Some common signs of low lubrication oil in a shot blasting machine include:

1. Increased friction and heat: Insufficient lubrication oil can lead to increased friction between moving parts, resulting in higher temperatures. You may notice excessive heat radiating from the machine or hot surfaces on various components.

2. Unusual noises: Low lubrication oil levels can cause metal-to-metal contact and create unusual noises such as grinding, squealing, or knocking sounds. These noises indicate that the moving parts are not adequately lubricated.

3. Increased wear and tear: Inadequate lubrication can accelerate wear and tear on the machine's components. You may observe excessive wear on bearings, gears, and other moving parts. Increased maintenance and replacement of parts may be required.

4. Reduced performance and efficiency: Insufficient lubrication affects the smooth operation of the machine, leading to decreased performance and efficiency. The machine may experience reduced speed, decreased productivity, or even unexpected breakdowns.

5. Overheating of the lubrication system: Low lubrication oil levels can cause the lubrication system to overheat. This can be identified by the presence of excessive heat or smoke emanating from the lubrication system.

6. Increased energy consumption: When the lubrication oil is low, the machine's components experience higher friction, requiring more energy to operate. If you notice a significant increase in energy consumption without any apparent reason, it could indicate low lubrication oil levels.

7. Lubrication system alarms or warnings: Some shot blasting machines are equipped with monitoring systems that detect low lubrication oil levels. These systems may trigger alarms or display warnings indicating the need for oil replenishment.

If you observe any of these signs, it is crucial to address the issue promptly by checking and replenishing the lubrication oil in the shot blasting machine. Regular monitoring and maintenance of the lubrication system will help prevent such issues and ensure the machine's optimal performance.