Intro: Perfect Wooden Sphere
Wooden spheres can be helpful for an entire range of crafts, decorations, and even art. This project was mainly for practice for an upcoming instructable, but also a proof of concept for the process.
A sphere is a three dimensional object where every point on the surface is the same distance from the center. With this elementary knowledge, the process shown below for turning a sphere on a lathe makes a lot of sense. As the sphere is turned on the lathe through all three axis, all the points on the surface become the same distance from the center.
This project is simple enough to complete in a few hours. I recommend trying it out if you want to learn a new technique for your wood turning.
Step 1: Tools and Materials
Step 2: Glue Hardwood Mounts
Cut scrap wood into a blanks that measure 4 x 4 x 3 in. and 3 x 3 x 3 in. when glued together. Glue and clamp until dry.
Step 3: Turn Drive Cup
Mount the blank to a face plate using turners tape and tailstock. Once round, drill a 7/8 in. hole. Tap the hole using a wood tap that matches the threads on the spindle. Cut a relief in the threads and mount on the spindle. Turn the cup round once more and cut a 1/2 in. deep cove. Sand smooth.
Step 4: Turn Tailstock Cup
Mount the tailstock cup between a faceplate and tailstock. Turn round and cut a cove matching the drive cup. Reverse the drive cup and mount in a a nova chuck. Cut a clearance hole in the back of the cup the size of the live center for the tailstock.
Step 5: Apply Plasti Dip
Using painters tape, mask off the cups. Apply between five and eight light coats of plasti dip spray. This will give traction to the cups.
Step 6: Turn Firewood Round
Mount a piece of wood between centers. I used an old piece of firewood. Turn until round. Using calipers, measure the diameter of the wood. Transfer that diameter lengthwise on the wood.
Step 7: Turn Rough Sphere
Using the marks from the previous step, turn a rough sphere. Cut the sphere from the lathe.
Step 8: Mount Rough Sphere
Mount the sphere in the cups and turn the high points down.
Step 9: Turn Sphere Round
To perfect the sphere, find some recognizable marking on the sphere that will help you orient it between the cups. There are three main axes to turn the sphere through. Orient the sphere on the first axis and remove only the high points. Do not cut into the sphere past any low point. Loosen the tailstock and reorient the sphere to the next axis. Repeat the same process as before with removing only the high points. Finally, reorient the sphere to the final axis to remove the last high points.
Repeat this step if not perfectly round. Remember to only remove the high portions of the sphere. If you cut into the sphere further then that you will remove too much causing more and more material to be removed.
Step 10: Sand Sphere
Once round, sand the sphere smooth by following the same pattern of orienting the sphere through the three axis.
Step 11: Apply Finish and Admire Your Work
You can apply any finish you like. I used spray lacquer as it was easier than most anything else.
What are your favorite finishes? What tips and ideas do you have for making things out wooden spheres? Anything I missed?