How rig a crane so the crane wires extend as the hook is lowered

[alastairerrett]

Hi Everyone

 

I have a crane I'm trying to rig that I need some help with. I need to rig the crane so that as I lower the hook of the crane the wires attached to the hook extend. I tried doing it with a LinkedXform but although I got the wires to extend as I lower the hook, ass soon as I rotated the boom of the crane the wires went off in a strange direction.

 

Does anyone know how to do this?

 

Thanks

[jasond]

You could use the linked Xform modifier for this... Create a spline in the shape that you way, so it's probably a U in this case. Then link the bottom-most vertices to the hook mount. When you move the hook down, the spline will now stretch down with it.

[alastairerrett]

Thanks for the reply. I wanted to get it so I didn't have to go in and edit the vertices every time it moved. Your animations look great though

[Corey Beaulieu]

Have you tried a LinedXform modifier? If you select a vert, place a point help on it, and then add a linked xform while the vert remains selected, you can animate the helper.

[alastairerrett]

Have you tried a LinedXform modifier? If you select a vert, place a point help on it, and then add a linked xform while the vert remains selected, you can animate the helper.

 

Hi, Yeah I tried a linked xform and I could get it to extend the crane wires but then when I move the boom of the crane the wires break off from the crane. I think it's to do with the pivot point but I can't sort it at the moment and I don't see why adding the linked xform would change where it pivots from when it was working fine before adding the linked xform

[Corey Beaulieu]

I have had that sort of trouble before, but my experience on this type of animation is limited. I don't remember my workaround, but I know it wasn't elegant.

[alastairerrett]

Hi Guys,

 

I've created a very simple crane rig in Max so you can all see the problem I'm having more clearly. As the crane boom is rotated down or the base rotated the linked xform stops working and the wires go off at an odd angle.

 

Any help would be greatly appreciated. Thanks for the help so far

Mechanical Linking-Crane Mockup.zip

[alastairerrett]

Give this a try. You were almost there. The only two objects you now need to animate are the parts coloured red, the pulley and the boom pivot

[ATTACH]52318[/ATTACH]

 

Hi thanks George that looks great. I've now managed to do this using two hose objects 'bound to object pivots' for the crane wires. I'm going to have a go at reproducing yours as well so I have two methods and I'll see which one works best and is easiest to setup.