## Introduction: ORU Christmas Tree Ornament

Here is a tutorial showing how to create one of Tulsa's iconic buildings located on the Oral Roberts University Campus, the Prayer Tower. I have assumed that those following my tutorial have at least a basic knowledge of the use of solidworks or other similar CAD software.

## Step 1: Step 1: Creating the Base for the Tower

Start of by extruding a 0.6 in diameter circle .05 in upwards from the centroid on the top plane. Draw a 12-sided polygon centered on top of this disk, sizing it so that a 0.25 in circle fits inside. Constrain one side to be vertical, this will orient the polygon properly. Extrude this to be 1.2 inches tall.

## Step 2: Step 2: Creating the Observation Deck

To build the observation deck, start off by creating a plane set 1.3 inches off of the top plane. Draw a centered circle 0.75 inch diameter in this plane and create a lofted feature selecting the circle you just made and the face of the twelve-sided cylinder. Create a second plane 1.31 inches from the top plane, drawing a 0.74 inch circle on it. Loft between the top of the first loft and this new circle. This will be the base of the observation desk. Extrude 0.1 inch up from the new loft using its edge to define the extrusion. To finish off the deck, create a 3rd plane 1.42 inches above the top plane and draw a 0.75 inch diameter circle in this plane. Loft between this circle and the top of the cylinder you just extruded.

## Step 3: Step 3: Finishing the Basics

To top of the observation deck, we are going to build the spire. Start off by creating a plane 1.5 inches from the top plane. Create a 0.25 inch hexagon, setting one side as vertical as with the polygon to orient it. Create a loft between the hexagon and the top of the observation deck. Next create another plane set 2.5 inches away from the top plane and make a 0.1 inch hexagon. Loft between the two hexagons.

## Step 4: Step 4: Adding Some Flair 1

In this step, we will make the spikes that surround the observation deck. The first part of this is a little tricky. First, in the front plane, draw a line down from the very outer ring of the lower edge. Set it to be vertical, this will allow you to gauge your angle. Next create a line coming down from the same point, set it to be 15 deg. clockwise from your first line. The next line you will need to make will be a 3d sketched line in the yz plane perpendicular and connected to the angled line. After this create a plane coincident to the two end points of the angled line and the end point of the 3D sketched line. Sketch a 0.03x0.015 box centered on the same point where the lines in the front plane touch the rim of the observation deck and extrude out 0.25 inches. Create a circular pattern with 24 of these using a circular edge. To finish off these spikes, create a plane on the top tip of the spikes. Do this by creating a plane parallel to the top plane and coincident to the top tip of the spike. Next create a box 0.11 inches long constrained to be the same width as the spike, "balancing" on its tip with 0.05 inches hanging past the tip away from the model. Extrude this 0.015 inches upwards, and 0.003 inches downwards. The downwards extrude will give this more strength. Create a circular pattern with this extrude as you did with the spikes.

## Step 5: Step 5: Adding More Flair #2

In this step, we will add the connecting piece between the little spikes on the big spikes. In order for this step to turn out, everything needs to be done very carefully. First off, draw 8 lines as shown in the second figure above. Be careful that no unwanted constraints are automatically added. you will want the two lines that lay along the little spikes to be coincident with the former at both ends. Number each line 1-6 starting with the top left going clockwise.

Lines 1 and 7 are equal length, as are 3 and 5 as well as 4 and 8.

Lines 1 and 5 are colinear, as are 3 and 7

Lines 4 and 8 are parallel and 0.025 inches apart

Lines 2 and 8 are equal, set line 2 to be 0.08 inch long

Position lines 2 and 8 in the center of the small spike by first drawing a point on the small spike's midpoint, then constraining it to be the lines' midpoint as well.

Extrude this downwards 0.018 in

That will produce the connecting webbing

## Step 6: Step 6: Windows and Doors

The Prayer Tower has windows all the way down its bottom column, here is how we will make them. Pick any of the faces on the 12-sided column and draw a 0.01x0.05 in box. Set the box to be 0.01 in off of the base and center it using the point trick used in the last step. Extrude up 0.075 inches and draft it 3 deg. inwards. Create a linear pattern up the column with 24 copies set spaced 0.05 inches apart. Next do a circular pattern of the linear pattern, with 12 copies-one for each side.

## Step 7: Step 7: Using Patterns

In this next step, we will put the design on the spire of the tower. Start by creating a triangle along on one of the 6 sides of the spire that has either the front or right plane adjacent. Make it with the long side going 0.65 inches up, and the bottom being 0.06 inches long. Inside of this triangle draw 8 horizontal lines spaced 0.05, 0.04, 0.05, 0.04, 0.05, 0.04, 0.05, 0.04. Using the = (the first 0.05 or 0.04 line) in the smart dimension for the alternating lines will help out. Next use the snip tool to snip the vertical sides where the horizontal lines are 0.04 inch apart. Extrude 0.075 inches up and draft 5 deg in. Mirror this over the adjacent plane, and do a circular pattern around the spire. To top this all of, extrude a 0.05 diameter circle centered at the top of the spire up 0.08 inches. Set a point on the centroid of the cylinder(0.04 inches up). Draw a 0.02 inch circle and use the extruded cut tool to cut "through all" both directions. This will be the hole for the wire to hang the ornament.

## Step 8: Step 8: More Flair

Next create a plane 1.2 inches from the top plane. This next step will be much easier if you do a section view cutting along the plane you just created retaining the bottom part of the tower. Next create the tetrahedral shown in the figure above, setting the two pairs of lines equal together. Set the distance between the corner of the tower and the tip of the shape to be 0.02 inches and the distance between the pointed ends to 0.03 inches. Go 0.3 inches down and place a single point on the corner of the 12-gon. Form a loft from the tetrahedral down to this point. Do a circular pattern around the column, doing 12 iterations to put on on each corner.

## Step 9: Step 9: More Windows

To create windows on the observation deck, make a plane set 0.37 inches away from the front plane. In this plane create a 0.02 inch wide rectangle the height of the center of the observation deck. extrude this 0.05 inches and draft it 5 deg. Create a circular pattern of this, setting it to make 24 of them.

## Step 10: Print It!

To create a printable file, go to File>Save as, choose type to be .stl and save the file. This format will allow you to input the CAD file into the 3-D printers software and print this model off!

Or if you like, you can use the file that I have attached (:

Very nicely done! I love that you included the steps you took to create this ornament design. Good luck in the challenge!

Thank you!