#garfield Logs

Sep 26 2022

12:30 AM rue_mohr: modifying a power supply to drive the motors
06:53 AM polprog: I passed my state driving licence test!
07:08 AM Tom_L: watch out world
10:41 AM rue_mohr: I'm awake again, I think its going to stick
02:19 PM polprog: rue_mohr: i was thinking about your eprom function tweet
02:19 PM polprog: i meant that without a jump you cant make a real CPU
02:20 PM rue_mohr: oh its for a cpu system
02:20 PM rue_mohr: like a z80 system
02:20 PM polprog: ohh
02:20 PM rue_mohr: so it can do lookups
02:20 PM polprog: so like a fast coprocessor
02:20 PM polprog: Yeah thats awesome
02:20 PM rue_mohr: :) for things like toupper()
02:21 PM polprog: you could for example implement the u-law codec
02:21 PM rue_mohr: totally
02:21 PM polprog: that works on 8 bit integers
02:22 PM polprog: and the maths to do it in asm is hard
08:23 PM rue_mohr: Tom_L, so I cast 2 blanks
08:23 PM rue_mohr: the second one boofed
08:24 PM rue_mohr: I should have given it more risers, and poured it hotter and faster
08:24 PM rue_mohr: http://ruemohr.org/~ircjunk/tempimage/p1250832.jpg
08:24 PM rue_mohr: http://ruemohr.org/~ircjunk/tempimage/p1250833.jpg
08:24 PM rue_mohr: http://ruemohr.org/~ircjunk/tempimage/p1250834.jpg
08:24 PM rue_mohr: the first one came out good tho
08:24 PM rue_mohr: http://ruemohr.org/~ircjunk/tempimage/p1250824.jpg
08:27 PM Tom_L: looks good
08:28 PM rue_mohr: the first images of the 2nd casting were totally borked
08:29 PM rue_mohr: it didn't fill and shrunk
08:29 PM rue_mohr: I might be able to use it, but I'm gonna cast up a stock of a few
08:29 PM rue_mohr: the first one came out great
08:29 PM rue_mohr: each of them have needed to be molded twice to get a good mold
08:31 PM rue_mohr: huh 2817
08:31 PM rue_mohr: its just going up
09:12 PM Tom_L: you use the same print for all?
09:12 PM rue_mohr: yup
09:12 PM rue_mohr: I think it needed a bit more slope
09:12 PM Tom_L: wax it or any prep?
09:12 PM rue_mohr: baby powder, but thats a good point
09:12 PM Tom_L: what angle did you use?
09:13 PM rue_mohr: 1.5mm over 20mm
09:13 PM rue_mohr: I cut it with a cone that was 3mm at the base, 0 at the tip, and 20mm long
09:15 PM Tom_L: 4.2 deg
09:15 PM Tom_L: 4.3
09:15 PM rue_mohr: oh thats better than I thoguht
09:15 PM rue_mohr: thats close to recommended isn't it?
09:15 PM Tom_L: i'm not sure but it seems like that's kinda midrange
09:16 PM rue_mohr: I think you used more than that on the box and it came out good
09:16 PM Tom_L: For standard aluminum castings, engineers will incorporate ± 1-2° of draft angle to accommodate for the abrasive nature of the metal. For zinc castings, the standard for draft angles is 0.5°.
09:16 PM rue_mohr: oh cool
09:17 PM rue_mohr: so, my ability to mold it up just sucks a bit :)
09:17 PM Tom_L: wax it
09:17 PM Tom_L: or smooth it out somehow
09:17 PM rue_mohr: yep
09:17 PM Tom_L: paraphin? wax
09:17 PM Tom_L: drip some on and spread it out
09:18 PM rue_mohr: oh I have a bunch for making machinsts was
09:18 PM rue_mohr: I think I had to kinda heat gun it a bit to get it to spread
09:18 PM rue_mohr: carefully cause the 3d prints are really light
09:18 PM Tom_L: unless that would mix with anything in the sand (oil)
09:18 PM Tom_L: i dunno
09:18 PM rue_mohr: I used like 2 shell laters and 10% infill
09:18 PM Tom_L: something that the 2 don't like each other
09:19 PM rue_mohr: my sand is water base
09:20 PM rue_mohr: oh I better look at the calandar and see what I was SUPPOSED to have done
09:20 PM Tom_L: get a job
09:20 PM Tom_L: my kid gave notice today
09:20 PM Tom_L: he wasn't sure if they'd take it or walk him out
09:21 PM Tom_L: they need ppl so they'll keep him as long as they can
09:21 PM Tom_L: movin on.. $6 more/hr same job
09:32 PM rue_mohr: nice
09:32 PM rue_mohr: yep
09:32 PM rue_mohr: mm I missed listing things online for sale and working on the resume
09:32 PM Tom_L: so what's gonna come of the shed you built?
09:39 PM rue_shop3: I was trying to keep these kinda low so they dont look too tower-ie
09:39 PM rue_shop3: I learned that 10' is the max for moving on the local flatbeds
09:39 PM rue_shop3: as the beds sit about 3', and its about 13' to the wires
09:40 PM Tom_L: i took the roof off when we moved it after i built my garage
09:40 PM rue_shop3: yep
09:40 PM rue_shop3: I skipped the modularity on this one
09:44 PM Tom_L: that must have been a full pot of aluminum for that pulley
09:49 PM rue_mohr: I accidently used the small pot, filled it right up and it was ok
09:51 PM rue_mohr: here are some better images of the pullies, the one on the left was the first one
09:51 PM rue_mohr: http://ruemohr.org/~ircjunk/tempimage/p1250835.jpg
09:51 PM rue_mohr: http://ruemohr.org/~ircjunk/tempimage/p1250836.jpg
09:52 PM rue_mohr: I'm going to cast the next one upside down
09:52 PM rue_mohr: https://twitter.com/RueNahcMohr/status/1574488054689337344
09:52 PM rue_mohr: not a really big pot
09:54 PM rue_mohr: I also ran out of baby powder