Loft cannot create uniform surface

[Anonymous]

Hello everyone,

I am quite new to inventor so please excuse my question. I want to make a part that has a rounded surface on top and a flat surface on bottom. I don't want to use round fillet because it only makes round edges and not round surface. So I went for the loft feature. I created a point, the distance of which is equal to the thickness I want the object to have. I selected the tangent to point condition and clicked ok. The result is almost what I want, except for the surface is not equal rounded. As you can see in the picture there are some tine edges created!! I also attach the part file for your reference. How can I create an equal rounded surface?

[mpatchus]

Welcome to the Forum.

Keep in mind that there is ALWAYS more than one way to model a part.

If you aren't getting the desired results one way, try modeling the part using a different approach.

One thing that I always told my students was to think about how the part will be made.

Is it machined from a piece of stock?  If so, there is nothing wrong with starting with a piece of stock and removing material the same way a machinist would.

Example file attached (using my own dimensions since I cannot open your 2017 part).

[JDMather]

Can you explain a bit about your Design Intent - what is this part, what is it's function?

Attached is another possible "solution".

[Anonymous]

Hello guys,

thank you for your rapid reply and help! This piece will a part of a necklace that I want to create. The manufacturing method for the prototype will be 3D printing. However the triangle shape is just an example. The solution of Mike is nice but I am afraid that with more complex shapes (such as a shape which contains big and small curves) than a simple triangle some fillets may not be able to be applied!

The solution of JDMather is also good, so I will try it as well.

Thank you both for the time you spent!

[johnsonshiue]

Hi Chris,

This is a very interesting case. Actually, it is somewhat open-ended, meaning there are multiple ways to do it and there are multiple solutions. Attached is one using Boundary Patch. Loft works the best when the topological transition is not too drastic from one section to another. In this case, the Loft goes from a section with 6 segments to a section with 1 point. It is a bit extreme.

Boundary Patch fits a G2 continuous surface with a given boundary loop. You can tweak the boundary conditions and apply guide geometry. Another workflow to consider is Freeform. It is very good at creating organic shape.

Many thanks!

[Anonymous]

Hi Johnson,

Thank you for your reply. Yes, I think I will try the boundary patch to see how it works.