The principle of customizing the size and consistency of ice in an air cooling flake ice machine primarily involves controlling various parameters in the ice-making process. While the specific design and mechanisms may vary among different machines, the general principle revolves around adjusting key factors to influence the characteristics of the produced ice. Here's an overview of the principles involved:

1. Drum Speed: The refrigerated drum or evaporator in a flake ice machine is a critical component. By altering the speed at which the drum rotates, you can control the rate at which ice forms on its surface. Slower drum speeds typically lead to thicker ice flakes, while faster speeds result in thinner flakes.

2. Water Flow Rate: The rate at which water is sprayed onto the drum can be adjusted. This parameter affects the thickness of the ice flakes. Higher water flow rates generally produce thinner flakes, while lower flow rates lead to thicker flakes.

3. Scraping Blade Pressure: The pressure applied by the scraping blades or auger against the drum's surface plays a role in determining the ice's thickness and consistency. Higher pressure often results in thinner flakes, while lower pressure tends to yield thicker flakes.

4. Temperature Control: The temperature of the evaporator or refrigerated drum can be modified. Lower temperatures typically produce harder, thinner flakes, while slightly higher temperatures result in softer, thicker flakes.

5. Harvesting Cycle: The duration and frequency of the ice harvesting cycle can be adjusted. This can influence the size and texture of the ice produced. Longer harvest cycles may produce thicker ice flakes, while shorter cycles can result in thinner flakes.

6. Variability Control: Some advanced flake ice machines offer controls to vary the ice quality to meet changing demands. This allows operators to produce ice with different characteristics based on specific requirements.

The customization process involves experimenting with these parameters to achieve the desired ice texture and size. Operators often fine-tune these settings based on their experience and the specific needs of their application.