#linuxcnc Logs

Sep 03 2020

#linuxcnc Calendar

12:58 AM Deejay: moin
02:49 AM Valen: What's the go with linuxcnc and mesa brushless these days? Plug and play?
02:55 AM Valen: Loetmichel: 2 suggestions for your story you have a typo in "turned it around [ad] rammed" and the "What the?" felt too human colloquial for the aliens tone of voice. Other than that nice story man ;-)
02:56 AM Valen: oh have you seen the "dust" youtube channel? Lots of sci-fi shorts there that all seem to be really well made
05:14 AM JT-Cave: morning
05:14 AM XXCoder: yo
06:14 AM Tom_L: morning
06:20 AM JT-Cave: morning
06:30 AM XXCoder: morning
07:33 AM Loetmichel: Valen: thanks, will correct that. and thanks for the kind words for a first writing ;)
09:42 AM beachbumpete1: Morning
09:43 AM gp5st: I'm sorry; I know this is a really stupid question. Say I wanted to build a CNC lathe. How does one write g-code (or get a cam) to make the z-position dependent on the spindle's angular position?
09:43 AM gp5st: g'morning beachbumpete1
09:45 AM skunkworks: gp5st: some is built in - like threading and tapping
09:45 AM skunkworks: what are you trying to do?
09:47 AM gp5st: skunkworks, well, right now just day dreaming :( but I was thinking of trying a lathe build and something I would love to be able to make is a level winding screw
09:52 AM gp5st: oh, I see. There are g-codes for thread cutting
09:53 AM skunkworks: well - you can string spindle synced motions together to create shapes but I don't know how you might do that...
09:56 AM gp5st: the couple videos on youtube usually have a rotary tool in the toolholder while spinning the main spindle slowly and then it cuts a left and right thread afaict
10:00 AM skunkworks: sure - that is using the spindle as an axis.
10:00 AM skunkworks: I think you could also cut it like 'threads' but it might take some thought.
10:02 AM skunkworks: gp5st: this is using stringed together g33 commands https://www.youtube.com/watch?v=ACvRilmIKDQ
10:02 AM gp5st: oh. http://linuxcnc.org/docs/html/examples/spindle.html http://wiki.linuxcnc.org/cgi-bin/wiki.pl?SpindleSynchronizedMotion
10:03 AM skunkworks: pretty convoluted program - but he is a very smart person.. ;)
10:03 AM skunkworks: http://wiki.linuxcnc.org/cgi-bin/wiki.pl?JMKsFusee
10:04 AM gp5st: skunkworks, i'm like a level -1 machinist :( I think the issue with thread cutting it is that it requires clean ends to the thread (without a cutter or overrun) to allow the follower of the level-winding screw to not snag/get stuck?
10:04 AM skunkworks: or this is also more like maybe what you are thinking of..
10:04 AM skunkworks: https://www.youtube.com/watch?v=zdCQ0X7b2uo
10:05 AM skunkworks: also g33
10:05 AM roycroft: knurling is a forming operation, not a cutting operation
10:05 AM roycroft: that video is a lie :)
10:06 AM skunkworks: instead of the stopping at the right - you would be running the same path back again..
10:06 AM skunkworks: (he is offseting so in effect he has multible leads)
10:07 AM skunkworks: roycroft: whatever to get the job done. (or show off)
10:07 AM gp5st: I was thinking more threadmilling style https://www.youtube.com/watch?v=6_1Nlf-X4bw (in general) https://www.youtube.com/watch?v=v68WRtSdFGc (short video of a level winding screw being cut)
10:07 AM roycroft: i'm not saying that's not a valid operation
10:08 AM roycroft: i'm saying it's not knurling
10:08 AM gp5st: interesting. you could hob if both axes could be well controlled
10:09 AM skunkworks: umm... Glad you asked...
10:09 AM skunkworks: ;)
10:10 AM skunkworks: https://www.youtube.com/watch?v=ZhICrb0Tbn4
10:11 AM gp5st: Why do people build cnc mills? ;) CNC lathes seem much cooler. (Well, lathes seem much cooler than mills to start, so...)
10:11 AM skunkworks: or something a bit more obscure...
10:11 AM skunkworks: https://www.youtube.com/watch?v=wv7mMS5xKks
10:12 AM * skunkworks is mostly team mill.
10:12 AM roycroft: lathes and mills are not alternatives
10:12 AM roycroft: they are complementary
10:13 AM skunkworks: or
10:13 AM skunkworks: https://www.youtube.com/watch?v=c9tWtEG1Exc
10:17 AM Rab: I was turning stainless on my mill yesterday. (5/16" stock in a collet...)
10:18 AM Rab: But buying the mill prODODODODODODODODODODODODODODODODODODODetty quickly made me eager to buy a lathe.
10:18 AM Rab: what the
10:18 AM skunkworks: heh cat?
10:19 AM skunkworks: while typeing?
10:19 AM Rab: No, lagged while backspacing. I've never seen that before.
10:22 AM Rab: Not many lathes to be had, here. A local school has an Emco PC Turn 55 up for auction, which might go for cheap, but it's kind of a toy...not a whole lot more than an automated Unimat.
10:24 AM gp5st: roycroft, yes, they are :)
10:29 AM gp5st: thanks for those videos skunkworks
10:29 AM skunkworks: sky is the limit with linuxcnc..
10:30 AM gp5st: well, my wife's tolerance of my spending is the limit ;)
10:31 AM gp5st: roycroft, what would be the proper term "cutting knurls"
10:39 AM Rab: Knurl milling!
11:21 AM andypugh: gp5st: FWIW every one of those videos is from someone who is online here now.
11:22 AM andypugh: (Ooops! not Justin Fontes, just saw that one.
11:22 AM andypugh: Where can I find a 0.085” spanner?
11:23 AM andypugh: (I think the answer is “inside a piece of metal in the workshop”)
11:59 AM Tom_L: andypugh, :) exactly
12:07 PM gp5st: andypugh, oh cool!
12:09 PM gp5st: I don't have any setup right now. I'm trying to figure out if I have enough time to even make use of it if I spent the money on it
12:09 PM gp5st: or what I would use it for other than making more tools
12:11 PM gp5st: not that that's bad; it's just not a good sell to the wife :D
12:28 PM beachbumpete1: Just tell her that chicks dig metal swarf in the carpet man. She'll help you whip out that credit card quick. ;)
12:29 PM jymmmm: hello
12:29 PM Tom_L: beachbumpete1, is that how you got your lathe?
12:34 PM beachbumpete1: hell yeah man doesn't everybody do it that way?
12:35 PM beachbumpete1: actually when I first got my 12x36 we were renting a house
12:35 PM beachbumpete1: I put my mill and lathe in a spare bedroom
12:35 PM beachbumpete1: I bought 3/4 inch plywood and some thick visqueen
12:35 PM beachbumpete1: i lined the entire floor and taped the visqueen like a foot up the wall
12:35 PM beachbumpete1: then laid the plywood down covering the entire floor
12:36 PM beachbumpete1: then brought in the machines
12:36 PM beachbumpete1: lived in that house for like 8 years
12:36 PM Tom_L: heh
12:36 PM beachbumpete1: made tons of parts in the room.
12:36 PM beachbumpete1: the only problem was the chips that got OUT of the room LOL
12:36 PM beachbumpete1: when we moved that bedrooms carpet looked brand damn new
12:36 PM beachbumpete1: and the rest of the house did not hehehe
12:38 PM Tom_L: ever get anything done on the lathe yet?
12:38 PM beachbumpete1: I KNEW you were gonna ask me that
12:38 PM Tom_L: well of course!
12:38 PM FinboySlick: gp5st: Don't underestimate the need for a proper floor for a good mill.
12:38 PM beachbumpete1: honestly man I have not done jack shit with the lathe
12:39 PM beachbumpete1: I have been learning to play guitar
12:39 PM FinboySlick: beachbumpete1: You've been latheless too long, you lost it, man.
12:39 PM beachbumpete1: and spend most evenings that I do not have work to do on the mill sittin on the couch trying to learn new licks
12:39 PM beachbumpete1: hell yeah I have
12:39 PM beachbumpete1: Ive gone fuckin boners
12:39 PM Tom_L: ok so since you did diddly squat with the lathe, did you ever build that guitar???
12:39 PM beachbumpete1: bonkers
12:40 PM beachbumpete1: I have been working on the guitar actually
12:40 PM Tom_L: +1 for beachbumpete1
12:40 PM beachbumpete1: I tried some purple stain that someone receommended
12:40 PM beachbumpete1: and it looks like shit
12:40 PM Tom_L: heh
12:40 PM beachbumpete1: so I am gonna have to sand it all down
12:41 PM Tom_L: you may have to sand a long ways if that soaked in
12:41 PM beachbumpete1: that and I should have used a black dye before it to make the grain pop and I did not
12:41 PM beachbumpete1: well its gonna be purple so its all good
12:41 PM beachbumpete1: but its just not the right purple right now
12:41 PM Tom_L: gotta run for a bit
12:41 PM beachbumpete1: cya
12:41 PM beachbumpete1: I need a lathe man
12:42 PM FinboySlick: beachbumpete1: Lack of coma is ambiguous. You need a real man capable of operating your lathe?
12:43 PM FinboySlick: A 'lathe man', as it were.
12:43 PM beachbumpete1: hell man if you had any idea how many hours I stood in front of a manual lathe.....
12:44 PM FinboySlick: 'cause Adam Booth isn't too far from you.
12:45 PM beachbumpete1: who?
12:46 PM FinboySlick: https://www.youtube.com/watch?v=SMhbRPqwfa0
12:46 PM skunkworks: abom?
12:46 PM FinboySlick: Yeah.
12:48 PM beachbumpete1: oh yeah? thought he was a midwesterner
12:49 PM FinboySlick: I think you're actually in the same town.
12:55 PM FinboySlick: Pensacola if I recall.
12:56 PM FinboySlick: (not sure where you are, that's where he is)
01:48 PM * JT-Shop just found a library to read tag values from a CompacLogix PLC!!!
03:00 PM jymmmm: Loetmichel: Any suggestons for magnetic field shielding?
03:07 PM Deejay: gn8
03:22 PM FinboySlick: beachbumpete1: It's all the same to a Canadian ;)
03:23 PM FinboySlick: You're in the warm place with hurricanes.
03:46 PM roycroft: canada will be a warm place with hurricanes before too long
03:47 PM roycroft: so don't get too lumpy about things :)
03:52 PM robotustra: < roycroft> canada will be a warm place with hurricanes before too long
03:52 PM robotustra: tell me when? :)
03:52 PM robotustra: it's winter and cold soon
04:33 PM zipper is now known as Guest49711
04:46 PM * JT-Shop calls it a day...
04:47 PM Tom_L: a Thurs day?
04:47 PM Tom_L: finally got the spi lib figured out ehh?
04:48 PM JT-Shop: yea the spi I'm just using spidev and have my own routine
04:48 PM JT-Shop: it's rather simple once you understand what it needs
04:49 PM JT-Shop: one caveat is you have to send a long enough tail string so each led has time to read the string and pass the remainder along
04:49 PM Tom_L: sounds alot like everything else :)
04:49 PM JT-Shop: because the clock is not interrupted by the led only the data line
04:50 PM Tom_L: slow data rate?
04:50 PM JT-Shop: each led reads the date in turn, first one gets its data replaces it with 0's and on the falling edge sends it to the next one
04:51 PM JT-Shop: so each led takes 1/2 clock cycle to process the data
04:52 PM JT-Shop: no, the clock can be fast
04:52 PM JT-Shop: it just eats 1/2 clock for each led
04:52 PM JT-Shop: so you need to clock to keep ticking until the last led has read it's data
04:53 PM JT-Shop: new fun is to read tags from a CompacLogix PLC with a Rpi
04:54 PM JT-Shop: lucky there is a lib and the author is on plcs.net
04:54 PM JT-Shop: err plctalk.net
04:55 PM JT-Shop: got the basic frame for the hopper on the spoke lathe tacked together today
05:04 PM roycroft: i'm going to fit my tail vise today
05:04 PM roycroft: and it's going to make a huge mess, so i think i'll set up some saw horses outside to do that
05:31 PM JT-Shop: I'm thinking of a modified Moravian workbench 24" x 48"
05:32 PM robotustra: https://www.youtube.com/watch?v=jVcn2yQReDI
05:33 PM roycroft: a moravian bench would be nice
05:33 PM JT-Shop: no tool tray but bigger work surface
05:33 PM JT-Shop: what is the split bench for?
05:34 PM roycroft: while i'm not recommending the benchcrafted vise hardware for you, they've tested their leg vise hardware on angled legs, and found that it works at 15 degrees or less
05:34 PM roycroft: three things:
05:34 PM roycroft: 1. with the split opened up i can fit clamps in it so i can clamp from the middle as well as the edges
05:34 PM roycroft: 2. a tool well can be fit in it to hold tools while working
05:35 PM roycroft: 3. the tool well can be flipped upside down so that it protrudes from the bench top a bit and can be used as a planing stop
05:35 PM JT-Shop: I saw 3 and that seemed like a good idea
05:35 PM JT-Shop: didn't think about 1 which is also good to have
05:35 PM roycroft: for 2, i'm not talking about a tray
05:36 PM roycroft: basically it's two boards with spacers, so it's mostly open
05:36 PM roycroft: easy to stuff chisels and the like in it
05:36 PM roycroft: but the ability to clamp in the middle is the biggest reason for me
05:36 PM JT-Shop: notches on the one side let it sit flush?
05:37 PM roycroft: yes
05:37 PM roycroft: so it can live in the bench most of the time
05:37 PM JT-Shop: makes sense
05:37 PM JT-Shop: I'm thinking I'll make a wagon wheel end vise
05:37 PM roycroft: yes, you want a wagon vise for sure
05:37 PM roycroft: you really do
05:38 PM JT-Shop: seems easy enough to make if you have a machine shop
05:38 PM roycroft: yes
05:38 PM roycroft: i bought mine
05:38 PM roycroft: and paid a lot for it
05:38 PM roycroft: but most of the money was for the screw
05:38 PM roycroft: it's a double thread acme screw, highly polished
05:38 PM JT-Shop: left hand thread?
05:38 PM roycroft: yes
05:38 PM JT-Shop: makes sense
05:39 PM roycroft: i really like the benchcrafted handwheels too
05:39 PM roycroft: they look awesome, and are really comfortable
05:39 PM roycroft: i need to get mine ready soon
05:39 PM JT-Shop: does the benchcraft have a thrust bearing?
05:39 PM roycroft: i made a moxon vise with their hardware, and i cold blued the handwheel, then heated it up and put gun oil onit
05:40 PM roycroft: handwheels, i should say
05:40 PM JT-Shop: nice
05:40 PM roycroft: the tail vise does have a thrust bearing
05:40 PM roycroft: well, a thrust washer
05:40 PM roycroft: and it's not a tight fit
05:40 PM roycroft: but it doesn't need to be
05:41 PM JT-Shop: I have some heavy duty linear rails lol I might use
05:41 PM roycroft: https://www.benchcrafted.com/download-files/Tail-Vise_Instructions-BC0319.pdf
05:41 PM roycroft: their installation instructions
05:41 PM JT-Shop: gotta get this 1800's spoke lathe automation project done so I can build
05:42 PM roycroft: which includes diagrams of the parts
05:42 PM JT-Shop: I watched the video this morning
05:43 PM roycroft: a traditional tail vise, like the scandanavian design, will sag over time
05:43 PM roycroft: a wagon vise should stay nice and tight indefinitely
05:43 PM roycroft: and the benchcrafted one uses 5/16" steel - pretty heavy duty for what it is
05:44 PM roycroft: anyway, i have a *lot* of wood to hog out right now with a router
05:44 PM roycroft: so i should go get started
05:44 PM roycroft: time to make a mess!
05:44 PM JT-Shop: ok
05:45 PM roycroft: the moravian is a good design, especially for a first bench
05:45 PM roycroft: the angled legs let you make it really sturdy without being overly massive
05:45 PM JT-Shop: that's what I was thinking
05:45 PM JT-Shop: I'll not make it a knock down
08:44 PM XXCoder: gear porn https://youtu.be/mkQ2pXkYjRM
08:47 PM Rab: It is weirdly erotic.
08:52 PM Rab: The last third is really trippy.
08:52 PM Rab: Many of the gears look cast, to me.
08:52 PM XXCoder: spirl ones?
08:52 PM XXCoder: yeah thats norm back then
08:53 PM Rab: Yeah: nautilus gears, square gears, gears driving each other, varying pitch, etc etc.
08:54 PM XXCoder: its good for varying speed
08:54 PM XXCoder: i wonder if those is even in use nowdays
08:54 PM Tom_L: i downloaded a book with alot of those mechanisms
08:54 PM XXCoder: theres site for it too
08:54 PM Rab: There was someone who obsessively posted like a hundred modeled linkages to YouTube, each in its own little video. Great stuff.
10:09 PM roycroft: well that was huge
10:09 PM roycroft: i got my tail vise fitted to the bench top today
10:09 PM roycroft: and it fits perfectly
10:10 PM roycroft: i'm taking the slow, steady, careful approach to this build, and it's been working out well