#garfield Logs

Aug 13 2021

12:27 AM rue_mohr: ok, how small can oshpark make a via
12:37 AM aandrew: rue_mohr: 10mil
12:37 AM aandrew: https://docs.oshpark.com/submitting-orders/drill-specs/
12:37 AM rue_mohr: found it
12:37 AM rue_mohr: now I'm having an issue using it because kicad is snapping to places I dont want it
12:37 AM aandrew: rue_mohr: you building and underground bunker like that UK dude?
12:38 AM rue_mohr: ah I can move it ok
12:38 AM rue_mohr: aandrew, we will see
12:38 AM rue_mohr: if nothing else, its good for a well
12:38 AM aandrew: rue_mohr: you're gonna need REALLY good drainage
12:41 AM rue_mohr: it wont let me wire the via becuase it thinks it conflicts with the traces I'm trying to attach it to
12:41 AM rue_mohr: Kicad needs to be stupider
12:42 AM aandrew: is the via actually connected to the same net?
12:42 AM aandrew: I have that happen in altium occasionally
12:42 AM rue_mohr: it was a new via
12:42 AM aandrew: yeah
12:42 AM aandrew: in altium you double click and assign it to the net you want
12:42 AM aandrew: because the default is no net
12:43 AM rue_mohr: double..???
12:43 AM rue_mohr: !! ok!
12:43 AM aandrew: rue_mohr: in altium, not sure how you assign a net to an arbitrary PCB object in Kicad
12:43 AM rue_mohr: double click brings it up
12:56 AM aandrew: was that the issue?
12:58 AM rue_mohr: its having challanges with the ratnest and me bringing up a node from the bottom layer
12:58 AM rue_mohr: I'll beat on it with a hammer
01:01 AM rue_mohr: its like it should be possible to constrain the ratnest to a layer
01:03 AM rue_mohr: ok, I think its got it
01:04 AM rue_mohr: I can link one of the other gclk lines to an adjacent IO line, I'm thinking that could be handy
01:28 AM rue_mohr: oh it looks like a flood doesn't count as a trace
01:42 AM rue_mohr: yea the kicad ratnest isn't layer-aware
01:42 AM rue_mohr: but the 3d view realtime updates
02:02 AM rue_mohr: done?
02:07 AM rue_mohr: silk screen adjustments is all thats left I think
02:21 AM rue_mohr: *sigh* I'm gonna end up combing traces for days
02:21 AM rue_mohr: oh well
03:56 AM Tom_L: no erc or drc in kicad?
08:30 AM rue_bed2: sure, but I'm doing asthetic adjustments
11:49 AM aandrew: wtf
11:49 AM aandrew: three LDOs (TPS799xx), all fed from 3.3V, all regulating low
11:50 AM aandrew: 2.8V is at 2.0V, 1.8V is at 1.4V and 1.2V is at 1V
11:50 AM aandrew: board is clean, no shorts, nothing getting warm
07:30 PM rue_mohr: dropout isn't low enough?
08:08 PM Tom_L: how do i remove a program from rpi4? it's been way too long....
08:10 PM rue_mohr: apt-get remove
08:10 PM rue_mohr: I think
08:10 PM rue_mohr: or
08:10 PM rue_mohr: if you like
08:10 PM rue_mohr: apt-get purge
08:11 PM rue_mohr: ok I hooked gclk 3 to an adjacent io pin
08:11 PM rue_mohr: that should help get around clock domains
08:11 PM Tom_L: i think i got it
08:11 PM Tom_L: i used the gui
08:11 PM rue_mohr: gui?
08:11 PM Tom_L: their front end
08:11 PM rue_mohr: crap
08:11 PM rue_mohr: damnit
08:12 PM rue_mohr: today was another all out run-around day
08:12 PM rue_mohr: am I way to freaking late to try to organize shipping for the clad?
08:12 PM Tom_L: i had a pre release of linuxcnc and i need to get rid of it so i can install the final one
08:12 PM rue_mohr: 8-|
08:12 PM Tom_L: but it is friday
08:13 PM rue_mohr: we did a fire inspection that we were trying to keep to about 4 hours cause of the horrid heatwave
08:13 PM rue_mohr: and at the end of an 8 hour day, it pulled a fault
08:13 PM Tom_L: great
08:13 PM rue_mohr: didn't take tooo long to work out, but I cant keep my head screwed on enough to rememeber anyhing
08:14 PM Tom_L: join the club
08:15 PM rue_mohr: I have one gpio pin I can still use for something on the cpld board
08:15 PM Tom_L: blinky led
08:15 PM Tom_L: :)
08:15 PM rue_mohr: ran out of room for buttons and leds ;)
08:15 PM rue_mohr: its quite a busy board
08:43 PM Tom_L: ok, transferred my mill configs to the rpi and updated it to the latest 2.8.2-21 .deb
09:13 PM aandrew: Any rain in sight, rue_mohr?
09:20 PM rue_shop3: turning the holders
09:20 PM rue_shop3: 0.55mm
09:20 PM rue_shop3: how much is an interfearance fit usually?
09:22 PM Tom_L: .0005" for sure likely a little more than that
09:23 PM Tom_L: it depends on the diameter of the fit also
09:24 PM Tom_L: turning which holders?
09:24 PM aandrew: https://imgur.com/gallery/5xmhXea made me LOL
09:24 PM rue_shop3: those bearing blocks we did
09:25 PM Tom_L: you want a press fit?
09:25 PM rue_shop3: yea
09:25 PM rue_shop3: what do you think
09:25 PM rue_shop3: I was gonna try 15thou
09:25 PM rue_shop3: sounds waaay too much
09:25 PM Tom_L: you could go .001 - .002 under and use heat
09:25 PM Tom_L: that's too much
09:25 PM rue_shop3: ok
09:25 PM rue_shop3: I'll shoot 1 thou
09:26 PM rue_shop3: 0.03mm
09:26 PM Tom_L: 15 would stress the bearing too much even if you could get it in
09:26 PM Tom_L: you could try 2 and see if you can heat/freeze it in
09:28 PM Tom_L: https://www.tstar.com/blog/bearing-selection-and-achieving-the-right-press-fit
09:28 PM Tom_L: The example below features an example of a press fit utilizing a housing bore of 0.5934/0.5941,” shaft 0.499/0.498 with the temperature varying from 68 deg. F to 200 deg. F.”
09:29 PM Tom_L: that seems like alot to me
09:29 PM Tom_L: but a wide temp range
09:30 PM rue_shop3: oops, 1 thou turned into 0
09:30 PM Tom_L: they're discussing plastic
09:30 PM rue_shop3: guess that one gets glue
09:30 PM Tom_L: shim stock
09:30 PM Tom_L: as you press it in
09:31 PM Tom_L: Brieschke says a 2-inch-diameter bearing that is pressed onto a metal shaft, for example, could have a tolerance range of 0.001 to 0.01 inch due to the larger relative diameter of the two pieces.
09:32 PM Tom_L: so .001 is on the low end
09:32 PM Tom_L: .010 still seems like alot
09:32 PM rue_shop3: hmm
09:32 PM Tom_L: i'd aim for .002 and see
09:33 PM rue_shop3: hmm
09:34 PM Tom_L: or a bit more, you can always remove more
09:34 PM Tom_L: that size, the aluminum will probaby expand the full .010 but you have little working time
09:35 PM Tom_L: dry ice and an oven
09:39 PM rue_shop3: small peice of 6 thou brass shim stock
09:39 PM rue_shop3: 8} we will see!
09:39 PM rue_shop3: (its togethor)
09:45 PM Tom_L: pics
09:46 PM rue_mohr: arg how rude of me!
09:46 PM rue_mohr: http://ruemohr.org/~ircjunk/tempimage/p1200621.jpg
09:46 PM rue_mohr: http://ruemohr.org/~ircjunk/tempimage/p1200622.jpg
09:47 PM Tom_L: nice
09:47 PM rue_mohr: yea, I have to drill the mouning holes, but how hard could that be!
09:47 PM rue_mohr: thats 1/4
09:47 PM Tom_L: it's hard to give a solid answer on press fit because of sized and what bearings are made to take as far as fit
09:48 PM Tom_L: cnc the holes so they're all the same
09:48 PM rue_mohr: yep
09:48 PM rue_mohr: if I could cnc, I'd castelate it
09:48 PM Tom_L: well make a template you can transfer from one to the next and drill from the bottom
09:49 PM Tom_L: plate with 2 holes clamped to them
09:49 PM rue_mohr: they dont really have to be the same either
09:49 PM rue_mohr: but yep
09:49 PM rue_mohr: plate with pilot holes
09:49 PM Tom_L: drill one, and pin it then drill the other
09:49 PM rue_mohr: heh, I definitly dont have to be that close
09:50 PM Tom_L: broken drills/cutters make good pins
09:50 PM rue_mohr: ok
09:50 PM Tom_L: easy way to be accurate on a press though
09:55 PM Tom_L: you got a nice size lathe
09:57 PM rue_shop3: I'd have bigger and older if I could
10:07 PM rue_bed2: ok need nap
10:07 PM rue_bed2: I'll stay up at night while its cooler
10:09 PM Tom_L: :/
10:09 PM Tom_L: it cooled off here overnite
10:09 PM Tom_L: rained and wasn't so bad today