#robotics Logs

Jun 27 2020

05:01 AM rue_bed: probably clearance
06:42 AM Jak_o_Shadows: Hmm. Even though I have tidied my desk, the hexapod is still waiting on me to figure out how to drive a couple more servos
06:43 AM Jak_o_Shadows: My plan was to make little servo controller boards. Little 25 x 15mm PCBs to do the PWM for 3 servos
06:43 AM Jak_o_Shadows: Except I am waiting on the micros, and the caps
06:43 AM Jak_o_Shadows: and the voltage regulators
06:46 AM Jak_o_Shadows: That one is potentially stalled long enough to move into storage
07:01 AM rue_mohr: http://www.scorchworks.com/Injection_molding/injection_molding.html
07:23 AM Jak_o_Shadows: Oh, I like the one where the plastic is combined with the steel bearings
11:10 AM rue_mohr: hmm, upgraded the shop network and didn't get anymore speed, hmm
11:10 AM rue_mohr: but found out that one machine has a bad cable
11:11 AM rue_mohr: (and another had a connector not seated right)
12:47 PM mun: anyone know what the grey pump looking things are on this arm? https://images.3dmdb.com/1902912_preview.jpg
12:47 PM mun: are they springs? if so, what are their purpose?
12:52 PM rue_mohr: ugh, I need to put the rack on the truck again
12:52 PM rue_mohr: mun, yes
12:52 PM rue_mohr: they are pneumatic springs
12:52 PM rue_mohr: for balance
12:53 PM rue_mohr: see my small versions
12:53 PM rue_mohr: http://ruemohr.org/~ircjunk/robots/arm8/p1060649.jpg
12:53 PM mun: rue_mohr hmm but aren't they fixed to the upper arm? how would the springs be compressed/stretched?
12:54 PM rue_mohr: http://ruemohr.org/~ircjunk/robots/arm8/p1060648.jpg
12:54 PM rue_mohr: when the arm is staight up, they dont do much
12:54 PM rue_mohr: they apply more force as it comes down
12:55 PM rue_mohr: http://ruemohr.org/~ircjunk/robots/arm8/slide.htm
12:55 PM mun: rue_mohr hmm but when the upper arm comes down, how are the springs stretched? don't they just follow the upper arm down?
12:55 PM rue_mohr: look at the pictures
12:56 PM mun: oh, so they're mounted above the shoulder joint
12:56 PM rue_mohr: yes
12:57 PM rue_mohr: http://ruemohr.org/~ircjunk/robots/arm8/p1060646.jpg
12:57 PM mun: so they're there to help the arm stay straight
12:57 PM rue_mohr: http://ruemohr.org/~ircjunk/robots/arm8/p1060648.jpg
12:58 PM mun: nice
12:58 PM rue_mohr: that robot, with no motors, goes back to a neutral position
12:58 PM rue_mohr: the motors only have to move it out of that position
12:59 PM mun: right
01:00 PM mun: rue_mohr what are those blue sleeves over the springs?