#robotics Logs

Oct 27 2014

00:18 rue_house Tom_itx, ^^???
00:49 rue_house http://ruemohr.org/~ircjunk/robots/arm9/slide.htm <<-- I spruced up the slideshow page!
00:53 orlock hmm
00:53 orlock that plumbing fitting top/right corner of http://ruemohr.org/~ircjunk/robots/arm9/p1060745.jpg
00:54 orlock i think i used one of those as an adaptor to hold webcams
00:54 rue_house its a TA fitting that been cut down
00:54 rue_house its technically electrical
00:54 orlock the smooth side is a friction fit into a 50mm finder scope
00:54 orlock really? hmm
00:54 rue_house heh
00:54 orlock theres a plumbing fitting very similar
00:54 rue_house orlock, you dont like my slide show?
00:55 orlock i couldent click back or forwards!
00:55 rue_house the plumbing one is the same but for two differences, a) its not grey, b) its not CSA
00:55 rue_house wel duh, thats not working yet
00:55 orlock CSA? fireproof plastic?
00:55 rue_house no
00:55 rue_house its just electrically approved
00:55 rue_house its just pvc
00:56 rue_house ;) so is all the flat stuff, just pvc pipe
00:57 rue_house I should have flipped that last pulley over to the other side of the horn to tuck that all in closer to the robot
00:57 rue_house I wonder if there will be an arm10
00:57 rue_house these cost a lot to make tho
00:57 rue_house maybe I should see if they sell on ebay
00:57 rue_house its got to be almost $30 ea
00:59 rue_house $4 ea servo x5 + a $2.60 for the gripper, and the $2.70 controller, $1 or so for power connector, maybe $4 for servo cables...
00:59 rue_house there must be almost 25c in screws
00:59 rue_house oh, and those were the last of my bearings for the bases
01:04 rue_house think I should count how many peices that things made of?
01:04 rue_house I'm trying to keep the peice count down
01:04 rue_house esp the custom peice count
01:05 rue_house but I have a habbit of touching each part of the robot on my lathe
01:05 rue_house as you can maybe tell
01:07 rue_house huh, I changed directions a few times
01:07 rue_house on things
01:33 rue_bed-aok I'd like the next one to be completely cable driven,
01:33 rue_bed-aok if I can master driving with mostly cables, I'm ready to mix with air muscles
02:15 mrdata how big would a very large stirling cryocooler be? i'm thinking 1 MW heat to be removed
02:16 mrdata this will be used to condense 25 kg/s of N2 gas to liquid
09:18 rue_house never heard of that
09:18 rue_house hows that different from normal refrig?
10:15 mrdata a cryocooler is very efficient, apparently
10:16 mrdata https://www.youtube.com/watch?v=GqIapDKtvzc
10:17 mrdata https://www.youtube.com/watch?v=GFfMruoRMGo
10:18 mrdata parts 1 and 2 fully explain the stirling engine including its use as a cryocooler
10:22 mrdata the thermal efficiency of the cycle approaches the limiting Carnot efficiency
10:22 MjrTom it can be whatever size you want, as you've left the time frame you're looking for open ended
10:22 MjrTom the cooling is over time
10:23 mrdata no, i have not left it open
10:23 MjrTom did I miss soemthing...
10:23 MjrTom oh I did
10:23 mrdata if you read carefully, i'm asking for 1 MW which is 1 million joules every second
10:23 MjrTom thats a lot
10:23 mrdata indeed
10:24 mrdata altho i did miscalculate the mass of the liquid N2; should be 5 kg/s to condense
10:25 MjrTom thats still quite a lot but a lot more manageable
10:25 mrdata i am wondering if thats house sized, or can be smaller
10:26 MjrTom at a guess, for that rate, I'd suppose a large room... something like bedroom sized
10:39 MjrTom BTW, what do you want some 5 kg/s of N liquid for mrdata?
10:41 mrdata i must keep my hoverboard cool
10:41 mrdata ;)
10:41 mrdata the liquid N2 will keep a YBCO superconductor cold
11:10 MjrTom sounds like an indiegogo
16:47 ganzuul ah... mrdata already left
16:47 ganzuul http://en.wikipedia.org/wiki/SABRE_%28rocket_engine%29
16:55 ace4016 hehe, that's very relevant to his convo earlier
16:56 ace4016 "lets stick a large cryocooler to cool the incoming air!"
17:06 ganzuul Yeah. Can be done. While airborne, even.
17:09 Terrenkt they've done ground prooftests of the cooler, I ahven't heard any news about tests at altitude
17:59 ganzuul hmm... Assuming it isn't a broken design
19:17 ganzuul I want a massage bot.
19:17 ganzuul For my shoulders.
23:46 rue_shop3 power outage!