Telescoping Pine Tree Fidget

Summary:

This 8.5x7.5x0.75 cm desk fidget is in the shape of a pine tree, and can be shaken to move the interior pieces up and down, expanding to 1.5 cm tall. I worked on this project with @Jemus_2527457, his page can be found here.

Lesson Plan + Activity:

You will create a telescoping fidget device by utilizing sketch offsets and drafted extrusions/cuts. You and your partner will be “accountabillbuddies”. This means you will provide feedback on initial designs and plans, as well as help each other solve problems and troubleshoot errors as they happen. You are NOT REQUIRED to have identical designs, but it will certainly make the process easier.

Assembly:

This model is printed as a single piece, so no assembly is required.

Design:

We located a silhouette of a tree we wanted to use as the basis for our model, and uploaded it to SOLIDWORKS.

Next, we adjusted the size of the image until it fit within a 9x7 centimeter constraint box, then traced the image using the Line tool until we had the outline of the tree. 
 

To begin the creation of the telescoping effect, we used the offset entities tool on the entire outline, creating offsets each 0.1 cm apart. Because each part of the tree was a different size, a different number of offsets was used by each: the bottom section required 16 offsets, the middle 14, and the top part of the tree only needed 11 offsets.

To begin turning the 2D model into 3D, we used the Extrude Boss/Base Feature to extrude the outer edge of our tree by 1.0 cm at a 25° angle. Then, we selected the offset second-closest to the edge and used the Extrude (Cut) Feature, reversing the direction and setting it to cut “Through-All”, and cutting at a 25° angle. We then alternated between extruding and cutting for each of the remaining offsets, but selected “Up to Surface” for the extrusions and selected the original extrusion in order to more easily adjust measurements if needed. 
 

Finally, the Mirror feature was used to reflect the entire model across the front plane. The “Bodies” section of the Mirror feature was selected, and the “Merge Solids” box was checked.

 

Design Choices + Alterations:
 

Upon printing our original design, we were advised to increase the number of offsets and decrease the angle at which the extrusions were made from 25° to 15°, in order to ensure that the pieces of the fidget had enough room to work as intended. Additionally, the printed fidget was only 8x6.75x0.75 cm, much smaller than the 64 square centimeters given by the constraint box.

We used the offset tool to expand our 2D sketch outwards, with each piece of the tree containing 24, 22, and 19 offsets respectively. 

However, after extruding and cutting the 3D model as before, we determined that by adjusting the angles of the Extrusions to 15° and increasing the size of the initial outline, our original number of offsets worked best. 

Shown below are the original printed model, my partner's final product, and my final product.