Will need
To make a ball, we need to stock up in advance on the following materials, tools and means:
- 5 meters of polished aluminum foil;
- two metal bars with through holes;
- a square wooden rod;
- rubber mallet;
- steel hammer;
- lathe;
- a set of sandpaper of different grain sizes;
- polishing paste;
- cloth napkins, etc.
The process of making a foil ball
To make unwinding easier, place the foil roll on a flat surface, insert the edge under a square rod, the ends of which we insert into the holes of the metal bars lying along the edges of the roll.
Pulling out the foil sheet, we begin to crumple it and form a ball, trying from the very beginning to give it the correct spherical shape and compact the material as much as possible.
In total, we use 5 meters of foil to get the ball.
We begin to beat the ball, crumpled up from foil, from all sides with a rubber mallet, which ensures the safety of the still loose material, and at the same time allows it to be evenly compacted throughout the entire volume right up to the center. To speed up the process, we place the ball in a spherical recess of slightly larger diameter, made in a massive stand.
Next, we continue processing the ball with a hammer with a metal striker. At this stage, we complete the process of giving the ball the maximum possible sphericity and density, which we started with a rubber mallet.
We continue processing the ball with coarse sandpaper on a lathe, clamping it with two wooden stops installed in the chuck and tailstock. Here it is very important to fix the ball in the centers after each permutation with the least amount of runout.
We begin dry sanding the ball by hand using 40 grit sandpaper, then 80 grit and 220 grit.
Next, we proceed to wet polishing, using sandpaper number 360, 600, 1200, 2000 and 2500 in succession, periodically wiping the ball with a cloth.
We check the degree of sphericity using a special stand template. We finish polishing the sphere with polishing paste applied to a cloth.
After this operation, the ball acquires a mirror shine.
