#robotics Logs

Apr 17 2018

12:41 AM rue_mohr: http://imperiya.by/image/lZjMqlUJXIx.jpg
12:44 AM rue_mohr: hmm
12:44 AM rue_mohr: can you spot what broken?
12:48 AM rue_mohr: https://i.ytimg.com/vi/e-AClwxINBU/maxresdefault.jpg
12:48 AM rue_mohr: *click* I get it
12:49 AM zhanx: who made that?
12:49 AM rue_mohr: dunno, dont care, I get it!
12:50 AM zhanx: second link is weird
12:54 AM rue_mohr: https://image.slidesharecdn.com/0603portfolio-12781964783238-phpapp01/95/animatronics-portfolio-17-728.jpg?cb=1278178806
12:54 AM rue_mohr: hmm
02:27 AM Jak_o_Shadows: Where's the sense wires on those pistons?
02:27 AM Jak_o_Shadows: like, do they bother controlling the piston positin?
02:27 AM Jak_o_Shadows: Or have they shoved position control down the chain to the fingers?
05:33 AM z64555: position sensing might be from the pressure difference on the "unpowered" side... but uh. I don't think that's a great of an idea
05:35 AM z64555: another issue may be with the pivots not linging up. IIRC human joints don't have a stationary pivot like most machines do
05:37 AM theBear: various joints around the body are all kinds of different approaches... some slightly different, or perhaps only different in 1 or 2 dimensions, roughly, cos ya know, bodies ain
05:37 AM theBear: 't all nice right angles and such
05:47 AM SpeedEvil: Also, changing joint angles and such just changes gait and stuff,doesn't mean you can't do a task
05:48 AM SpeedEvil: https://www.youtube.com/watch?v=pgaEE27nsQw - relevant
05:48 AM SpeedEvil: Flexible Muscle-Based Locomotion for Bipedal Creatures
05:48 AM SpeedEvil: Optiising muscle attachment at the same time as evolving gaits.
05:53 AM theBear: changing hinge angles changes gate
05:53 AM theBear: angles
05:53 AM theBear: <grin>
05:54 AM * theBear imagines a pair of big muscled arms pistoning back and forth turning the wheels on the front carriage of a train
05:54 AM theBear: mmm, flexible muscle-based locomotion, oh, that's not bipedal
05:55 AM theBear: ooh, pushbike kinda is, mmm, but a pushbike isn't called a locomotive <sigh> man, life can be hard some days
05:55 AM theBear: heh
12:18 PM z64555: Anybody know enough about the materials science of glass to tell what failed here? https://i.imgur.com/HsGNIK0.jpg
12:20 PM z64555: or maybe enough about mechnical engineering (statics)
12:21 PM Tom_L: it was an oopsie
12:21 PM z64555: I'm thinking the legs had too-little contact surface with the glass, and created enough torque at the corner to break the glass's surface tension
12:21 PM durrf: ur shits fucked
12:21 PM durrf: thats what happened
12:21 PM z64555: aside from the obvious (also not my desk)
12:22 PM Tom_L: hard to say what outside force affected it
12:22 PM Tom_L: it was tempered
12:23 PM Tom_L: maybe jayson borne jumped on it
12:24 PM z64555: Note that there's just legs, there isn't any framing members to distribute pressure around the edge
12:24 PM Tom_L: who's table was it?
12:25 PM z64555: not sure, somebody in another IRC channel shared it
12:25 PM z64555: Asked about it, and he said he got it from a reddit
12:25 PM Tom_L: for all i know somebody could have shot at it
12:26 PM Tom_L: center punch is just as effective
12:32 PM z64555: https://www.reddit.com/r/pcmasterrace/comments/8cvrrz/rate_his_se_never_mind/
12:32 PM z64555: one theory is sunlight exposure weakened the glass
12:33 PM Tom_L: it's transparent so it shouldn't heat much but if it heated unevenly as in the sunrise etc it could cause thermal stress
12:34 PM Tom_L: i think anyone with a glass table is foolish anyway
12:36 PM z64555: They're OK as long as you don't put anything on them
08:08 PM rue_mohr: my 80V solinoid driver dosn't work
08:20 PM SpeedEvil is now known as Guest42653
10:15 PM LuminaxWork is now known as LuminaxWk
11:25 PM BitEvil is now known as SpeedEvil