Forces and Torques Required on a "Fishing Reel" style Winch

[P Brown]

I have attached a simple drawing of a winch that I would like to design. To get the size of the spool, hydraulic motor and winding arm correct, I need to figure out the formulas to calculate the torque needed to rotate the winding arm and the forces on the rope at each section. (ie. W,X,Y and Z where Y and Z are the spool empty and the spool full (z). The reaction load at W is 250 lbs. Think of this as a large fishing reel that you can cast line out and reel it in. This is the style of winch I want to design, but I need to know the formulas to calculate the forces on the rope to then optimize the design and size the hydraulic components. Can anyone help me with the pulley formulas to calculate the forces, assuming all the angle changes are friction free?

 

[dvd]

Before you learn how to move stuff with this winch - how are you going to lock the load in place? Otherwise, get a book on statics and start studying that, then ask more specific questions.

 

[P Brown]

Okay. I will try to clarify. In this example, I should have stated that the system will be static to calculate forces on each section. The end "W" will be dead headed, along with "Y" and "Z". There will be a pull force of 250 lbs. on "W". What torque on the winding arm will give a force of 250 lbs "W". and then the tension force on "X","Y", and "Z"?

 

[3DDave]

This is a Statics week 1 level problem and is probably also handled in the vector part of Physics 1. From here, all design questions to be answered about this device get much harder, so it's unclear what answering this part will do to help.

 

[BEMPE16524]

if you think my spreadsheet is helpful, please use it. Otherwise just ignore it.


R.Efendy