#garfield Logs

Feb 25 2021

01:50 AM polprog: rue_mohr: ive gotta build it first, got a lot of catching up :(
09:48 AM polprog: ok, today seems less cluttered
02:50 PM splyne is now known as spline
04:55 PM polprog: https://www.oocities.org/zl2pd/Varicap.html
04:55 PM polprog: that 10-50 MHz osc looks quite easy
04:56 PM polprog: funny to think that a year ago id have no idea what's going on there and now i just needed to stare at it for a minute or so
04:56 PM polprog: thanks to rue among others :)
04:59 PM polprog: i should re-try this project now that i know a little more about oscillators
04:59 PM polprog: https://polprog.net/rozne1/ircjunk/gal/pll/
04:59 PM polprog: and i have a stable ref clock generator
04:59 PM polprog: because the hct14 oscillators that were supposed to be free running liked to lock to eachother themselves
05:08 PM polprog: ive got some transistors that could work in the 100+MHz range, i should try them
05:26 PM Tom_L: hahaha rue_mohr
05:27 PM Tom_L: guess what?
05:27 PM Tom_L: 2:55 pm
05:27 PM Tom_L: Delivered to your community mailbox, parcel locker or apt./condo mailbox
05:27 PM Tom_L: Roberts Creek, BC
05:27 PM polprog: :o
05:29 PM Tom_L: damn that must be a first for canada post! 2 days early?
09:00 PM rue_mohr: I'll go check!
09:15 PM rue_mohr: oh no peanute!
09:15 PM rue_mohr: oh no peanuts!
09:15 PM rue_mohr: woof
09:15 PM rue_mohr: thats got to be good for 500 psi eh!?
09:17 PM rue_mohr: I'll see if I can test it on the weekend!
09:19 PM Tom_L: nice! glad you got it finally
09:21 PM rue_mohr: rang him up, he hasn't had time yet
09:21 PM rue_mohr: I'll go test in on sat
09:22 PM rue_mohr: hmm, did you notice the slight depth mismatch on the threads?
09:23 PM rue_mohr: we will find out if it works!
09:23 PM Tom_L: depth mismatch?
09:24 PM Tom_L: where?
09:24 PM rue_mohr: ok, so
09:24 PM rue_mohr: the flats were put to the left and right yes?
09:25 PM Tom_L: they were there
09:25 PM Tom_L: on the OD?
09:25 PM rue_mohr: its on the thread, just a sec
09:25 PM rue_mohr: the pocket mill
09:25 PM Tom_L: not sure what you mean
09:25 PM rue_mohr: did it traverse to the left or right after the pocket?
09:26 PM rue_mohr: the pocket mill, after circling, went to a side
09:26 PM Tom_L: after it did an arc to the center of the pocket
09:26 PM Tom_L: oh i know what you mean
09:26 PM Tom_L: yeah i saw that
09:26 PM Tom_L: i don't think it will bother anything
09:27 PM rue_mohr: no I dont either
09:27 PM Tom_L: and i'm not sure what caused it
09:27 PM Tom_L: if it was on both sides i'd say backlash but it's not
09:27 PM rue_mohr: with the thread it looks like the dia was slightly out when It finished comming around
09:27 PM Tom_L: probably where the pocket tool retracted is all i can think
09:28 PM rue_mohr: ok
09:28 PM Tom_L: it's got a chamfer on the top of the thread
09:28 PM Tom_L: same as the outside
09:28 PM rue_mohr: that same side is there the thread changes dia just a bit
09:29 PM rue_mohr: I think its on the left side
09:29 PM Tom_L: i've seen that on pipe chasers too
09:30 PM rue_mohr: heck of a day at work
09:30 PM rue_mohr: raced to replace a phone system in 8 hours
09:30 PM rue_mohr: me a co-worker
09:30 PM Tom_L: heh
09:31 PM rue_mohr: both pedaling about as fast as we could
09:31 PM rue_mohr: finished just as they were trying to leave
09:31 PM Tom_L: got a head cold... feelin kinda crappy
09:31 PM rue_mohr: so much for training
09:31 PM rue_mohr: :/
09:31 PM rue_mohr: where is the path screenshot you took there?
09:31 PM Tom_L: the cad file?
09:32 PM rue_mohr: you took a snapshot of the path render
09:32 PM rue_mohr: https://twitter.com/alispagnola/status/1364647442998648833
09:33 PM rue_mohr: oh you kinda want sound for that one too :/
09:33 PM rue_mohr: its the silly video for the day, sounds pretty good, considering
09:33 PM Tom_L: i dunno if i took a screenshot of that
09:34 PM rue_mohr: my plumber buddy for a big belt sander for a steal and asked for me to look at changing it to 240, cause it was gutless
09:34 PM rue_mohr: my suspicion was right, it was gutless cause it was already set to 240
09:35 PM Tom_L: you want just the thread?
09:35 PM rue_mohr: well, I'm curious to see
09:35 PM aandrew: dammit rue
09:36 PM rue_mohr: haha
09:37 PM Tom_L: http://tom-itx.no-ip.biz:81/~webpage/rue/extinguisher_nut/extinguisher_cap_path.JPG
09:37 PM aandrew: I've been earwormed by door stoppers
09:37 PM aandrew: this is a first
09:37 PM rue_mohr: pretty damn good considering isn't it?
09:37 PM aandrew: indee
09:37 PM aandrew: d
09:39 PM rue_mohr: Tom_L, yea, its to the right
09:39 PM rue_mohr: is the right side where the spirals re-start?
09:39 PM rue_mohr: macro wise?
09:40 PM Tom_L: http://tom-itx.no-ip.biz:81/~webpage/rue/extinguisher_nut/extinguisher_cap_path2.JPG
09:40 PM Tom_L: yeah probably
09:40 PM Tom_L: you can see the yellow leadin - out moves there
09:40 PM Tom_L: top and bottom but not in the middle
09:40 PM rue_mohr: whats odd tho, is that the milling bit did it too
09:41 PM Tom_L: that's where the pocket cutter retracts
09:42 PM rue_mohr: huh, I wonder what it is..
09:42 PM rue_mohr: where is my todo list!
09:42 PM rue_mohr: I'm all excited to try this and I cant till sat :/
09:42 PM Tom_L: if it were backlash you should see it on both sides and i didn't
09:42 PM rue_mohr: yea
09:43 PM Tom_L: you think they're close enough to the bottom?
09:43 PM rue_mohr: yes
09:43 PM Tom_L: i could have gone maybe .040" more
09:43 PM rue_mohr: looking at it, I'm wondering is there is tooo much thread!
09:43 PM Tom_L: cut it off :)
09:43 PM rue_mohr: I can add extra gaskets tho
09:43 PM rue_mohr: My mental image is all out cause the size doens't even look right to me
09:44 PM rue_mohr: I kinda picture the neck looking larger
09:44 PM rue_mohr: its not tho
09:44 PM Tom_L: we'll see
09:44 PM rue_mohr: I cant recall clearly how much space there is between the top of the tank and the top of the thread
09:45 PM Tom_L: i've found my thread cutters shoulder starts at about the maximum threads you would cut for a given size
09:46 PM aandrew: lol twitter offering a way to montize access to your tweets
09:46 PM Tom_L: i used my 3/8" cutter on those
09:46 PM rue_mohr: aandrew, I'm really starting to question how tweet distribution works
09:46 PM rue_mohr: I'd bet, even if your looking at latest tweets first, all of mine wont be there
09:47 PM rue_mohr: Tom_L, is a deep one!
09:47 PM Tom_L: ~10 or so good threads
09:48 PM rue_mohr: yea
09:48 PM Tom_L: you can always shorten it on the lathe and chamfer the threads again
09:48 PM rue_mohr: I'd rather just add gaskets
09:49 PM Tom_L: even a hard gasket under the rubber one
09:49 PM Tom_L: like a nylon washer etc
09:50 PM rue_mohr: totally, it might clear just fine
09:50 PM rue_mohr: oh I'm supposed to make a cutter for a guy too
09:51 PM rue_mohr: and empty the truck
09:51 PM rue_mohr: and process the hearing data for ma
09:51 PM rue_mohr: but we discovered she has a really strange issue in her right ear that causes the hearing to go in and out
09:51 PM Tom_L: http://tom-itx.no-ip.biz:81/~webpage/cnc/Brass_cup/Brass_Cups5.jpg
09:51 PM rue_mohr: which did NOT show up in the hearing test she had done
09:52 PM Tom_L: i didn't notice that on that part
09:53 PM Tom_L: yeah it's there too slightly
09:53 PM Tom_L: just one spot though
09:53 PM rue_mohr: its really hard to make out in a photo
09:53 PM rue_mohr: I tried to pick up the one here, but its indistinguishable from the way the light falls on things
09:54 PM Tom_L: i think it's at the start point of each helix
09:54 PM rue_mohr: yea, I wonder if the radius drifts?
09:55 PM Tom_L: actually on this one it's not that, it's where the pocket tool retracted
09:55 PM Tom_L: i think that's what it might be
09:55 PM Tom_L: it goes straight up
09:55 PM rue_mohr: but the thread here is a full cut, and its slightly there
09:55 PM Tom_L: i'm not sure
09:55 PM rue_mohr: oh wait, yea, the...
09:56 PM rue_mohr: there is a slight flat on the threads
09:56 PM rue_mohr: maybe it took the radius a bit shallow under load
09:57 PM Tom_L: the pocket or thread?
09:57 PM rue_mohr: the pocket
09:57 PM Tom_L: could be
09:57 PM rue_mohr: are threads 100%?
09:57 PM Tom_L: should be
09:57 PM rue_mohr: k
09:57 PM Tom_L: i'm not really sure
09:58 PM Tom_L: i went off those charts
09:58 PM Tom_L: so it may be 75%
09:58 PM rue_mohr: if they were 90% or something it might be easier to tell
09:58 PM rue_mohr: they look 100, if the pocket was small, it would bring up the % of thread
09:58 PM Tom_L: but it comes to a sharp point so it probalby is 100%
09:58 PM rue_mohr: hard to tell with the reflections!
09:59 PM Tom_L: 1.4323 ID
09:59 PM Tom_L: look it up
09:59 PM Tom_L: the OD was 1.5 but i took it to 1.503
09:59 PM Tom_L: which would hardly be noticeable
10:00 PM rue_mohr: I think someone swiped my desk-calipers
10:00 PM Tom_L: i wouldn't check it too close :)
10:00 PM Tom_L: it's a home built hobby mill
10:00 PM rue_mohr: :)
10:01 PM Tom_L: gonna try to get some sleep and get rid of this head full
10:03 PM rue_mohr: I'm really tired
10:04 PM Tom_L: you gonna show the other guy?
10:04 PM rue_mohr: yea!
10:05 PM Tom_L: oh great
10:05 PM rue_mohr: heh
10:05 PM rue_mohr: I'll point to his camp stove cap and say 'same guy' :)
10:07 PM rue_mohr: ooh the shop is on
10:18 PM Tom_L: camp stove cap?
10:18 PM aandrew: ok dumb mechanical question. What's the difference between a sleeve bearing and a bushing? they look like they do the same thing
10:19 PM Tom_L: sleeve bearing would be like a roller bearing
10:19 PM Tom_L: i think
10:20 PM aandrew: when I look up 3/16" sleeve bearings and bushings I seem to get the same kind of thing
10:20 PM aandrew: brass "tube" with a specific ID
10:20 PM Tom_L: could be just how different ppl call them
10:21 PM Tom_L: technically a sleeve bushing is a bearing surface
10:22 PM aandrew: I've got some 3/16" smooth rod, I was thinking of using 5mm sleeve bearings with it
10:22 PM Tom_L: https://r7knmqt3qn1hbgxc30yrat1a-wpengine.netdna-ssl.com/wp-content/uploads/2018/02/omniCOOL-figure-1_sleeve-bearing-sized.jpg
10:22 PM aandrew: it's not going to be a perfect fit, but 0.2mm of slop is close enough for my purposes
10:22 PM rue_mohr: cintered, oil impregnated bushings
10:22 PM rue_mohr: quiet
10:22 PM Tom_L: i was trying to remember what that was called :)
10:23 PM aandrew: https://www.amazon.ca/gp/product/B07ZJ18HZS specifically those
10:23 PM aandrew: I can get 'em a lot cheaper off ali if I want to wait
10:23 PM rue_mohr: no
10:23 PM aandrew: but fastenal doesn't have 'em which surpised me
10:23 PM rue_mohr: no those
10:23 PM Tom_L: it's difficult to machine those too
10:23 PM Tom_L: the cinterd ones
10:23 PM rue_mohr: ok I can go take a pic and turn my shop off
10:24 PM aandrew: or rather fastenal has a bunch but they're all "ship from mfg" which means almost ali ship times
10:25 PM Tom_L: brass rod wouldn't be as good
10:25 PM Tom_L: you need an oil channel or porous material to hold the oil in
10:25 PM aandrew: yeah the 3/16 brass rod was from $unknown so part of the reason why I was looking at that 0.2mm slop
10:26 PM aandrew: https://www.amazon.ca/gp/product/B08GSCB1HL are the rods
10:26 PM Tom_L: for a low speed application brass might be ok
10:26 PM Tom_L: like a crank handle etc
10:27 PM aandrew: these are guide rails, so yeah low speed
10:27 PM Tom_L: C27400 is the type of brass
10:27 PM Tom_L: i think
10:28 PM Tom_L: https://alloys.copper.org/alloy/C27400
10:28 PM aandrew: https://www.fastenal.com/products/details/0434611 is what fastenal's got
10:29 PM Tom_L: those would be better if they fit
10:29 PM Tom_L: bronze
10:29 PM Tom_L: cintered
10:29 PM rue_mohr: how many do you need?
10:29 PM rue_mohr: http://ruemohr.org/~ircjunk/tempimage/p1180755.jpg
10:29 PM rue_mohr: http://ruemohr.org/~ircjunk/tempimage/p1180757.jpg
10:29 PM rue_mohr: http://ruemohr.org/~ircjunk/tempimage/p1180758.jpg
10:29 PM rue_mohr: those
10:30 PM aandrew: rue_mohr: like 4. wow that's a pile. The OD is a bit of a tricky bit, tryign to make it fit into lego still :-)
10:30 PM rue_mohr: ok
10:30 PM aandrew: Tom_L: so how come the fastenal ones would be better?
10:30 PM rue_mohr: so
10:30 PM rue_mohr: wait
10:30 PM Tom_L: cintered bronze
10:30 PM rue_mohr: you need how many?
10:30 PM Tom_L: bronze has more tin i think
10:31 PM Tom_L: i forget now
10:31 PM Tom_L: they call it powdered bronze
10:31 PM aandrew: rue_mohr: maybe four
10:31 PM aandrew: it's just for guide rails
10:31 PM rue_mohr: ok
10:31 PM rue_mohr: and you want it to fit lego rail?
10:31 PM rue_mohr: how big is lego rail?
10:31 PM Tom_L: print some?
10:31 PM aandrew: or rather the 3/16 bronze rod is the guide rail, I was going to melt a few bushings into the lego
10:32 PM aandrew: to create a tight but low friction guide
10:32 PM Tom_L: what ID?
10:32 PM rue_mohr: brb got lego, headed to shop
10:33 PM aandrew: rue_mohr: um. standard lego height. the diameter of the hole in the lego is 4.8mm which is 3/16" exactly
10:33 PM aandrew: hm
10:33 PM aandrew: maybe I don't need the bushing
10:33 PM aandrew: I thought it was wider
10:33 PM aandrew: brb getting lego
10:33 PM rue_shop1: dont you have a 3d printer?
10:34 PM rue_shop1: lego hole seems to be 4.75mm
10:34 PM rue_shop1: shaft is 4.73mm
10:35 PM aandrew: yep I'm overthinking
10:35 PM rue_shop1: that might be 3/16"
10:35 PM aandrew: brass rod is 4.8mm, hole in the lego is 4.8mm+
10:35 PM aandrew: 4.8mm is 3/16" yes
10:36 PM rue_shop1: 3/16" -> 4.76mm
10:36 PM aandrew: that explains why there's a bit of slop still
10:36 PM rue_shop1: ok, so
10:36 PM aandrew: rue_mohr: what's the 3d printer got to do with it? I thought about printing something but I'd end up spending more time with that than just adapting the lego
10:37 PM rue_shop1: cause I have a 3d printed lego brick
10:37 PM aandrew: which isn't a bad distraction but unfortunately I haven't got a lot of time to be distracted
10:37 PM rue_shop1: if you want to change the rod size, the 3d printed brick can hold the bushing
10:37 PM aandrew: oh you built a model? I found a bunch on thingiverse and should try printing again now that my printer's much better set up
10:37 PM rue_shop1: ok, but
10:38 PM rue_shop1: were looking for 4 3/16 bushings
10:38 PM aandrew: yes, because I thought that the hole in the lego was larger than that
10:38 PM rue_shop1: 8mm...
10:38 PM aandrew: but the hole in the lego is just slightly larger than 3/16" (4.8mm)
10:38 PM rue_shop1: 5mm
10:38 PM rue_shop1: 6mm...
10:39 PM aandrew: I'm going off of https://bricks.stackexchange.com/questions/2066/what-are-the-size-of-lego-technic-parts
10:39 PM rue_shop1: 7mm, 1/4"
10:40 PM aandrew: hm?
10:40 PM aandrew: that's getting pretty large, and I've already got the 3/16" rod in hand
10:40 PM rue_shop1: hmm I have a lot of 5mm
10:40 PM aandrew: just gotta hacksaw it a bit to make the right length
10:41 PM aandrew: holy crap it's late
10:41 PM aandrew: gotta take the youngest to an audition tomorrow
10:41 PM rue_shop1: huh
10:41 PM rue_shop1: nothing small enough
10:42 PM rue_shop1: aandrew, did you say you want this for the sliders?
10:42 PM rue_shop1: how far?
10:42 PM rue_shop1: like, how long of a side?
10:46 PM aandrew: About 150mm or so
10:55 PM rue_mohr: but...
10:55 PM rue_mohr: you cant get lego rods that long...
10:56 PM aandrew: Which is why I’m using the brass rod :-)
10:56 PM rue_mohr: the rod should prolly be steel
10:57 PM rue_mohr: but you dont want two confined bushings in parallel, it'll bind...
10:57 PM aandrew: You saw the video from before, just extended it
10:57 PM * rue_mohr ponders
10:57 PM aandrew: Yeah, that’s why I was looking at a bit of slop but the lego already gives that
10:57 PM rue_mohr: link me the video again?
10:58 PM rue_mohr: what resolution do you want to hit?
10:58 PM aandrew: The logo axles are too sloppy, but a tenth of a mm or so is better I think
10:58 PM aandrew: One moment
10:59 PM aandrew: https://youtu.be/HvsYecWLPYM
10:59 PM rue_mohr: whats the pitch of that leadscrew you have?
10:59 PM aandrew: The resolution is done via the time of flight sensor, it’s a closed loop system
11:00 PM aandrew: Standard m4 screw, what’s that, 0.5mm?
11:00 PM aandrew: Yep 0.5mm for fine thread
11:01 PM rue_mohr: so, you need more length?
11:02 PM aandrew: Yes. I made a longer leadscrew, and the brass rod is for the guides
11:03 PM rue_mohr: what if you move to smooth toppers and rectangular slides?
11:03 PM aandrew: That would also work
11:05 PM rue_mohr: it might be more accessable in the short term
11:06 PM rue_mohr: all i can offer you for the diection your working on is some 5mm bushings
11:06 PM rue_mohr: but I think that done like that, they would bind
11:06 PM rue_mohr: you want to mind parallal axies
11:06 PM rue_mohr: only one rail should constrain both axies
11:07 PM rue_mohr: the other(s) should float and only constrain in one
11:08 PM rue_mohr: 3d printers do it wrong
11:08 PM rue_mohr: I'v seen a few commercial projects that did too
11:08 PM rue_mohr: they wore out really badly
11:08 PM rue_mohr: http://ruemohr.org/~ircjunk/tempimage/p1180761.jpg
11:08 PM rue_mohr: so i redid mine
11:09 PM rue_mohr: the right rail is a full 2 axis grab, the left rail is can float left-right
11:09 PM rue_mohr: and just holds the table up
11:10 PM rue_mohr: so its impossable to bind
11:10 PM aandrew: Yeah I was getting binding with two rails, I thought maybe adding more would help prevent it from wobbling so much. It helps a little but not enough, I thought because still too much slop
11:10 PM rue_mohr: a larger square frame might play out better
11:11 PM aandrew: I can make one side float at one end easily enough I think
11:28 PM rue_mohr: wow youtube is crazy heavy on the ads
11:55 PM spline: it's horrid on mobile
11:55 PM spline: I run ublock and thankfully works on desktop