#robotics Logs

Jun 16 2019

01:20 AM Jak_o_Shadows: ok, torque calculation formula done.
01:24 AM Jak_o_Shadows: so 10N load axially requires 154Nmm torque
01:24 AM rue_mohr: which method did you use?
01:26 AM Jak_o_Shadows: method? This is for a stewart platform
01:27 AM mrdata: 10 N load, 154 Nmm torque -> 15.4 mm lever
01:27 AM Jak_o_Shadows: look, i am going to go and change it all to metres
01:28 AM mrdata: fine. 0.0154 m
01:33 AM Jak_o_Shadows: yeah, so I am now getting 0.154 Nm per motor
01:33 AM Jak_o_Shadows: and I have 6
01:33 AM Jak_o_Shadows: The lever is 0.1m
01:33 AM Jak_o_Shadows: The force on each virtual leg (not the lever leg, or the upper leg) is 1.74Nm
01:33 AM mrdata: hmm... https://en.wikipedia.org/wiki/Stewart_platform
01:34 AM zhanx: i am gonna do the first test frame in it
01:35 AM Jak_o_Shadows: http://pasteall.org/pic/show.php?id=3c69570ee97fcae68d26d6e22731faf0
01:35 AM Jak_o_Shadows: The lever arms are in red
01:35 AM Jak_o_Shadows: I have a 10NM torque (upwards I think)
01:37 AM Jak_o_Shadows: sorry, 10NM force
01:37 AM Jak_o_Shadows: 10N
01:42 AM Jak_o_Shadows: But anyway, say I want 5kg. So that's nearly 50N. and I want that more in shear
01:46 AM Jak_o_Shadows: hmm. with 10kg.cm servos, I can do 1kg pure shear force
01:46 AM Jak_o_Shadows: with this leg configuration anyway
04:06 AM mrdata is now known as mrdata-
04:16 AM mrdata- is now known as mrdata
04:20 AM mrdata is now known as mrdata-
06:35 AM Jak_o_Shadows: huh, was doing torques wrong, but at least it was an ovestimation
12:03 PM mrdata- is now known as mrdata
03:16 PM rue_mohr: thats why I was asking, there are a few ways you can do leadscrew torque -> force conversion