ya. I usually ask for a local brewery beer, just to support local business......
03:58 PM roguish[m]: I did go night club dancing once upon a time with a gal named Susie Busch. her father owned a baseball team and more.....
04:01 PM bjorkintosh: roguish[m], she wasn't a machinist, I take it?
04:04 PM roycroft: it was probably a busch league team
04:07 PM roguish[m]: she was very nice, and pretty, but ya could tell she was a rich girl. didn't matter. fun to drink and dance with.... never saw her again. probably went home to the mid-west......
04:31 PM Tom_L: JT-Shop hangs out in some pretty questionable establishments... bars on the windows.. hope he's never been booted
04:32 PM JT-Shop: lol
04:33 PM roycroft: i bet he's even been to an establishment that has both kinds of music - country and western
04:34 PM * JT-Shop goes to make some chicken crack
05:14 PM _unreal_: shhhh
05:18 PM _unreal_: nothing going on tonight?
05:24 PM roycroft: it's sushi night
05:24 PM roycroft: so good food and good times with friends will be going on soon
05:35 PM JT-Shop: my deceased business partners daughter sent me a friend request on fb and I confirmed now I have a bunch of friend requests from people I don't know
05:38 PM roycroft: sounds like her account has been compromised
05:41 PM JT-Shop: I think it's her friends they all look the same age 20ish
05:42 PM JT-Shop: I just looked and all three are from other mutual friends and none from her
05:43 PM JT-Shop: did I mention I hate fb
05:48 PM roguish[m]: JT-Shop: ya don't gotta accept the friend requests ............ as an older white guy, be very careful.....our kind are the scourge of the earth these days.
05:48 PM JT-Shop: lol
05:49 PM JT-Shop: I really don't care :)
05:50 PM JT-Shop: I only accept friend requests from close friends
05:54 PM roguish[m]: there ya go. a wise old guy. full of sagacity
05:55 PM JT-Shop: I actually only use fb marketplace
05:55 PM XXCoder: yeah seen quite a lot "friend hoarder"
05:55 PM XXCoder: hundreds of friends and guy dont know most of em
05:58 PM roguish[m]: I just stay in touch with friends around the country and world...
05:59 PM JT-Shop: I need to find a can of johnsons paste wax
06:00 PM roguish[m]: little dab will do ya...
06:01 PM JT-Shop: I can't find any locally
06:13 PM Tom_L: amazon will fix you right up
06:14 PM JT-Shop: I've not found any on amazon
06:14 PM JT-Shop: https://www.amazon.com/SC-Johnson-Paste-Wax-1lb/dp/B0000DIWIM
06:15 PM JT-Shop: https://www.ebay.com/itm/145008142207?chn=ps&mkevt=1&mkcid=28&srsltid=AfAwrE4eWIB8FI0ZX9zzYwh321yHoiUd4OcM2J4KDZyxAydqqeCdiqmaMbk
06:17 PM ve7it: no better in Canada!.... https://www.amazon.ca/SC-Johnson-00203-Wood-Paste/dp/B0000DIWIM/ref=sr_1_1?crid=2QH0TV6EW6VL3&keywords=SC+Johnson+Paste+Wax&qid=1681341332&sprefix=sc+johnson+paste+wax%2Caps%2C165&sr=8-1
06:17 PM JT-Shop: wow
06:18 PM ve7it: time to mix up some counterfeit sauce
06:19 PM ve7it: beeswax, old candles, used crankcase oil... a little heat.... what could go wrong?
06:20 PM ve7it: weird stuff just seems to be going away...
06:20 PM Tom_L: s/weird/good
06:21 PM JT-Shop: so if anyone finds a can in an old parts store or hardware store grab it for me
06:22 PM ve7it: I have actually been looking for a can of paste wax here for a few years... would like some for the table saw
06:22 PM JT-Shop: for all my machine tables...
06:22 PM Tom_L: 3m makes some
06:22 PM ve7it: closest thing I have found is some of the Mothers waxes in the automotive department
06:23 PM Tom_L: https://www.napaonline.com/en/p/MMM39526?impressionRank=3
06:25 PM JT-Shop: I'll look at napa to see if they have any
06:28 PM Tom_L: if any auto place would they would be the likely one
06:29 PM roycroft: i like rennaisance wax for larger objects
06:29 PM roycroft: it's kind of expensive, but it works a charm, and you can rub it in and wipe it off immediately
06:29 PM roycroft: no waiting for it to dry
06:30 PM * roycroft just discovered that cutting leather with his laser engraver/cutter may be rather challenging
06:31 PM roycroft: when it cuts through to the back of the leather, little bits of the leather come up, and get pretty glowy from the laser, which triggers the flame alarm and shuts it down
06:31 PM JT-Shop: you use rennaisance wax on table saws etc?
06:31 PM roycroft: oh, no
06:31 PM roycroft: i use boeshield t-9 on my machine tables
06:32 PM roycroft: it works better than anything i've ever tried
06:32 PM roycroft: if you get some, don't get the spray can, though
06:32 PM JT-Shop: I have a spray can... and the bike one
06:32 PM roycroft: it's too expensive, and the nozzle usually clogs before you use it all up, making it even more expensive
06:32 PM roycroft: get the squirt bottle for bicycle chains
06:32 PM JT-Shop: I like to wax the tables to make them slicker
06:32 PM roycroft: it's the exact same stuff, but cheaper
06:33 PM roycroft: i find that boeshield works pretty well, but i keep a bar of carnauba wax with me and rub a little of that on tables that get sticky
06:33 PM roycroft: primarily my jointer and my bandsaw
06:34 PM roycroft: i also use it on the soles of my handplanes
06:34 PM roycroft: https://www.amazon.com/dp/B0B325BYY7
06:35 PM roycroft: there's a five year supply
06:35 PM JT-Shop: https://www.amazon.com/PremiumCraft-100-Carnauba-Wax-Bar/dp/B00OVNUSVI
06:35 PM roycroft: unless you start using it on your turned bowls
06:38 PM * roycroft heads off for sushi
06:54 PM XXCoder: heyy get me some
07:10 PM bjorkintosh: Oh Japan. Never change! https://www.youtube.com/watch?v=bPTSSHRnnWw
07:12 PM XXCoder: that thing is amazing
07:19 PM bjorkintosh: the motors are tiny.
07:19 PM bjorkintosh: I expected something much much bigger.
08:30 PM mrec: does anyone roughly know how the hostmot2 stepgen operates? eg. how is acceleration and deceleration handled?
08:31 PM Tom_L: pcw does
08:37 PM pcw-home: The stepgen itself does not handle acceleration and deccelration that's up to the TP
08:37 PM mrec: TP?
08:37 PM pcw-home: Trajectory Planner (though the driver can bound these)
08:39 PM mrec: ah ok. so how is the acceleration handled with stepgen if the TP takes care about it?
08:39 PM pcw-home: The TP has acceleration limits
08:41 PM mrec: does it tell stepgen start here end here with those acceleration / deceleration values? but you said that the TP takes care about that so what is happening during the acceleration stage?
08:42 PM pcw-home: No, the TP simple provides position waypoints that do not violate acceleration or velocity constraints
08:42 PM mrec: I'm working on a pick and place machine, currently I use the STM32F4 for generating the steps (at around 350khz). The limitation seems to be the JMC IHSV57 controller so far (pulse length, pulse spacing)
08:43 PM mrec: strip that 350khz it's lower.
08:46 PM pcw-home: 350 KHz would be about 1.4 usec high/low which is fast for cheap drives
08:47 PM mrec: ya I'm wrong with that it's only around 17-18khz at the moment
08:47 PM mrec: 500 pulses per rev/20mm
08:48 PM pcw-home: Right, I remember from the other day
08:48 PM mrec: I can't go much faster otherwise I'll get various issues also with the powersupply.
08:48 PM mrec: even though I'm using a 350w PSU for the 180w motor it will pass out
08:49 PM pcw-home: I would think PS drooping would be mostly a matter of acceleration
08:49 PM mrec: deceleration is the issue acceleration is fine actually, so something with back-emf
08:50 PM pcw-home: (a 180 w servo may draw ~800 W during accel)
08:50 PM pcw-home: 180W being the continuous power
08:51 PM pcw-home: You may new a clamp (brake) to avoid over-volting the PS during decel
08:51 PM pcw-home: (like VFDs have)
08:52 PM pcw-home: s/new/need/
08:52 PM pcw-home: bbl
08:54 PM mrec: I need another motor .. that one is really budget
09:03 PM mrec: there's no interface for a brake
09:03 PM mrec: brake/resistor
10:13 PM ZincBoy[CAON][m]: A brake circuit is pretty easy to implement separately. You just need a comparator set to a threshold just above your power supply voltage. The comparator drives a fet that switches a resistor across the supply. As soon as the supply exceeds the setpoint the resistor will pull it back down. This just needs to keep the DC bus voltage from exceeding the over voltage protection in the supply.
10:14 PM skunkworks[m]: there are a bunch of circuits people have come up with...
10:14 PM skunkworks[m]: pretty basic
10:14 PM mrec: thanks for the hint
10:17 PM pcw-home: A little bit of hysteresis so you get quick swicting
10:18 PM skunkworks[m]: and for the life of me I can't thik of the common name for themm
10:18 PM skunkworks[m]: them
10:18 PM skunkworks[m]: not snubber.
10:18 PM skunkworks[m]: not crow bar..
10:18 PM pcw-home: a voltage clamp maybe
10:19 PM pcw-home: its not really a shunt regulator as its better to not run in linear mode
10:23 PM skunkworks[m]: I had a bad emc drive and used the supply for it (which had a clamp) for the stmbl drive on my little mill. works great
10:33 PM -!- #linuxcnc mode set to +v by ChanServ
10:35 PM skunkworks[m]: and you can buy them.. I bought a couple and they were huge.. The picture didn't really show scale . 😉
10:37 PM skunkworks[m]: mrec: https://www.cnczone.com/forums/uhu-servo-controllers/67118-regenerative-power-dump-circuit.html
10:40 PM skunkworks[m]: pcw-home: any chance you making it to tormach?
10:56 PM mrec: seems like JMC is giving some support but only in chinese