#linuxcnc Logs

Jul 29 2021

#linuxcnc Calendar

01:43 AM Deejay: moin
02:03 AM randy: morning
06:41 AM -!- #linuxcnc mode set to +v by ChanServ
06:57 AM -!- #linuxcnc mode set to +v by ChanServ
08:22 AM perry_j1987: interesting https://www.youtube.com/watch?v=dnyxpHLtzcQ
08:46 AM perry_j1987: anybody got any interesting projects lined up for the day
08:48 AM enleth: repairing a minisplit unit for the office
08:49 AM roycroft: surviving the heat wave is my project for the day
08:49 AM enleth: I have to turn two brass couplers to solder standard copper tubing onto some weirdo sizes used inside the indoor unit by the factory
08:50 AM CloudEvil: hard solder I assume?
09:00 AM enleth: yep, oxypropane
09:13 AM JT-Cave: hot here already
09:14 AM * JT-Cave has to go to the industrial park and pull sonic weld data sent from a plc to a rpi3... I hope I remember the password
09:34 AM roycroft: we're not looking at a record high, but we'll hit 38 today
09:34 AM roycroft: and that's pretty darn hot
09:42 AM Roguish: hit 99 here yesterday..... supposed to be a bit lower today
09:46 AM perry_j1987: its been tough for the AC in the shop to keep it cool
09:49 AM roycroft: i'm trying to decide what time to turn on the ac in the shop
09:49 AM roycroft: i don't want to waste electricity by turning it on too early, but i don't want it to be unbearably hot when i head out to work there later on today
10:45 AM solarwind: How does this "chill beanie" work? https://canadaweldingsupply.ca/collections/welding-caps/products/blue-demon-arc-chill-beanie
10:46 AM solarwind: So it claims to stay 10º cooler than ambient temperature after soaking it in water of any temperature
10:47 AM solarwind: Same principle as sweating/evaporative cooling?
10:48 AM solarwind: If so, how is it any different than a wet cloth head band?
11:00 AM enleth: possibly more convenient and might be made of a material that soaks in way more water to last longer and/or has a deliberately high surface area to spees up evaporation
11:00 AM enleth: so it might be a highly optimized wet cloth head band
11:00 AM enleth: or just a pointlessly expensive one
12:40 PM solarwind: Is it safe to store micrometers in the fully closed position (but not locked)?
12:41 PM solarwind: Because if I don't, I find that some kind of dust manages to find its way in and I have to clean the faces again very carefully
12:42 PM roycroft: it seems better to leave them open a few thousandths, and i always clean a mic if i need to do a precision measurement anyway
12:47 PM solarwind: roycroft how do you clean it? No matter what I try, some kind of dust always gets in. Should I use alcohol or acetone?
12:48 PM roycroft: i just use a lint-free cloth - like my eyeglass cleaning cloth, and a bit of solvent if there's any gunk on the anvils
12:49 PM solarwind: Gotcha. I think I should have some kimwipes which should be lint-free
12:49 PM roycroft: you might get a pack of eyeglass cleaning cloths - there are small paper ones
12:49 PM roycroft: kimwipes should work
12:50 PM roycroft: all this said, i rarely need precision beyond 0.001", but i try to keep the mic clean anyway
12:50 PM solarwind: Oh you just reminded me I do have a box of small sealed eyeglass cleaning wipes already soaked in isopropanol.
12:51 PM solarwind: That's an interesting thought. I intend to purchase a complete set of micrometers, but some of them don't have a vernier scale for reading tenths. This confused me because I was always led to believe that micrometers were the go-to tool for precision measurements and a thou is actually quite large
12:51 PM roycroft: it's all relative
12:52 PM roycroft: most machinists do not have to hold tenths on most work
12:52 PM roycroft: and there's no point in being more precise than the job requires
12:52 PM roycroft: it's just extra work, extra time, and that translates to lost profit
12:53 PM roycroft: people do not use micrometers because they need to measure tenths
12:53 PM solarwind: Oh wow, looks like I was remembering incorrectly. I was thinking that slip fit vs interference fit was the difference of 5-10µm, but looks like it's actually more like 25µm
12:53 PM roycroft: they use them because they're easy and repeatable
12:53 PM solarwind: That makes sense
12:54 PM solarwind: So a thou reading should be fine for turning shafts for mounting bearings and such then. That's a relief!
12:54 PM -!- #linuxcnc mode set to +v by ChanServ
12:56 PM JT-Shop: I have a set of micrometers for sale that read in tenths
12:57 PM solarwind: JT-Shop I would certainly be interested. Did you list them in an ad anywhere?
12:57 PM JT-Shop: not in a while
12:58 PM solarwind: I'll PM you my email, would it be possible to send me a picture and your asking price?
12:59 PM JT-Shop: yep
01:13 PM JT-Shop: about 6 months after buying them we did a big job and I treated myself to a set of Spi digital micrometers so they were used very little
01:14 PM * JT-Shop goes to mine some chicken dirt before the rains come
01:19 PM solarwind: JT-Shop, sent you my address. Consider them sold
01:22 PM Tom_L: if you want high accuracy micrometers they are available but you will pay
01:23 PM Tom_L: https://www.mitutoyo.com/press_releases/high-accuracy-digimatic-digital-micrometer/
01:23 PM solarwind: Tom_L, yes I have that exact micrometer, but I'm now looking for a set
01:23 PM solarwind: JT just solved my problem
01:23 PM Tom_L: https://www.amazon.com/Mitutoyo-Digital-Micrometer/dp/B00WMLMJH2
01:23 PM Tom_L: that is usually the 'goto' for most shops
01:24 PM solarwind: The Mitutoyos are so beautiful that I'm afraid to take them out of the box
01:24 PM roycroft: i don't have any digital micrometers
01:24 PM solarwind: So I have a cheaper one I "throw around"
01:24 PM Tom_L: that first one, i would probably just look at too and only use in a lab
01:24 PM roycroft: i have an old starrett 0-1", and old craftsman 0-1", and several sizes of no-name imports that are >1"
01:24 PM solarwind: JT's vernier micrometers are exactly what I was looking for so that solves that
01:24 PM enleth: but at that level of accuracy, you must first determine if micrometers in particular are the right tool for the job
01:24 PM roycroft: they all measure tenths
01:25 PM enleth: roycroft: the latter ones might or might not *measure* tenths, all you can say by looking at them is that they're graduated in tenths
01:26 PM roycroft: interesting
01:26 PM roycroft: that mitutoyo is $152.10 on amazon
01:26 PM roycroft: but i was logged into my personal account
01:26 PM roycroft: i switched to my business account and it's $134.50
01:27 PM Tom_L: if it is genuine, it is a good micrometer
01:27 PM roycroft: well, enleth, they do measure tenths
01:27 PM roycroft: but which kind of tenths is debatable
01:27 PM Tom_L: tenths of a mile?
01:28 PM roycroft: if i needed that kind of precision, though, i'd get something a bit higher quality
01:28 PM enleth: Tom_L: by throwing
01:28 PM roycroft: and even then, if i needed super precision i might check the measurement against a stack of gage blocks
01:28 PM roycroft: in a temperature-controlled room
01:29 PM Tom_L: those are plenty accurate for any woodworking project even you would take on :)
01:30 PM Tom_L: certified they're 160
01:30 PM enleth: do you know why woodworkers only measure down to 1/8in? because it's hard to cut up your thumb on a table saw into slices any thinner than that
01:31 PM * roycroft measures to thosandths for some of his woodworking parts
01:32 PM Tom_L: most accidents happen with box cutters because you've waited so damn long for the package you can't wait to get your grubby little hands on it
01:32 PM roycroft: i have a dial indicator attached to a might mag that is stuck on the side of the table saw
01:32 PM roycroft: i use it daily
01:32 PM roycroft: yeah, when the wells fargo wagon only shows up once/month you get pretty excited when it finally arrives
01:33 PM Tom_L: you should fit glass scales to your table saw
01:33 PM roycroft: i do use my finger for fine-tuning most cuts, but not touching the blade
01:33 PM roycroft: the thing about woodworking is that consistency is really important, but absolutely precision not so much
01:35 PM Tom_L: for holes you should be using air gages
01:35 PM roycroft: if i need to cut four pieces of wood 8" long, it doesn't matter if they're 8.015" long or even 8.090" long usually
01:35 PM roycroft: but it does matter that they're all exactly the same length
01:36 PM roycroft: that woodworking does not need to be done accurately because "wood moves" is a bullshit myth perpetuated by lazy, unskilled carpenters
01:37 PM roycroft: if i cut a joint and there's a 0.003" gap in the joint you will see it
01:37 PM roycroft: you will see it the day that the project is made, and you will see it forever
01:37 PM roycroft: but if there's no gap when i make it, and i use good joinery techniques, you'll never see a gap
01:39 PM Tom_L: just fill it with putty...
01:46 PM roycroft: it's only 11:30 and it's already 30 degrees
01:47 PM roycroft: i'm having dinner with some friends this evening, and we're still only going to outdoor venues
01:47 PM roycroft: it's going to be pretty hot
01:47 PM roycroft: we'll have to have lots of refreshing beverages to keep cool
01:52 PM -!- #linuxcnc mode set to +v by ChanServ
02:00 PM JT-Shop: crap there is a redirect on my admin page
02:31 PM perry_j1987: so hot..
02:36 PM JT-Shop: so far we have not got close to the high of 98F
02:53 PM perry_j1987: wooo success
02:54 PM perry_j1987: got a gcode that is producing a nice machine finish with no burs to deal with afterwards in a second op!
02:58 PM roycroft: i was cleaning up my lamp frame at lunch today, and did a wipe down with mineral spirits when i was finished
02:58 PM roycroft: while it was made of some scraps of ash, i really liked the way the vertical grain parts looked
02:58 PM roycroft: i think quartersawn ash would be great for lamp frames going forward
02:59 PM Roguish: roycroft, hey. read this. very interesting..... https://www.vice.com/en/article/z3xw3x/new-research-vindicates-1972-mit-prediction-that-society-will-collapse-soon
03:01 PM Roguish: and this https://www.theguardian.com/world/2021/jul/28/new-zealand-rated-best-place-to-survive-global-societal-collapse
03:02 PM roycroft: i'm not so sure about that
03:02 PM Roguish: which article ?
03:02 PM roycroft: the first one
03:02 PM roycroft: i haven't looked at the second one yet
03:03 PM roycroft: the url indicates i may agree with it, but i reject the premise that we'll suffer global societal collapse soon
03:04 PM Roguish: i've been seeing this type of article more lately....
03:04 PM roycroft: sure - those types of articles generate a lot of revenue
03:04 PM roycroft: but there are signs of hope as well
03:05 PM roycroft: little, but significant things
03:05 PM roycroft: auto makers starting to really push evs, for example, in spite of right wing and oil company pressore to keep producing gas-guzzlers
03:06 PM roycroft: people in missouri disguising themselves to get vaccinated, because they know that the vaccine works, but would suffer being ostracised if some of their neighbors/family found out
03:06 PM roycroft: that's actually both a negative and a positive
03:06 PM roycroft: but that they're getting the jab is a very good thing
03:07 PM roycroft: even the conversation in our congress has shited on climate change, from denial to blame to acceptance
03:07 PM roycroft: shifted, rather
03:07 PM Roguish: saw that one too. funny
03:07 PM roycroft: the right still don't want to do anything about it
03:07 PM roycroft: but at least they are finally admitting that it's real
03:08 PM roycroft: maybe none of this stuff will be enough
03:08 PM roycroft: but it gives me hope
03:12 PM Roguish: wow, my lithium ETF is over $82 now....
03:29 PM Tom_L: 97F
03:30 PM roycroft: it's going to get hotter than that here today
03:30 PM perry_j1987: tried some of this koolmist #78.. it... is real sticky stuff
03:31 PM perry_j1987: caused a bunch of friction build up
03:31 PM perry_j1987: mixed the 4oz with 1 gallon of water like it said
03:32 PM Tom_L: you're not supposed to use it on wood
03:33 PM perry_j1987: on alum heh
03:33 PM Tom_L: i'm pretty happy with the stuff i use
03:33 PM perry_j1987: which one
03:34 PM Tom_L: http://tom-itx.no-ip.biz:81/~webpage/cnc/Rustlick1.jpg
03:34 PM roycroft: i like wd-40 when machining aluminium
03:35 PM Tom_L: http://tom-itx.no-ip.biz:81/~webpage/rue/Can_Holder/A12_New/A12_4.jpg
03:35 PM Tom_L: decent finish
03:41 PM Tom_L: perry_j1987, what are you making?
03:42 PM perry_j1987: i think i'd still like flood for the lathe since i got the full enclosure
03:42 PM perry_j1987: and no air compressor kicking on randomly
03:43 PM Tom_L: i could go thinner than 4oz since i'm using it on a mist setup
03:44 PM perry_j1987: i got https://www.lubecorp.com/greencut-cutting-fluid/ 5 gallons of this
03:44 PM perry_j1987: someone gave me heh
03:44 PM Tom_L: if you're using flood, you should get a refractometer since it will evaporate in the tank
03:45 PM Tom_L: it's all quite similar
03:45 PM perry_j1987: i have a refractometer
03:45 PM roycroft: and get a smell-o-meter, because it will get funky in the tank over time
03:45 PM Tom_L: i don't worry with it since all i've got is mist
03:54 PM roycroft: 33 now, and still climbing
03:57 PM Tom_L: you have the fires to keep you warm at night
03:58 PM perry_j1987: little sprits of wd-40 sure did make a nice finish heh
04:00 PM roycroft: that's the real problem
04:00 PM roycroft: not the fires
04:00 PM roycroft: but the night time lows are almost a record high
04:00 PM roycroft: usually, even when it gets really hot here, it cools down into the low teens at night
04:01 PM roycroft: but we have lows hovering close to 20 during this heat wave
04:28 PM perry_j1987: man this chip does not want to break
04:28 PM perry_j1987: *aluminum....am-i-right? eh eh? :P
04:36 PM -!- #linuxcnc mode set to +v by ChanServ
04:51 PM * JT-Shop has the drawer parts to thickness and width but not length yet...
04:53 PM perry_j1987: whats the trick to chip breaking with these MGEHR insert holders
05:21 PM enleth: perry_j1987: is the specific insert you have designed for aluminum? MGMN itself does not specify chip breaker geometry
05:22 PM perry_j1987: i have no idea actually
05:23 PM perry_j1987: just came with a holder i got off amazon a while back
05:23 PM enleth: an insert shaped to break steel chips might not be able to do anything useful with aluminum, which is more malleable and will happily curl or slide over the breaker
05:24 PM enleth: so it's probably for steel
05:27 PM perry_j1987: need to stop buying tooling off amazon some day heh
05:27 PM enleth: aluminum inserts are often a bit sharper (less torque needed, so less deflection; the edge is more fragile but it lasts in softer material) and crucially, have a completely different chip breaking system
05:29 PM enleth: just buy a pack of correct inserts and swap them in for the materialba
05:29 PM enleth: *material
05:30 PM enleth: nothing wrong with buying on amazon here
05:34 PM perry_j1987: i got ones here with nubbin in the middle and ones without
05:35 PM CaptHindsight[m]: just got a live center off Amazon, got here early, only 2 days
05:38 PM perry_j1987: they all say steel and non ferrous materials on amazon for these inserts heh
05:39 PM enleth: perry_j1987: compare them, maybe one will be better, but it's hard to assign a specific breaker shape back to its intended purpose
05:40 PM enleth: perry_j1987: see if one feels sharper, that has a better chance of correlating with the design intent being to cut aluminum
05:40 PM enleth: but sharper steel inserts exist too
05:40 PM solarwind: So I'm going to transport my own acetylene cylinder tomorrow as I continue with the scrapping operation just in case the one they have on site runs out
05:40 PM * CaptHindsight[m] putting a racket type bug zapper on robot arm for active flying insect management
05:41 PM solarwind: I know you can't store them horizontally, or you have to wait a while after standing them up vertically after use
05:41 PM CaptHindsight[m]: avoid quick stops/starts as well as collisions with flaming vehicles
05:41 PM solarwind: But I'm a bit uncomfortable transporting it vertically in the bed of my pickup
05:42 PM solarwind: Is there a compromise? That is, if I orient it at a 45º angle, would that help reduce the time I need to let it sit vertically before use?
05:42 PM CaptHindsight[m]: fine if properly strapped and out of sniper range
05:43 PM solarwind: I'm actually not sure of the reason you can't store them horizontally and use immediately. The company I got the cylinder from said if I transport it horizontally, I have to let it sit vertically for at least as long as it was laying horizontally before use
05:43 PM CaptHindsight[m]: https://www.osha.gov/laws-regs/standardinterpretations/1992-05-05-0
05:43 PM CaptHindsight[m]: 2. Acetylene cylinders are secured against movement in all directions in a rack secured to the segment car. The tops of all acetylene cylinders are elevated so that the cylinders are inclined at an angle of not less than 30 degrees from horizontal (to protect against loss of acetone).
05:43 PM Tom_L: doesn't acy have some solids inside the bottle?
05:44 PM Tom_L: that's why they need to be vertical
05:44 PM CaptHindsight[m]: https://jtcylinderracks.com/safety-tips-to-keep-your-acetylene-tanks-from-exploding/
05:45 PM solarwind: As far as I know, it's stored in a porous substrate mixed with acetone to keep it stable
05:45 PM Tom_L: All acetylene cylinders contain a porous honeycomb material called a monolithic mass. They also contain a solvent (acetone) which is absorbed by the porous mass. The acetylene dissolves in the acetone and holds the acetylene in a stable condition
05:46 PM Tom_L: don't rock the boat
05:46 PM solarwind: The cylinder on site hasn't run out yet, so I suppose I can bring my cylinder there by transporting it horizontally and just let it sit vertically overnight before using it. I think there's enough acetylene on site to last a day
05:48 PM solarwind: Ah, so I suppose transporting it at ~30º would be reasonable. That should decrease the height significantly
05:48 PM enleth: a block of wood with a semicircular cutout on top is handy for this
05:48 PM solarwind: 30º from horizontal is actually quite low. So 45º should be totally fine. I guess that answers that question. Thanks!
05:49 PM solarwind: enleth yes, I actually planned to do exactly that to secure the cylinders for transport
05:50 PM solarwind: Then I'll tie it down, give it a good pat, and firmly grunt "that's not goin' anywhere" for good measure
05:52 PM enleth: modern acetylene bottles are the result of many decades of fires and explosions, they're pretty damn safe
05:53 PM enleth: just remember, if one starts making noises on its own, GTFO and call the fire department
05:54 PM solarwind: Yeah, I'm quite safe about these things. I always use flashback arrestors, mind my consumption rate, etc.
05:55 PM solarwind: Only use pump air rifles with small lead pellets for target practice and aim for the bottle instead of the valve; safety conscious
05:56 PM enleth: the modern ones actually slow the rate of decomposition of acetylene so much down that you might get as much as an hour from the moment it starts growling at you to the rupture
05:56 PM solarwind: Yup, that's what the gas supply company told me
05:56 PM solarwind: Longer than an hour actually
05:56 PM enleth: plenty of time for the fire brigade to try cooling it down to prevent it
05:57 PM solarwind: But it still boggles my mind why every acetylene regulator I've seen allows adjustment beyond 15 PSIG
05:58 PM enleth: but don't try to be smart and vent it yourself if you ever end up in this situation, it'll agitate the insides so much that the rate of venting won't keep up with decomposition
05:58 PM roycroft: assuming you can schedule an appointment with the fire brigade in a reasonable time frame
06:00 PM solarwind: Of course, no reason to try and be a hero. Evacuate the building and call 911
06:00 PM solarwind: There's definitely enough time. You have more than an hour from the time it starts decomposing inside the cylinder
06:05 PM solarwind: Actually, such an event would be a reasonable and legal use of the fire alarm right?
06:48 PM roycroft: and it's up to 37 now, with another hour of warming, so we should reach the forecast high of 38 in spite of the overcast skies
06:49 PM roycroft: tomorrow's forecast has been updated to a high of 39
06:50 PM CloudEvil: roycroft: Good luck.
07:01 PM roycroft: yeah, i have to deal with blackberries tomorrow
07:01 PM roycroft: the last of them, fortunately
07:01 PM roycroft: but i'm not sure i'll be able to work outside for very long
07:09 PM Tom_L: 3rd shift :)
08:30 PM Eric_: A while back, I went to get acetylene and the guy in line in front of me took his acetylene bottle and threw it about 10 feet into the bed. Where it could just roll around.
08:31 PM Eric_: plumber, I think
08:32 PM Eric_: and then they gave me a tank that was leaking
08:32 PM Eric_: not sure how that place hasn't blown up
08:43 PM XXCoder: geez
10:59 PM -!- #linuxcnc mode set to +v by ChanServ