Gear up for the holidays with a STEM inspired tree!

Step 1: Make Your First Gear

Make a gear using the gear maker included here. I set the module to 4 and the teeth to 20 (and the width to 10mm) , but you can experiment with different configurations.

Step 2: Extrude Cut a Hole

Sketch a hole in the center of the gear and extrude cut it. This is where we will eventually feed the string that appears in our final step. Save it as gear1.

Step 3: Make Your Second Gear

Go back to gear1 and reopen the gear-maker. Decrease the number of teeth by 2. Save it as gear2.

Step 4: Make Your Third Gear

Go back to gear2 and reopen the gear-maker. Decrease the number of teeth by 2. Save it as gear3.

Step 5: And Repeat!

You can see where this is going. Continue repeating that workflow until you have the number of gears (“fronds!”) you’d like for your “tree.” I made 8 unique gears, plus a “star” (I made the star with the gear maker. I used module 2 and added 5 teeth) and a trunk.

Step 6: Make the Trunk

Extrude a circle until you have a cylinder. Extrude cut two equal rectangles out of this cylinder.

Step 7: Assemble the "Tree!"

Go to gear1 and select “Make assembly from part.” Make sure you place gear1 at the origin. Add gear2 by “Insert Components.” Move gear2 by selecting Move Component and then selecting To XYZ position. If you’d like to print this as one whole object, move the gears so that they are directly on top of one another. (So gear1 on XYZ would be 0,0,0; gear2 0,0,10; gear3 0,0,20 etc.). If you’d like to print the gears so that they spin (or so that the “fronds” are different colors) you’re going to want to place the gears slightly above the gear below (I set mine 2mm apart, meaning gear1 on XYZ is 0,0,0, gear2 0,0,12; gear3 0,0,24 etc.) or simply print them as their own individual parts.

Step 8: It's Print Time!

If you opted for the non-moving tree, it’s time to pick a color and start up your machine. For the moving gears – If you’d like to alternate colors like we did here, I suggest you print in pairs to save time -- gear1 and gear7 together, gear2 and gear8 together, gear3 and gear5 together, gear4 and gear6 together. Both SolidSorks assemblies are attached if you'd rather skip the previous steps!

Step 9: Time to Assemble!

Feed the star onto a string, followed by the gears in reverse order (8,7,6…) all the way to the trunk. Now use the string to loop back through the other rectangle of the trunk and back up through the gears, this time in chronological order (1,2,3 etc.). Gear yourself up for an awesome looking tree because your new ornament is ready!! (The STLs are all attached for your convenience!!)