www.getwoodworking.com shows us how to make a lattice.
To turn the ball you will need a piece of timber the size of the required ball plus 2mm X diameter plus 20 – 30mm & a template to the required radius of the ball.
Step 1: Mount the Timber
Next mount the timber between centres and turn the timber to a round of the required size, this needs to be as accurate as possible to maintain the end size of the ball.
Step 2: Measure and Mark
Measure & mark the centre of the timber with a pencil, from this point turn the timber to the required radius using the template, it is important to make this cut as accurate as possible.
Step 3: Repeat
Repeat the same process on the other end of the timber again pay particular attention to accuracy the more accurate now the less work later. You should now have a ball with two stumps.
Step 4: Cup Chucks
For the next step you will need two “cup chucks” these are two scrap timbers turned to a sufficient diameter to hold the ball but not to impede the cutting of the grooves, and on the end of each there needs to be an inverted radius similar to that of the ball.
Step 5: Remount the Ball
We can now remount the ball remembering to cut the stumps back so as not to foul the tool rest this photo has not had the ends cut back yet this is to show the ideal way to remount the timber to maintain a good balance.
Step 6: The Ghost Line
When the lathe is turned on you will notice on the horizon a “ghost line” this is the only timber to be turn away. Keep rotating the ball and turning away the ghost line, the more you do this the more accurate the ball will be, but don’t turn any deeper.