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1 Attachment(s)
Torque
I am trying to calculate the torque required to rotate a mass around a shaft. See attached.
[ATTACH]1065[/ATTACH]
m = 315 lbs.
w = 10"
h = 16"
d = 9"
r = .75"
T = Iar (a is angular accel.) (r is
I = I[SUB]1[/SUB]+md[SUP]2[/SUP]
I = 1/12 mw[SUP]2[/SUP]+ 1/3 mh[SUP]2[/SUP] + md[SUP]2
[/SUP]I = 2625 + 26880 + 25515 = 55020 lb-in[SUP]2[/SUP]
Mass rotates 90 deg in 3 sec.
average speed = pi/2 * 1/3 = pi/6
pi/6 = at
a = pi/18 rad/s[SUP]2[/SUP]
T = 55020 * pi/18*.75
T = 7202 in-lbs
My biggest problem is calculating the angular acceleration (a). I know i did not do it correctly. THe mass rotates from rest (0 degrees) to 90 degrees in 3 seconds.
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PS.. I am trying to size a quarter turn actuator which is why i need the torque. I am trying determine if i can drive 3 of these sections off of (1) actuator.
The mass is a load on a platform and the shaft will be rotating to dump the platform. I have multiple platforms in series. Therefore, my max torque will be the initial torque, since once it starts rotating the mass will continually drop. Once i have passed 45 deg gravity should assist.
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Check the following webpage and Calculator -->
[URL="http://www.engineersedge.com/mechanics_machines/mass_moment_of_inertia_equations_13091.htm"]
Mass Moment of Inertia Equations[/URL]
[URL="http://www.engineersedge.com/calculators/rectangular-plate-mass-moment-inertia.htm"]Mass Moment of Inertia Rectangular Block[/URL]
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The above ideas are very clear and fine regarding the torque. Thios is also beneficial in case off engeneering purposes.