#robotics Logs

Jun 20 2021

05:09 PM rue_shop2: ok I need to get a rotation sensor on my tilt and pan mirror
05:16 PM rue_shop2: I think the idea is to use a 10 turn pot under some weatherproofing, but I'm not sure on good belt to use for the outdoorsness
05:16 PM rue_shop2: maybe I can just add something to the gearbox and wrap it all
09:41 PM rue_mohr: z axis for my cnc
09:43 PM Tom_L: let's see
09:43 PM rue_mohr: no I mean I need to work on that
09:44 PM rue_mohr: I'm having an awefull time getting things happening
09:47 PM Tom_L: you did 5 castings... that's something
09:47 PM Tom_L: more than i did today
09:50 PM rue_mohr: meh
09:50 PM rue_mohr: I want to try a lost pla casting
09:50 PM rue_mohr: someone pointed me to a youtube video that was interesting
09:50 PM Tom_L: how does that work?
09:51 PM rue_mohr: apparently if you print light, cover it in plaster, and sand back it, you can get really good castings
09:51 PM rue_mohr: "lots of aluminum flow"
09:51 PM rue_mohr: I'm quite skeptical
09:52 PM Tom_L: was your sand too dry on the other parts?
09:52 PM Tom_L: or just the lack of relief
09:52 PM rue_mohr: or too roungh a print?
09:52 PM rue_mohr: I could try things again, there is just more to try, is all
09:53 PM Tom_L: the guy in #linuxcnc smooths his parts out before he gives them to the foundry
09:53 PM Tom_L: he's done several
09:53 PM rue_mohr: I'm suspicious because the plaster backing had bad results
09:53 PM rue_mohr: the plaster doesn't breathe, so gasses cant get out
09:53 PM Tom_L: it should be something that will stick to the pla
09:53 PM rue_mohr: and they split on me when I did them
09:54 PM rue_mohr: the sand backing relaxes the requirements
09:54 PM Tom_L: oh you mean using it as part of the casting
09:54 PM Tom_L: you probably have to low temp bake it first
09:54 PM Tom_L: remove all the moisture
09:55 PM rue_mohr: not sure, but the sulphor in the plaster is also an issue
09:55 PM rue_mohr: and cracking when it sets
09:59 PM Tom_L: oh
10:00 PM Tom_L: gonna be a bad night
10:00 PM Tom_L: ate some bad food i think
10:00 PM rue_mohr: oh hno
10:01 PM rue_mohr: https://www.youtube.com/watch?v=pyZEJRet_8o&feature=emb_logo
10:02 PM rue_mohr: thats the video, I'm focusing on how it was made, not what it was
10:07 PM Tom_L: trying to order these cuts to minimize tool changes
10:08 PM rue_mohr: ;) you just need a tool changer :)
10:08 PM Tom_L: no money for that
10:10 PM Tom_L: that's just like that 'how it's made
10:10 PM Tom_L: video i showed you a while back
10:10 PM rue_mohr: I think there are a lot of hidden errors and issues
10:11 PM Tom_L: you could use a pot like his
10:12 PM Tom_L: latel
10:12 PM rue_mohr: $$
10:12 PM Tom_L: i know
10:12 PM rue_mohr: about $200 usd
10:12 PM rue_mohr: WAY too much for me
10:12 PM Tom_L: yeah
10:12 PM rue_mohr: I put a LOT of effort into some instructable contests with amazon card prizes and didn't even get mention
10:13 PM rue_mohr: people aren't interested int the stuff I do
10:13 PM Tom_L: a few of us are
10:13 PM Tom_L: but yeah today most ppl want it handed to em
10:14 PM Tom_L: that plastic made the aluminum bubble too much
10:14 PM Tom_L: looked kinda dangerous
10:14 PM Tom_L: but he did get a result
10:14 PM rue_mohr: that second one with the pot over it wasn't sufficiently vented
10:15 PM rue_mohr: yea, I'm wondering if it was really that good
10:15 PM Tom_L: well hell yeah... you just saw it!
10:15 PM rue_mohr: heh
10:15 PM Tom_L: i know in industry that lost wax casting is more accurate
10:16 PM rue_mohr: yea, I did some setup for lost wax
10:16 PM rue_mohr: but I need to make a wax printer
10:16 PM rue_mohr: its called "GooSage" and its on the livingroom floor
10:16 PM rue_mohr: its not calibrated or anything
10:17 PM Tom_L: https://www.youtube.com/watch?v=GWVli5iY8BI
10:17 PM Tom_L: not the same one
10:18 PM Tom_L: https://www.youtube.com/watch?v=AfNrMrP6Wr8
10:18 PM rue_mohr: watching it again, there are a lot of spots where the plastic didn't completely burn out
10:18 PM Tom_L: i think that's the one
10:20 PM Tom_L: but they use wax
10:21 PM rue_mohr: omg he just tips the whole electric kiln
10:23 PM Tom_L: https://all3dp.com/2/lost-pla-casting-guide/
10:27 PM Tom_L: maybe something there
10:29 PM rue_mohr: yea that plaster and showered in sand thing
10:30 PM rue_mohr: that last site wont let me in
10:30 PM rue_mohr: it cant load the 3rd party ads
10:31 PM Tom_L: use an ad blocker, i do
10:31 PM Tom_L: https://twitter.com/RueNahcMohr/status/1231733855423348736
10:31 PM Tom_L: :)
10:31 PM rue_mohr: yea it cant tell I have one and wont let me in
10:32 PM Tom_L: ublock origin lets me in with no ads
10:32 PM rue_mohr: heh
10:33 PM Tom_L: looked like maybe some good info if you can find a way in
10:33 PM rue_mohr: it says I'v done almost 24k tweets
10:33 PM rue_mohr: I suspect I'm running out of things to talk about
10:33 PM rue_mohr: but yea, thats goosage
10:34 PM Tom_L: i think i saw it when you did it
10:36 PM rue_mohr: I'm wondering if I'v spread myself out too much
10:36 PM rue_mohr: the byte is tooooo big to choooo
10:36 PM rue_mohr: I need to figure out my z axis
10:37 PM Tom_L: you've never been accused of that!
10:37 PM Tom_L: i picked cnc over electronics
10:37 PM Tom_L: only so much time
10:56 PM rue_shop2: I think I'm wearing out the sherline
10:57 PM rue_shop2: there is about another 1L of shavings to clean out of it
10:57 PM Tom_L: hah
10:57 PM rue_shop2: you know, at some point I tried to move into the bedroom more, and its a thing I need to reverse
10:57 PM Tom_L: what parts you cuttin on it?
10:57 PM rue_shop2: need to spend more time on the shop
10:58 PM rue_shop2: well, almost everything at this point
10:58 PM rue_shop2: better motor for handling the 1/8" bit
10:58 PM Tom_L: the sherline doesn't handle that?
10:58 PM rue_shop2: but there were a few times we were looking at the cuts thinking ????
10:58 PM rue_shop2: yea, my other one just has a small motor at 1:1
10:58 PM Tom_L: ahh ok
11:00 PM Tom_L: what's your purpose for building the large one?
11:01 PM rue_shop2: I need to be able to cut bigger stuff
11:02 PM rue_shop2: the machines are always a bit too small
11:02 PM rue_shop2: so, just dial it to max
11:02 PM rue_shop2: 4'x8'
11:02 PM rue_shop2: if I need larger than that there is a problem
11:09 PM Tom_L: big jump from a sherline to 4 x 8