150°C and abrasive metal parts: linear bearing in 3D printing machine for metal parts

Profile

• What was needed: drylin linear bearing technology
• Requirements: Smooth operation in the 3D printer at temperatures of 150°C and abrasive metal particles in the environment; lubrication-free; high precision and low vibration
• Industry: 3D printers, aviation and aerospace
• Success for the customer: Thanks to excellent temperature and wear resistance properties, high accuracy and freedom from vibration, and the absolute absence of lubrication, drylin bearings represent a reliable and cost-effective solution.

Metal parts measuring up to 20 x 6 x 6 metres are produced with this XXL 3D printer for the aviation industry.

Problem

Aerosol, a company active in the aviation industry, was involved in the development of a highly ambitious new laser-based 3D printing machine: the largest and fastest metal powder bed 3D printing machine in the world.
The machine prints metal parts measuring up to 20 x 6 x 6 metres at speeds up to 10 times faster than current 3D printing systems. At the centre of the process is a high-performance laser that melts thin layers of ultra-fine metal powder until a 3D geometry is formed. The metal powder coating must be applied evenly to a thickness of just 50µm. The desired component is then created layer by layer.
The rails for guiding the laser must therefore function perfectly under extreme temperatures of up to 150°C and under the influence of the finest abrasive metal powder particles in the environment. The system need not also be lubricated, as the fine powder will otherwise settle on the linear system and impair or completely prevent its function. The system should also be very strong, as any vibration reduces the quality of the powder layer and affects the mechanical specifications of the part to be produced. Conventional bearing systems were therefore not suitable for this harsh environment.

Solution

A drylin rail system was the perfect solution for this application, which now travels over a length of 3.2 metres in the XXL printer. The excellent temperature and wear resistance properties of the polymer bearings enable a long-lasting solution that is easy to maintain in this harsh environment. The design of the bearings enables operation in "dirty" environments and is ideal for use with metal powders.
The quality of the powder layer is extremely important, as any defect in this layer causes a defect in the part. Adjustable drylin pillow block bearings have been used to achieve a high degree of accuracy and freedom from vibration. However, the biggest advantage of the drylin system in this application was the fact that no lubrication is required. This not only prevents the metal powder from blocking the linear guide. The risk of contamination of the metal powder by any lubricating grease is also completely avoided by the "dry" rail system.
Finally, a long service life could also be guaranteed with the product solution. The requirement for the rails in the metal 3D printer was to function continuously for at least two weeks under the specified environmental conditions.
This, together with the other advantages mentioned, ensured that the product solution with polymer bearings was the only reliable and cost-effective solution for our application.

The 3D printer works with a high-performance laser that melts thin layers of the finest metal powder.

For the linear guide, the customer relies on drylin polymer bearings, which represent a reliable and cost-effective solution for the application.