Space cylinder at Saab Ericsson Space
SAAB Ericsson Space (SES) needed to find a way to industrialize the production in their potential Space program, i.e. the future Space Cylinder production to their customer EADS Alcatel. The Cylinder is to be used as a backbone structure in a satellite. The cylinder is 4 meters high and a diameter of 1,2 meter and weighs only 90 kg. The extreme low weight is possible by using composite materials with a thickness of down to 0,3 mm. The extreme materials put extreme demands on both the production process and the tools chosen.
The challenge is to drill in a composite material comprised of two thin composites layers separated by an aluminum honeycomb core. It is commonly accepted that this type of fragile structure is extremely difficult to drill in. No delamination from the drilling process is allowed in the CFC parts. Fiber fraying is only allowed in one layer with the size of 1*2 mm in square.
SES was one of the four end user participants in the European partly funded project ADFAST (Automation for Drilling, Fastening, Assembly, System integration and Tooling) that previously successfully had evaluated Orbital Drilling for different aerospace materials. One of the conclusions from the ADFAST project was that Orbital Drilling in CFRP coupons indocated longer fatigue life and that the static strength properties are equal to conventional drilling.
SES has after an extensive evaluation period chosen Novators portable Orbital Drilling unit, Orbital PX2.
Several different cutting tools where evaluated, including sophisticated tools with cutting tip inserts. Studies showed that when using Orbital Drilling™, readily available and relatively inexpensive diamond mandrels produced excellent results, and where subsequently incorporated into the production solution at SES.
The actual acceptance and pre-production test for the Orbital Drilling™ implementation at SES encompassed the drilling of 600 holes in the different hole sizes in the SES Qualification Model, all holes where drilled within tolerance.
The conclusions after using the Orbital Portable Orbital Drilling Unit at SES is that Orbital Drilling is a comprehensive method compared to conventional drilling methods. Today the Orbital Drilling™ method is a certified production process at SAAB Ericsson Space in Linköping, Sweden.