#garfield Logs

Feb 12 2021

12:58 PM rue_mohr: ...morning
01:46 PM rue_mohr: so, I been going round in circles on the editor thing
01:46 PM rue_mohr: I'v worked out that there are multiple similar objectives that are not mutual
01:48 PM rue_mohr: I'v realized that most of the complexity is from vertical movement, and modification of "non file" space
01:48 PM rue_mohr: but most of the conclusion, is that the code I have, is prettmuch on track
01:49 PM rue_mohr: even tho it doesn't feel like it
02:15 PM Tom_itx: :)
02:23 PM Tom_itx is now known as Tom_L
06:33 PM rue_mohr: ok, hilighting seems best done by building a 1:1 attribute map and then spooling it RLE style
06:36 PM Tom_L: rle?
06:39 PM Tom_L: ok maybe i'll double check the program and start on it. but it's awfully cold out there
06:45 PM Tom_L: https://www.wfaa.com/video/news/local/raw-aerial-footage-of-massive-pileup-crash-on-i-35w-in-fort-worth/287-89035390-9bfc-4606-b3a0-2570da6eee88
06:45 PM Tom_L: 133 cars... black ice
06:54 PM rue_mohr: run length encoded
06:55 PM rue_mohr: yea, people will disregard it, even if they know, then say that the crashes are part of life and are unavoidable.
06:56 PM rue_mohr: people repeatedly insist on disregarding warnings when I point stuff out, they say I'm making things complicated
06:57 PM rue_mohr: meh
07:07 PM Tom_L: so
07:07 PM Tom_L: where you at on the editor?
07:09 PM rue_mohr: text colouring
07:09 PM rue_mohr: which is kin to syntax hilighting and find hilights
07:09 PM Tom_L: i wonder if i should cut the threads a little on the big side
07:09 PM rue_mohr: and multiple cursors
07:09 PM Tom_L: instead of 1.50 maybe 1.505
07:10 PM rue_mohr: how deep is the thread all togethor? .07?
07:10 PM rue_mohr: ish?
07:10 PM rue_mohr: I find it hard to judge by eye
07:10 PM Tom_L: .0677
07:10 PM rue_mohr: oh yea I'm WAY off...
07:10 PM rue_mohr: :D
07:10 PM Tom_L: not if you round it
07:11 PM rue_mohr: your plan sounds good to me
07:11 PM Tom_L: cut it a tiny bit oversize?
07:11 PM Tom_L: i mean, technically it _should_ fit
07:11 PM rue_mohr: yea, better a tiny bit loose than too tight
07:11 PM rue_mohr: yea
07:12 PM Tom_L: maybe .002 or .003 over
07:12 PM Tom_L: x2 would be 4 - 6
07:12 PM rue_mohr: in the context of .07, .005 sounds safe
07:12 PM rue_mohr: ah, k
07:12 PM rue_mohr: yea
07:13 PM Tom_L: then at 300 psi i don't want it to blow off either
07:14 PM rue_mohr: its not air
07:14 PM rue_mohr: if it pops, it hops up an inch and squirts a teaspoon of water
07:14 PM Tom_L: i think i'll do the .002 or .003 over
07:14 PM rue_mohr: in a cage
07:14 PM rue_mohr: hmm I need to make a cage
07:15 PM rue_mohr: nice welding project to start the year off
07:16 PM Tom_L: so that won't affect anything else except re'running the thread macro with different numbers
07:19 PM Tom_L: so which would you do? .002 or .003?
07:19 PM rue_mohr: lets do 3
07:19 PM Tom_L: 1.502 vs 1.503
07:19 PM Tom_L: ok
07:19 PM rue_mohr: .05 total would be 1/14th of the thread dep
07:20 PM rue_mohr: if my head is screwed on right
07:20 PM rue_mohr: I'd think even up to half a thread dep would hold
07:20 PM rue_mohr: but wouldn't want to be that far
07:33 PM Tom_L: ok that makes it .0113 R bigger
07:33 PM Tom_L: not much
07:33 PM Tom_L: that was with .003
07:34 PM Tom_L: want me to do .005?
07:35 PM Tom_L: oh nevermind that's .010 not .0010
07:35 PM Tom_L: so roughly .020 diameter bigger on the major diameter
07:35 PM Tom_L: i'll run it with .002 and see
07:36 PM rue_mohr: oo
07:36 PM rue_mohr: so .14 total thread depth to .02 overcut
07:37 PM rue_mohr: total
07:40 PM Tom_L: something is fishy
07:40 PM Tom_L: just a sec
07:40 PM Tom_L: i got .0116 on that one
07:44 PM Tom_L: i was measuring the wrong path
07:45 PM Tom_L: i cut 2 passes and i was overlapping 2 macro runs and checking the difference in distance but it picked up pass 1 & 2 instead of cut 1 & 2 :)
07:46 PM rue_mohr: can that thread be done in one cut?
07:46 PM Tom_L: sure
07:46 PM Tom_L: i generally do 2 though
07:46 PM rue_mohr: k
07:46 PM Tom_L: divide the load equally between all passes
07:46 PM rue_mohr: same macro, different offset
07:47 PM rue_mohr: right
07:47 PM Tom_L: number of passes
07:47 PM Tom_L: i found the spot i need to measure now i just need to rerun it and check it
07:48 PM Tom_L: the distance won't be near what we thought
07:50 PM Tom_L: ok so with 1.503 i get .001 difference on the radius
07:50 PM Tom_L: from 1.500
07:50 PM Tom_L: should i try .005?
07:50 PM rue_mohr: yea
07:51 PM Tom_L: so remember that and i'll run 1.505
07:51 PM rue_mohr: how many thou is usually on a heat-shrink fit?
07:53 PM Tom_L: press fit you mean?
07:53 PM Tom_L: it depends on the diameter
07:54 PM Tom_L: .0005 to .0015 i'd guess
07:54 PM Tom_L: maybe a bit more
07:56 PM rue_mohr: so, maybe +0.002 on the dia then?
07:56 PM Tom_L: ok 1.505 gives .0017 difference
07:57 PM Tom_L: i think that's probably a good number to go with
07:57 PM rue_mohr: ok
07:57 PM Tom_L: wait
07:57 PM Tom_L: the final pass on 1.505 is .0025" difference
07:57 PM Tom_L: i was measuring the first pass
07:57 PM Tom_L: ^^ that's the final one
07:57 PM rue_mohr: still much less than 1/2 a thread dep
07:58 PM Tom_L: so i'll go with 1.505 major diameter
07:58 PM rue_mohr: :) with all the carefull care I sure hope it fits!
07:58 PM Tom_L: better chance of it working with not way to test it
07:59 PM Tom_L: unless there are no objections...
07:59 PM Tom_L: :)
08:00 PM Tom_L: lemme run .003 now that i know what to measure...
08:00 PM rue_mohr: hmmm, this project origionally used a "render buffer"
08:00 PM Tom_L: ya gotta zoom way in to check it and that makes it tricky to find the right path
08:00 PM rue_mohr: I removed it in the process of the rewrite, but in context of hilighting it makes more sennse
08:02 PM Tom_L: ok 1.503 gives .0015" radius bigger
08:02 PM rue_mohr: ah my test came back covid free
08:02 PM rue_mohr: so I have a different problem, thats good
08:02 PM rue_mohr: so .0015 / 0.07
08:02 PM Tom_L: so either .0015 or .0025 oversize?
08:03 PM rue_mohr: sounds safe
08:03 PM Tom_L: 1.503 or 1.505
08:03 PM Tom_L: and that makes sense because it's .002 difference on the diameter
08:04 PM rue_mohr: even 3 thou should be enough to clear
08:04 PM Tom_L: ok i'll go with 1.503
08:04 PM Tom_L: ?
08:04 PM rue_mohr: sure
08:04 PM rue_mohr: 7 thou is a find hair?
08:05 PM Tom_L: .002 - .003
08:05 PM rue_mohr: where is a hair...
08:05 PM rue_mohr: that ones 4 thou...
08:05 PM rue_mohr: 7 yea
08:06 PM Tom_L: so which one?
08:06 PM rue_mohr: 2
08:06 PM Tom_L: 1.505?
08:06 PM rue_mohr: which is 1/14th of a thread dep
08:07 PM Tom_L: 1.505 gives .0017 difference
08:07 PM rue_mohr: dia
08:07 PM Tom_L: r
08:08 PM rue_mohr: .002/.07
08:08 PM rue_mohr: limit .035
08:08 PM Tom_L: .0034 diameter
08:08 PM rue_mohr: and if you go by press-fit, .002 limit the other way
08:08 PM rue_mohr: so between .002 and .035 delta radius is the margin
08:08 PM Tom_L: 1.505 is a safer bet
08:09 PM rue_mohr: which is .003?
08:09 PM Tom_L: and i don't think it will be too loose
08:09 PM rue_mohr: ok
08:09 PM rue_mohr: you probably have a better instinct for it
08:09 PM Tom_L: 1.505 gives .0017 difference radius .0034 diameter
08:09 PM rue_mohr: every time I try to make things a perfect fit they come out a press-fit
08:10 PM Tom_L: you just measured a hair.. how much end stink do you need?
08:10 PM Tom_L: i just didn't want it to end up too sloppy
08:10 PM Tom_L: that's a fairly coarse thread though
08:11 PM rue_mohr: heh
08:11 PM rue_mohr: pretty fine to me
08:11 PM Tom_L: my brass cup was 24
08:11 PM rue_mohr: yea..
08:11 PM rue_mohr: what did you make the differece on those?
08:11 PM Tom_L: http://tom-itx.no-ip.biz:81/~webpage/cnc/Brass_cup/Brass_Cups5.jpg
08:12 PM Tom_L: i have no idea now :)
08:12 PM Tom_L: i think i went with the nominal numbers
08:12 PM rue_mohr: do they include a gap?
08:13 PM Tom_L: ID: .3299 OD: .3239
08:13 PM Tom_L: so .006 D difference
08:14 PM Tom_L: and they're plenty loose
08:14 PM Tom_L: about like the average nut / bolt fit
08:17 PM rue_mohr: if they hold at that
08:17 PM rue_mohr: and this is courser
08:18 PM rue_mohr: ?
08:18 PM Tom_L: they're a 'good' fit on the loose side
08:18 PM rue_mohr: so, the id is ~1.5
08:19 PM Tom_L: on which?
08:19 PM rue_mohr: Area is : 1.767146
08:19 PM rue_mohr: calc 300*1.767146
08:19 PM rue_mohr: 300*1.767146 -->> 530.144
08:19 PM rue_mohr: 530lbs on the cap
08:19 PM Tom_L: on your part the id is 1.4323
08:19 PM rue_mohr: ok
08:20 PM rue_mohr: 483.369
08:20 PM rue_mohr: lbs
08:20 PM rue_mohr: if ~7 threads enguage
08:20 PM rue_mohr: ~70lbs a thread
08:20 PM rue_mohr: huh
08:24 PM Tom_L: ok 12 threads (maybe 1 or 2 are above the part) starting .050" from the bottom
08:24 PM Tom_L: + 1/2 a thread
08:24 PM Tom_L: the bottom of the cutter
08:24 PM Tom_L: is .050 from the floor
08:25 PM rue_mohr: I can give it a 0.1" seal
08:25 PM Tom_L: so your gasket should be ok
08:25 PM rue_mohr: or two
08:25 PM Tom_L: yeah that should work
08:25 PM rue_mohr: depends how much comrpession
08:25 PM Tom_L: i don't wanna try to get it much closer
08:25 PM rue_mohr: sounds fine,I'd never get that close meself
08:25 PM Tom_L: and i don't have a good way to undercut the bottom for a relief
08:25 PM Tom_L: you could do that on your lathe
08:26 PM Tom_L: or i suppose i could
08:26 PM rue_mohr: I think I put a 0.2" undercut on mine, but it works with a plate
08:26 PM Tom_L: just a notch at the bottom so the tank would thread clear to the bottom
08:26 PM rue_mohr: not that I could thread it..
08:26 PM Tom_L: no just to cut the relief
08:26 PM rue_mohr: dont need an undercut
08:26 PM Tom_L: just a notch
08:26 PM Tom_L: it's very common practice
08:27 PM rue_mohr: indeed, I can
08:27 PM rue_mohr: if its not 5 sided :)
08:27 PM Tom_L: it allows the tank to thread clear to the bottom
08:27 PM rue_mohr: make me break out the plate :)
08:27 PM rue_mohr: I think the tank is like 5 threads
08:27 PM Tom_L: we'll see what happens... i may have something i can notch it with on my lathe
08:27 PM rue_mohr: if more, not by tooo much
08:28 PM Tom_L: we don't want you to break a sweat :)
08:28 PM rue_mohr: :/
08:28 PM rue_mohr: I really hope I get lots done once the weather unfreezes
08:29 PM Tom_L: ok i think i'm happy with this
08:29 PM rue_mohr: I been hiding in the house while I'm ill, my shop is getting lonely
08:30 PM rue_mohr: so... a render buffer...
08:30 PM Tom_L: so what size drill do you use on a 1/2 npt tap?
08:30 PM rue_mohr: ooo
08:31 PM rue_mohr: brb
08:31 PM Tom_L: realistically it would be a taper but i don't have any taper drills
08:32 PM Tom_L: 45/64
08:32 PM rue_shop1: 23/32
08:32 PM Tom_L: .703
08:32 PM Tom_L: ok so i don't know if i have one
08:32 PM Tom_L: my set stops at .500
08:33 PM rue_shop1: I have one
08:33 PM Tom_L: but i have a pile of bigger drills
08:33 PM rue_shop1: I got a bunch of crazy bits
08:33 PM rue_shop1: twice
08:33 PM Tom_L: i get big ones per job
08:33 PM rue_shop1: yea get the job to pay for them :)
08:33 PM * Tom_L goes to the cold shop to check
08:34 PM rue_shop1: oh no worries, I have to do a fire department connection cap anyhow
08:34 PM rue_shop1: the pressure test thing is expanding
08:35 PM rue_shop1: shop is COLD I'll leave on a 60w header
08:35 PM rue_shop1: heater
08:37 PM rue_mohr: ok I need to think about how to do a render buffer
08:38 PM Tom_L: haha i have a .703 (45/64)
08:38 PM Tom_L: i must have gotten that when i bought the tap
08:39 PM Tom_L: that way if it's too shallow you can run the tap deeper
08:39 PM Tom_L: 23/32 would make it looser
08:39 PM rue_mohr: huh
08:40 PM rue_mohr: 46/64 vs 45/64
08:40 PM Tom_L: .718 vs .703
08:41 PM Tom_L: maybe i'll start on it tomorrow
08:41 PM Tom_L: dunno what else is going on
08:42 PM Tom_L: if the threads hold you certainly don't need to worry about the cap blowing. it'll have a .250" wall thickness min
09:28 PM Tom_L: ok gcode ready
09:32 PM Tom_L: http://tom-itx.no-ip.biz:81/~webpage/rue/extinguisher_nut/extinguisher_cap.txt
10:34 PM rue_shop1: oo!
10:35 PM rue_shop1: drill before milling it out?
10:36 PM Tom_L: just a pilot hole i think
10:37 PM Tom_L: i was gonna do a .250 hole to ease the endmill plunge but it'll be ok
11:02 PM aandrew: so I built this little test fixture for RFID characterization
11:03 PM aandrew: just a motor on a leadscrew that moves the card back and forth, and just because I can, I have a little VL53L0x distance sensor
11:04 PM aandrew: just used an arduino nano and adafruit's stuff and cursed it mightily because the damn sensor wasn't working
11:05 PM aandrew: finally tried another module (got 2) and it worked, so I guess I got a bum one
11:06 PM aandrew: they are pretty noisy (and minimum 50mm distance which I didnt' realize)
11:07 PM aandrew: I threw an ewma filter on it and it seems to have some low frequency drift on the order of a couple minutes where it varies about +/-3mm
11:10 PM aandrew: got the VL6180 coming in which has a 5-100mm range which is more what I need
11:35 PM rue_shop1: :( I just put the first ding in the drill press table
11:35 PM rue_shop1: 1981, and I JUST hit it
11:46 PM rue_mohr: :( its first ding
11:46 PM rue_mohr: and its a doozie
11:46 PM rue_mohr: thought I was over the hole and that the sacraficial was deep enough