Animating a cable

Hi all,

I'm struggling a little bit with this, so I thought I would throw it
out to see if anyone has any brilliant ideas.

I'm working on an animation of a tool that I built to measures he ID
and OD of steel pipe. The tool get's inserted in the pipe and the
operator turns a crank on which are mounted laser sensors for
measuring distance. A data acquisition system collects the data for
post processing later.

There is a cable mounted to the end of the crank handle which is
connected to a bag on the operator's shoulder. I've modeled the cable
with a spline and swept it, but as the crank rotates through it's
throw, the geometry of the spline can get quite unpredictable.
Ideally I would like the length of the cable (spline) to remain
constant with the loop in the cable changing as the crank turns.

Any bright ideas on how to reliably do this?

Thanks,

===========================================================================
Chris

 

It's amazing that most of the time once you verbalize the problem, the
solution comes to you.

I created a sketch on the bag with a construction line perpendicular
to the surface of the bag at a dimensioned distance, I then provided a
construction line perpendicular to that. Then I created a sketch at
the handle with a construction line concentric to the handle. I
created a plane from the first perpendicular line and the end of the
second point. Using this plane, I created a construction sketch which
would be the loop of the cable with suitable dimensions (I provided a
length of the vertical line coming from the handle. I then created a
3D sketch using the previous three sketches as lock down points.

It works fine as the handle goes around.

l8r
===========================================================================
Chris

 

Chris


This sounds great but I dont quite follow. Do you have a model I can
dissect?

Ben

 

I'll have to create one. The ass'y I'm currently working in has LOTS
of parts ;>

Is your e-mail valid?


===========================================================================
Chris

 

Chris

For the email just remove ".spamballs" without the quotes and it is
valid. Thanks for your time!

Ben


Ben

 

I'm slowly trudging my way through this one and have another one that
has me flummoxed.

Part of the process of measuring this pipe is to use a paint pen to
draw reference lines on the pipe. In this particular instance there
are 16 lines drawn at equidistant angles.

I've managed to animate this by building a small cut feature on the
pipe and then using an equation to make the length = to the distance
of the pen from the end. However, how do I do the other 15? Doing it
this way means all the existing marks will reset as the pen sweeps
through it's stroke. You can't animate the cut length of a feature,
I've tried that. What I want to show is the pen making 16 marks
around the periphery.

Any brilliant ideas?

Thanks,
===========================================================================
Chris

 

I'm slowly trudging my way through this one and have another one that
has me flummoxed.

Part of the process of measuring this pipe is to use a paint pen to
draw reference lines on the pipe. In this particular instance there
are 16 lines drawn at equidistant angles.

I've managed to animate this by building a small cut feature on the
pipe and then using an equation to make the length = to the distance
of the pen from the end. However, how do I do the other 15? Doing it
this way means all the existing marks will reset as the pen sweeps
through it's stroke. You can't animate the cut length of a feature,
I've tried that. What I want to show is the pen making 16 marks
around the periphery.

Any brilliant ideas?

Thanks,
===========================================================================
Chris

 

Sorry,

This was supposed to be attached to thread about animating a cable.

===========================================================================
Chris

 

Well,

In the immortal words of "brute force", I made a part which I inserted
16 times into the assembly. I keyed the individual stripe on the
pipe to the location of this inserted part(s) via an equation. The
parts are completely embedded in the pipe, so they are not visible,
but I can control the mates of each parts correspondingly controlling
the stripe.

Wow, this is ugly. But I now have control over the strip which allows
me to "animate" it.

The neat part of all this is the animator doesn't play particularly
nicely with sub-assemblies (or patterns BTW) so I've had to explode
all the sub-assemblies that I needed to animate parts in. I've got a
bazillion parts and corresponding mates to trudge through. This is
going to be tedious.

===========================================================================
Chris

 

Argh!

Animator in Swx 2005 doesn't like all the equations. Switching to the
animator pane produces a CTD.

Any suggestions for clever ways to independently animate multiple
stripes?

cd