SOLIDWORKS: Design Review of ImpossiBell Ornament – Part 1

SOLIDWORKS: Design Review of ImpossiBell Ornament – Part 1

Table of Contents


As the holiday season approached, Hawk Ridge decided to host a design challenge for a 3D printed tree ornament. Everyone who submitted a design would receive their ornament after being printed on one of our HP 3D printers. All submissions were required to fit into a 2” cube bounding box and the eyelet geometry was provided to us.

I wanted to create something that could only be manufactured by 3D printing.  With this in mind, I knew I wanted complex undercuts or drafts that couldn’t be achieved by traditional molding. I also wanted it to incorporate an as-printed assembly. You can see the end result below!

Finished ImpossiBell

This blog and the companion YouTube video details some of the key design steps and thought process I took during the design. A second blog and video covers the design checks, rendering output, and the finished 3D print.

I liked the idea of an actuating bell and decided to start off with an overall shape that was a twisted loft. When generating the shape of the body I initially used the solid Loft feature through three polygons with a single feature and some twist, but I was unhappy with the result. Splitting up the loft into two features allowed me to create the more angular shape I desired, as you can see below.

Splitting up the loft into two features

Midway through the design, I decided I was unhappy with my boring straight concept for the mounting arm. Rather than deleting my features to that point and creating more re-work, I employed direct editing commands like SplitMove/Copy Body, and Move Face to essentially bend the arm into the shape I wanted.

Employed direct editing commands

After adding more detail to the design I wanted another flair to showcase the 3D printed nature and wanted to add perforation to the exterior. Simple cylinders were extruded and then patterned along Face Curves with a curve driven pattern. I adjusted the size and position of the cylinders to my liking with the move/copy body command and move face command before subtracting them from the bell body to produce the final hole pattern. This gave me the control I wanted to get the look just right!

ImpossiBell with pattern along face curves

As far as manufacturability is concerned, this design features a wall thickness of 1 mm, with a minimum hole size of about 1 mm as well. In practice, we have found that with our HP 3D printers we are able to print details and wall thicknesses even smaller! I modeled in 0.5mm of nominal clearance between the components to ensure ease of post-processing.

To see the finished 3D printed result, along with validation steps for the assembly and rendering output, check out Part 2 of this blog!

For more information, check out our YouTube channel, get a SOLIDWORKS 3D CAD quote or contact us at Hawk Ridge Systems today.

Picture of Ryan Navarro

Ryan Navarro

Ryan Navarro is a mechanical engineer and an avid SOLIDWORKS user since 2007. As product manager for CFD analysis, he specializes in complex simulations related to fluid flow, as well as structural interactions and mold filling.