- Joined
- Jan 22, 2014
- Messages
- 578
4” Hollow Sphere
I’ve been thinking about making a hollow vessel in metal for some time now but I’ve decided that it just can’t be done safely without CNC. But a hollow “box” is possible if you make the project in two-pieces like one I made many years ago, in wood.
My plan was to create a ball in 6061 aluminum (4”X 6” billet) and soon found that I had to make a custom tool to cut a ball large enough for this project. I cut a 4” ball, parted it into two pieces and worked each ½ into matching twins that fit together. To hollow the inside, I used step cuts while carefully measuring the wall thickness to ensure that I didn’t cut through (1/4”). Once this was complete, I decided to make jewel-like cuts to provide maximum light refraction using my set of ball-end mills.
I wanted to tease viewers to wonder what’s inside so I made ”windows” all around it. I tried something new and skewed the rotary table about 40*. The skewed table along with the round form makes it appear to have lazy “S” windows, when in fact they are straight cuts. I fashioned a small handle from the top tenon to invite viewers to lift the lid and look inside. One of the bonuses I hadn’t considered is it is not only pleasing to the visual senses, but it turned out to have audio characteristics because it chimes a bit when opening and closing the lid.
This project took many steps, many set-ups and a lot of detail work to complete. I made nearly 700 precision cuts on it (650 inside alone) and many hours of finish work. When assembled, you can barely notice the part line. I mounted it on a base of natural-edge Mesquite wood. Peeking inside draws attention because the light passing through it gives it a very special, one of a kind look.
Factoid: What started as a 7 pound billet ended up weighing less than 1 pound. I nearly filled up one 33 gallon trash can with swarf and then recycled it for a couple of bucks.
Equipment:
Grizzly G0602 with custom 4” Ball Turner
LMS Mini Mill w/ 4” rotary table and angle plate
ER25-5/8” Collet adapter plate
Set of Ball-End milling tools
I’ve been thinking about making a hollow vessel in metal for some time now but I’ve decided that it just can’t be done safely without CNC. But a hollow “box” is possible if you make the project in two-pieces like one I made many years ago, in wood.
My plan was to create a ball in 6061 aluminum (4”X 6” billet) and soon found that I had to make a custom tool to cut a ball large enough for this project. I cut a 4” ball, parted it into two pieces and worked each ½ into matching twins that fit together. To hollow the inside, I used step cuts while carefully measuring the wall thickness to ensure that I didn’t cut through (1/4”). Once this was complete, I decided to make jewel-like cuts to provide maximum light refraction using my set of ball-end mills.
I wanted to tease viewers to wonder what’s inside so I made ”windows” all around it. I tried something new and skewed the rotary table about 40*. The skewed table along with the round form makes it appear to have lazy “S” windows, when in fact they are straight cuts. I fashioned a small handle from the top tenon to invite viewers to lift the lid and look inside. One of the bonuses I hadn’t considered is it is not only pleasing to the visual senses, but it turned out to have audio characteristics because it chimes a bit when opening and closing the lid.
This project took many steps, many set-ups and a lot of detail work to complete. I made nearly 700 precision cuts on it (650 inside alone) and many hours of finish work. When assembled, you can barely notice the part line. I mounted it on a base of natural-edge Mesquite wood. Peeking inside draws attention because the light passing through it gives it a very special, one of a kind look.
Factoid: What started as a 7 pound billet ended up weighing less than 1 pound. I nearly filled up one 33 gallon trash can with swarf and then recycled it for a couple of bucks.
Equipment:
Grizzly G0602 with custom 4” Ball Turner
LMS Mini Mill w/ 4” rotary table and angle plate
ER25-5/8” Collet adapter plate
Set of Ball-End milling tools
