hey,

I've been working on this model a couple of days now and it's starting to freak me out.

It's going to be handgrip for a bycicle or scooter.

I've tried to model the rope shape before and succeeded using two sweeps. I attached this model as well. The problem with this first try-out was that it wouldn't be very nice to grip your hands around, that's why it wanted to use more elliptical shapes than round ones, to make the whole model a bit smoother. Here you can see that old model.

The key to making realistic rope is to first make the simple rotated sweep consisthing of three (or more) intersecting circles. After that, you create little circles on the edge of the surface of the basic shape. You sweep the little circles on a helix following the sweep of one of the bigger circles and you're almost done. If you look closely to the little fibres of the rope you'll notice they twist a bit in the opposite direction of the big sweep, so you have to twist the second sweep as well but in opposite direction.

Now for the smoother model it gets problematic:

- the basic shape is possible, you can make it in the same way as the first model, only draw 3 intersecting ellipses instead of circles.

- the fibres are the problem, and I'm stuck at rotating the fibres in the opposite direction of the big sweep. When you rotate the fibres in the opposite direction they go off the surface of the model, because they are projected at the edge of an ellipse: An ellipse behaves differently from a circle when twisted.

What happens in the old model is that the little fibre-circles on the surface twist around the circles profile, you can also say they rotate/move along the edge of the bigger circles.

So the same should happen on the new model, only then the little fibre-ellipses should rotate/move allong the edge of the big ellipse.

I don't know if this is possible in solidworks. I think it maybe needs some programming or math. I tried using the equation function in solidworks, making the orientation of the ellipses dependent of the length of the model, but I didn't succeed.

I someone in the mood for a challange and wants to help me?

If you have any questions about the model or want some more explanation because my text above wasn't very clear, please let me know.

thanks,

Jip