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roatating an offset weight calcs needed

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UGMENTALCASE

Aerospace
Joined
Oct 10, 2011
Messages
123
Location
GB
Good evening,

I'm working on a tool which requires a weight that is offset from a pivot point to be rotated. I think I've read that many different equations I'm starting to lose my mind and don't think I'm looking at the right thing. I've attached a little PP that decribes what I'm hoping to do.

The tool, is a lifting frame with a gearbox attached, the gearbox is a right angled bevel type, so I want to drive the input shaft, and therefore rotate the output shafts to turn a tool through 90 deg.

I can't seem to find a definate answer to calculate torque needed to rotate the tool. I'm trying to determine what gearbox range I need to look at in order to do the job.

Any help would be great!
 
 http://files.engineering.com/getfile.aspx?folder=7a367e9a-ab49-4bfa-9786-36b2edaee621&file=Torque_needed_to_turn_a_weight.pptx
homework?
max torque= "known radius" x "known weight"
 
See that's what I worked out earlier, but then I think I confused myself by adding in the length of the spanner, and thought that that equation was to calculate something else! As I say well confused myself!
Also the way I read things on another website it made out like the weight was all about centre line of the pivot point not offset, and that the radius was purely just the size of a barrel or something.
 
dividing by length of the spanner will give you the force required to be applied to the spanner to turn it.

where I'm guessing you're getting confused, is as mentioned earlier:
max torque= "known radius" x "known weight"

but, the closer the CofG is to the pivot point (think X axis only), the lower the required torque to turn it.
 
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