#robotics Logs

Aug 06 2014

00:00 GuShH they are a compromise.
00:00 GuShH I mostly deal with aluminum and brass, so I might tune it for that, but I do cut steel.... (ideally you would have two machines, one for ferrous one for non ferrous) but hey that's expensive.
00:01 ShH was just testing the temporary depth stop, was able to cut 20 pieces of the same length very quickly with
00:02 GuShH it looks like one of those old indicator stands, just two blocks, pass-through hole and a blind hole on the other end, with set screws and 1/2" round stock going through.
00:02 rue_mohr2 I'm pondering a tiny13 for power supply control
00:02 rue_mohr2 this is bad
00:02 rue_mohr2 differential adc -> pwm
00:02 GuShH I'm getting a lot more straight cuts than the guys at the shop get with their 10k machine, but they've pushed that thing way too much and it needs refurbishing I think
00:02 rue_mohr2 tight loop
00:02 rue_mohr2 if it can update the pwm register at the same speed as the pwm cycle, whats the diff?
00:03 GuShH Hyratel1: one problem with horizontal bandsaws is rigidity of the "arm" the more you push on it the more it'll flex and the blade will deviate to the side...
00:03 Hyratel1 so a low cutting pressure is key?
00:03 GuShH by push I mean the down force, but you can actually push it with your hands if you wanted to...
00:04 GuShH depends on the tension of the blade
00:04 GuShH but that's what I keep seeing, it tends to cut slightly off, even if it's well tuned and a very expensive machine, wear is wear.
00:07 rue_mohr2 yay the cat came home!
00:07 GuShH shop cat!
00:07 GuShH or house cat?
00:07 rue_mohr2 house cat
00:08 rue_mohr2 the horizontal cuts fine if the blade isn't dull
00:08 rue_mohr2 the duller it is, the more angle it puts on the cut
00:08 rue_mohr2 to the point where I offset the material about 13 degrees to get a straight cut
00:08 GuShH rue_mohr2: it wasn't dull
00:08 rue_mohr2 I cut things I shouldn't with mine
00:08 GuShH the guy was in a very nice mood, so I was able to fool around with the machines while I waited for the cuts
00:09 rue_mohr2 like $500 surge suppressor modules
00:09 GuShH lol
00:09 rue_mohr2 it was potted, I didn't learn much :(
00:10 GuShH haha
00:10 GuShH only that it makes a mess
00:10 rue_mohr2 mauled the blade too
00:10 rue_mohr2 there is a brief reference to using the 3842 for a buck converter
00:11 rue_mohr2 says I need to find the "unitrode applications handbook"
00:12 rue_mohr2 I cant help but feel they didn't try to save my dad
00:12 rue_mohr2 what happened to organ transplants from pigs?
00:13 rue_mohr2 "were going to harvest your organs, but its ok, after that we will make bacon out of you"
00:19 Hyratel1 rue_mohr2, if you're cutting through potting compound, use lots of coolant and a slow blade speed. it melts something fierce
00:19 rue_mohr2 even if its poly resin?
00:20 rue_mohr2 my bandsaw has 1 speed
00:20 rue_mohr2 no, two
00:20 rue_mohr2 on and off
14:25 i-make-robots updated my open source crab simulation to run in Java. https://www.marginallyclever.com/blog/2014/08/open-source-hexapod-crab-robot-simulator/
14:25 i-make-robots i hope that helps some of you with your inverse kinematics
14:34 deshipu nice
14:34 shipu l
14:34 deshipu crabs have 10 legs, no?
15:13 i-make-robots deshipu - depends who you ask. my gf named the robot spidee. clearly the wrong number of legs!
15:13 i-make-robots I would call it a hexapod but that gets confusing when I also make stewart platforms.
15:43 deshipu i-make-robots: well, I make quadrupeds, but base their looks on the jumping spiders
15:44 deshipu i-make-robots: so I totally understand
15:44 deshipu i-make-robots: nature somehow can pack much more legs into a tighter design
16:09 Hyratel1 deshipu, well muscles have a higher mechanical work density
16:09 Hyratel1 and aren't limited to standard form factors
16:16 deshipu many arthropods are actually half hydraulic
16:17 deshipu they bend legs with muscles, but straighten them with fluid
16:17 deshipu that's why spiders have to "rest" every several cm, to rebuild internal pressure
16:18 deshipu I suppose one could put all the servos/whatever indside the body, and use pushrods for everything
16:19 deshipu should be fine for 3dof legs
16:19 deshipu but calculating the ik would be hard
16:42 Tom_itx rue_mohr2, http://www.electronicproducts.com/Digital_ICs/Video_Graphics_Audio/How_to_turn_your_living_room_wall_into_an_80_inch_touchscreen_for_less_than_500.aspx
23:14 rue_mohr2 when am I gonna get the sketch for that quadroped!?
23:16 rue_mohr2 Tom_itx, so its not real yet? but its already been done!
23:16 rue_mohr2 !?!?!
23:17 GargantuaSauce http://a.pomf.se/kecnhj.webm
23:31 rue_mohr2 ist spek nin deutch!
23:33 rue_mohr2 I had popcorn for supper, should I hit or fold?
23:34 Tom_itx nutritious
23:35 rue_mohr2 I have a script that opens me 20 terminal windows
23:35 rue_mohr2 I hate it when I end up getting them all doing the same thing
23:35 rue_mohr2 one by one they all end up logged into antoher machine, or in the /files/temp dir, or something stupid
23:36 Tom_itx heh
23:36 i-make-robots rue_mohr2 - double down?
23:36 i-make-robots no! bluff!
23:37 rue_mohr2 I'm bluffing now, I think I need more cards
23:37 i-make-robots emacs --something-stupid is my favorite editor.
23:37 Tom_itx what's missing when a script won't run?
23:37 make-robots gives you a get out of jail and an uno
23:37 rue_mohr2 commenting out the exit at the top of it
23:37 i-make-robots Tom_itx - the interpreter?
23:37 i-make-robots legs!
23:37 i-make-robots it's missing legs.
23:38 Tom_itx i'll tackle it tomorrow...
23:38 Tom_itx trying to build some source files
23:38 i-make-robots so it seems all my robots have either (a) acceleration profiles but no look-ahead or (b) constant speed and lots of look-ahead.
23:39 i-make-robots the best of both worlds is a LOT of work but I should only have to solve it once for all robots.
23:41 rue_mohr2 why does ekg use 10 electrodes?
23:43 rue_mohr2 I lost my EKG trace, i was surprised by the signal strength, it was like 2mv
23:46 rue_mohr2 and I seriously need a browser that can handle me having 200 tabs open
23:47 GargantuaSauce opera
23:48 GargantuaSauce the catch is some websites' javascript doesnt work well in it, and it runs flash in the same process as the other stuff so flash breaking can screw the whole browser
23:48 GargantuaSauce so i use both it and chromium
23:49 rue_mohr2 yea, I want a "terminate page loading after X seconds"