Autodesk Inventor

[#1]

All,

I've created a simple loft using a sketched circle and a fixed workpoint. The loft feature is a loft to a point, with a tangent condition set at the workpoint.

I'm looking for a nice smooth 'button' like feature. However, as you'll see in the screenshot there is an annoying 'seam' or 'join line' running from a point on the circular base to the workpoint.

The 'seam' does not display when the loft feature is set to "loft to point" condition.

Can anyone suggest why this is displayed and am I able to get rid of it?

Thankyou in advance,

MarkC

I'm using Inventor Professional 2012 64 bit

[#2]

Here is the part file

[#3]

Hi Mark,

Thanks for posting this issue! Unfortunately, this edge (which we officially refer to as a 'prop edge') is inherent in the way we define periodic Loft faces (i.e. Loft faces that 'loop back' on themselves), and therefore I don't think there's a neat trick to zap this edge from your current model.

However, for more standard surface shapes (such as spheres and torii), we can usually avoid making prop edges. And since the cross-sectional shape of your model is not far from being an arc, would it be satisfactory to simply Revolve an arc-shaped profile? This will give you a spherical surface, and therefore we can create the shape without introducing a prop edge (see attached IPT).

Let me know if you have any further questions regarding this.

Many thanks!

Jake

[#4]

Jake, thanks for taking the time to reply.

Revolve works for me; I was purely experimenting with the Loft to point (with tangency) function to see what it could do.

Thanks for the explanation regards the 'prop edge'.

MarkC