How to Mirror, Join & Loft correctly

[Anonymous]

Hello, i'm a beginner in Inventor, need your advice.

I simply draw the spline curve, which will be mirrored (pict.1),

Then I need to create more curves in same way on other workplanes, and loft.

But when I loft, I have no normal result (pict.2). Loft selects only half of the side, how to join two curves?

[JDMather · Accepted solution]

It is generally poor practice to mirror spline curves (did you examine the curvature comb?).

A better technique is to mirror points and the create your spline across the plane of symmetry.

http://home.pct.edu/~jmather/content/DSG322/Inventor%20Tutorials/Inventor%2011%20Tutorial%206.pdf

[Anonymous]

No, I didn't.
OK, I'll continue to experiment.

[JDMather]

If you attach the ipt file from your original post - I can show you how I would have inspected the geometry.

[Anonymous]

File

[JDMather]

You are missing constraints and dimensions - your sketches should show as fully constrained in lower right corner of screen while in sketching environment.

In particular - for some reason your sketch is not constrained to the origin - this should be automatic.

Turning on Curvature Display

Adjusting Curvature Comb display - notice the cross-over of the comb at mirror.

You could have added a Tangent constraint, but I recommend that you create fully dimensioned sketch points (or construction lines) on one side and then mirror to the other side.  Then create your spline across the points.

If at any time your sketch does not turn dark (fully constrained) and you cannot figure out why - I recommend you attach the file here and ask questions.

This is what I might expect to see for a spline sketch - notice the geometry has turned dark indicating fully constrained.

[Anonymous]

Where can I find the car body.ipt that you meantion in your tutourial so I can follow along?