Inventor General Discussion

## Inventor General Discussion

Member
Posts: 3
Registered: ‎11-20-2013
Message 1 of 7 (477 Views)

# How to make surface from equation?

477 Views, 6 Replies
11-26-2013 01:51 PM

Hello

I need to make a model of saddle surface. The surface is given by equation z = y^2 - x^2, and I must have some thickness - It will be printed on 3D printer.

I have Inventor 2014 and I dont see possibility of making the surface directly in Inventor. Is there any trick for that?

I'm afraid I cannot use solution as stated here Equation-driven surface , because saddle surface looks like this hyperbolic paraboloid .

I tried this solution: I made 3D surface in Matlab, exported it in .stl and opened in Inventor - but this only makes the surface with no thickness. Functions extrude, loft require 2D sketch. Any trick for this?

Thank you

Mentor
Posts: 188
Registered: ‎08-15-2006
Message 2 of 7 (457 Views)

# Re: How to make surface from equation?

11-26-2013 02:50 PM in reply to: dalecanka

dalecanka wrote:

I'm afraid I cannot use solution as stated here Equation-driven surface ...

Unless my math fails me, you can do exactly as explained in that link. Can't you get it by sweeping z = x^2 along z = -y^2?

Depending on how you want this printed, one of the attached (or a variant) should be a good starting point. Let me know how it works, and post a picture of your printed part!

Distinguished Mentor
Posts: 703
Registered: ‎02-04-2010
Message 3 of 7 (412 Views)

# Re: How to make surface from equation?

11-26-2013 07:17 PM in reply to: dalecanka

Hi!

If you got the stl, Convert the stl to iges. (Autocad Mechanical will translate stl to dxf or igs)

Then in Inventor, open the iges and apply the Thickness Tool to the surface. (in Inventor, You can't use Thickeness tool directely in impoerted stl)

Did you find this reply helpful ? If so, use the    Accept as Solution or Kudos - Thank you!

Regards.
CarlosC

Autodesk Inventor 2014 Certified Professional
Autodesk Factory Design Suite Ultimate 2015
Windows 7 64Bit
Employee
Posts: 115
Registered: ‎06-10-2004
Message 4 of 7 (396 Views)

# Re: How to make surface from equation?

11-26-2013 11:03 PM in reply to: alewer

alewer nailed it.  If the parameter d4 is changed to 2 inches, the parallel sweep surface will become exactly like WolframAlpha's example.

Glenn

Autodesk T-Splines Component Development
Employee
Posts: 115
Registered: ‎06-10-2004
Message 5 of 7 (355 Views)

# Re: How to make surface from equation?

11-27-2013 12:04 PM in reply to: GlennChun

Just FYI, alewer's model creates a surface of z = x^2 - y^2.

If you want z = y^2 - z^2, change the sign in each equation in alewer's model, and you will see this surface:

Glenn

Related topic:

Hyperboloid of One Sheet

Autodesk T-Splines Component Development
Member
Posts: 3
Registered: ‎11-20-2013
Message 6 of 7 (303 Views)

# Re: How to make surface from equation?

11-28-2013 01:38 PM in reply to: alewer

I think I misunderstood the sweep tool before. Your solution works - I took your model of saddle, adjusted it a bit and added a holder (see in attachment).

As soon as I have photo from 3D printer, I will post it here.

Member
Posts: 3
Registered: ‎11-20-2013
Message 7 of 7 (219 Views)

# Re: How to make surface from equation?

12-19-2013 04:32 AM in reply to: dalecanka

See the printed model in the attachment. Thank you for your advances

### You are not logged in.

Announcements
Are you familiar with the Autodesk Expert Elites? The Expert Elite program is made up of customers that help other customers by sharing knowledge and exemplifying an engaging style of collaboration. To learn more, please visit our Expert Elite website.

### Maintenance Subscription Resources

Upgrading to a 2015 product? Make sure to check these out 1st!

### Inventor Exchange Apps

Created by the community for the community, Autodesk Exchange Apps for Autodesk Inventor helps you achieve greater speed, accuracy, and automation from concept to manufacturing.