How to make a rope

[tmox]

Really a cable. tiny aircraft cable.
I want to wrap the cable from a fixed end (on a moveable assy) thru a series of pulleys and intermediate surfaces to the business end where a linear force will be applied to operate the gizmo.
So a flexible cable of fixed length that can move the tip of the assembly by contracting a series of pulleys from a straight line to a "circle". one pulley is fixed and the rest move toward it. this single cable will have approx 8-10 different tangent constraints.
I'm using 2010 demo. Suggestions for tutorials or demos to get me going?

 

[Jabberwocky]

I don't know that what you're asking for is possible. I haven't worked with any of the cable/routing tools but you sound like you want a kinematic simulation of a flexible body which I'm sure Inventor can't do (or any other CAD I've heard of).

However - assuming you know about the pulley series you can easily fake this using math, chiefly length constraints and parameter ratios for the lengths of your straight line segments. Using the arc-length tool (dimension both end points and the curved segment) you should be able to work out the round portions as well.

 

[tmox]

I know that it's possible to create the expected resulting movement of pulleys and to have the lengths of rope between pulley centers change length to accomdate the new distance, but, that's not really going to show what i want.
I could show it , but, it wont tell me anything. I have a linear(ish) arrangement of pulleys with pivot points between some pulleys, like a finger. when i contract the system (with the rope) does the end pulley arrangement contract first? do they all contract simultaneously? is there a sequential collapse?
this info won't come from faking the view. I know it will probably come in a protype, if it gets that far (not) but, still it would be nice to find out if we can do a rope.

 

[GregLocock]

I would do it with a proper mechanisms analysis package, such as Nastran 4 or working model 3d or ADAMS. It would take several days to get it working, but once it is debugged analysing variations to get the right sequence of events would be fast.

I suspect a keen hand could build a mathematical model more quickly.

Cheers

Greg Locock


New here? Try reading these, they might help FAQ731-376

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[mcgyvr]

I suspect this could be accomplished with the dynamic simulation portion of Inventor.
You won't be able to do it with the rope as you want but you should be able to simulate the movements of the pulleys properly.

 

[rollupswx]

If you have Inventor Professional with Dynamic Simulation see this book

http://www.vdssolutions.co.uk/

as indicated you won't animate a rope, but you can dynamically simulate the motion.