Autodesk Inventor

[#1]

I have a few months experience with inventor now, and I know how to use all the basic and some of the advanced tools in inventor, but I have no clue how I am going to draw this. can anybody assist me with this?

I want to draw a 3D relief of a music clef. I attached the 2D sketch (I used an image to lay splines along the contour). I now want to extrude this shape, but I want a varying height with the thickness of the contour. so, the thin pieces get a low height, the thicker pieces a higher heigt. this image illustrates what I'm looking for: http://www.homebello.com/photos/product/standard/8821380S40272/gold-musical-charms-pendants/14k-gold...

now, how can I do this? I tried a few things with a loft but I couldn't get that to work, anybody has a better idea? thanks in advance!

[#2]

I would replace the splines with tangent arcs and lines to simplify and then create cross-sections to loft.

You might be able to do some interesting things with Boundary Patch rather than Loft.

Update:

I tried the Patch idea, but until you simplify those splines into arcs and lines it looks like it is not going to work very well.

At least put some Smooth constraints between the splines (I would do over as suggested).

[#3]

You could do it with a combination of sweeps & lofts.

Quick example...

[#4]

This is a good video related to your design problem

http://au.autodesk.com/?nd=class&session_id=10379

[#5]

Wow, thanks for the quick responses! I redid the outline sketch, this time with lines and arcs. I also made few crossections for the lofts and extrusions. I decided to make the part with two lofts and two extrusions, as can probably be easily seen in the attached file. the extrusions are of course no problem, but I'm still struggling with the lofts. I decided on using railed lofts, and I tried a few different settings (including manually inputting the transition points), but I keep getting the 'no meaningful result' error. doe anybody know what I am doing wrong? Thanks again!

[#6]

When I suggested arcs - I meant really simplify with very few arcs.

I'm guessing that I could get essentially the same geometry with half as many arcs.

Find a location that is nearly one radius value on three tangent arcs.

Use three points to define a new arc across all three.

Measure the difference at greatest difference.  Is it really that great that it is of any real (manufacturing) significance?

I think this can be greatly simplified still further.

For example - this single arc replaces 6 arcs and it looks like it might even go down further without significant difference.

The difference thus far amount to the thickness of two sheets of paper.

The trick to to find arcs on the curve that very little.  And of course - in the end the curves must be tangent.

[#7]

you're probably right, but decreasing the amount of arcs still gives a loft rail that consists of multiple arcs. using less arcs would have saved me time, but it wouldn't make any difference for the trouble I'm having making the loft, right?

[#8]

I didn't even bother to look at the Loft problem yet.

I always tackle one problem at a time.

If it were my part I would get the rails simple and tangent first, then worry about the profiles.

In some cases I might work back and forth between profiles/rails, but always simplify, simplify, simplify.  More with less.

Steve Wozniak ("The Woz" - Inventor of first Apple computer) wrote a good book on this philosphy.

In the example Mike posted earlier he used mostly Sweep.

Not sure if I would use mostly Sweep or Loft, but I would be willing to try several ways.

Note that in Loft 5 it might be better to set the beginning and ending conditions Tangent.
You can't do this from sketch profiles - only from surfaces or solids.

[#9]

I found the solution! the key was adding more cross sections. when I loft now, using the sketch as rails, it works perfectly. Thanks!