Rope Pulley motion simulation

[zidanelam]

Hello,

 

Can I know how can i do rope and pulley simulation? I would like to use a rope to lift up a crane. I have tried Belt and Chain, but the belt is in closed loop. I have drawn out the blocks of the pulley, crane and all the mechanism, now i would like to link them with a rope

 

Please guide me how to do this simulation in 2D as well as 3D

 

Thanks in advance

[shift1313]

Having an object moved in that manner isnt too difficult but actually showing the rope change is a bit more complex of a problem. Do you simply need something to raise or do you actually need the rope to look as though its moving? How far are we talking about?

[zidanelam]

I want to make the rope move, in pulley manners. Meaning to say that, if i pulled the string, it will increase the length of rope in my side and decrease the length of rope on the other side of pulley.

 

I can make the object move, by adding relation. But I can't relate it with the string.

[shift1313]

What version of SW are you using?

 

Off the top of my head im thinking you will need to have an equation setup for your rope length. You can make things "flexible" and adaptive in a sense but pulling the rope will be tough. Let me give it some thought and see if i can come up with a good way to do this for you today. If you are using 2009 or newer i will be able to upload a file for you to see. If you are using 08 or older you will not be able to open any file I create.

[zidanelam]

I'm using SW 2010, should be no problem.

 

Thanks for your help

[shift1313]

I have tried something with no luck. Do you really need to "pull" the rope or can it be animated with the rope/box moving around the pulley? The dynamic pull on the rope is the issue. There is a work around( i think) by making two ropes. The end of one rope in the assembly will have the other based off it but i still dont know if this will work.

 

Let me know what your end goal is and I will see what I can do.

[bhamze]

I think this can be accomplished by utilizing in context modeling. Basically, I'm thinking of using a hidden object to drive the rope. I've used this technique in the past to animate a speaker gasket. I will give it a try later, I'm very busy though.

[zidanelam]

Thanks for your efforts, I think it's not very important to do the simulation. What I'm doing now is building a robot with pulley attached to it. Basically, I would like to do simulation first before coming out the real prototype. Anyway, I really appreciate of what you have did, I know it's not an easy task. Don't worry, this is not really important

[zidanelam]

Or you can recommend me any modeling software that can do this simulation easily.

[shift1313]

Well you can easily do a motion simulation that doesnt involve the rope, rather a force on the pulley. Can you maybe post a screen shot of what you are working with and some notes on the sort of motion you want.

[bhamze]

Here's a quick animation I created in SW2010. If you want the SW files, let me know. Is this similar to what you want to accomplish?

 

http://www.youtube.com/watch?v=rotKs_bgoZA

[shift1313]

That looks great bill!

[bhamze]

Thanks Matt

[zidanelam]

bhamaze, Yes!! this is what i need. Can you send me the SW file?

 

Thank you very much

[bhamze]

Here you go. Pay close attention to the equations in both the part and assembly files. Also take note of the relations between the different parts. This may look basic but as Matt said....... it very complex. If you're having trouble, let me know. I'll try my best to help.

 

You need to download both files, this post will contain the assembly followed by the part files.

Pulley.zip

[bhamze]

Second set of files

Pulley2.zip

[dick_timmerman]

Maybe this link can be of help:

 

http://www.youtube.com/watch?v=j3Y7CeeN83U&feature=related

[ntweisen]

I have an assembly which is essentially a pulley and a counterweight. Everytime I move the counter weight up or down the connecting cables do not stay attached. I have to rebuild/update in order for them reconnect to their proper positions. Is there any way I can keep all the parts attached and connected together without having to update/refresh/rebuild the part?

[bhamze]

Do you have a mate that drives the counter weight? If you change the mate value the assembly should automatically rebuild. If your dragging the weight I think the only option is to manually rebuild assembly.