Features

• Cut and Add On-The-Fly
• 12, ¼” ends under individual servo control
• 19 coordinated axes
• “Clean” fiber path
• 2 DOF in head
• DOF in part
• Highly contoured convex and concave parts
• Utilizes Accudyne fiber placement software
• Placement rates to 15 lbs/hr depending on contour

Situation:

Tier 1 supplier to aircraft OEM needed to manufacture a part at several hundred units per month. The part consisted of multiple laminates using a quasi isotropic construction and with significant geometry.

Problem:

Manual layup was deemed unacceptable due to cost, throughput and waste issues.

Solution:

Accudyne designed and built a 12-end, 6 degree of freedom fiber placement machine capable of complex geometries. On flat panels, the machine demonstrated adds and cuts “on the fly” at 30 m/min using 12 servo driven cutters, within 0.5mm accuracy. High speeds (>15 m/min) on highly contoured parts were accomplished using of linear motors on X, Y and Z, and highly dynamic water-cooled rotary motors. IR heating was used to introduce sufficient energy to tack the material at these speeds. In addition, Accudyne integrated a low-tension, refrigerated creel that was able to uniformly tension the tows, despite quick changes in velocity and direction.

In all, there were 31 servo motors, including 12 in the creel. Accudyne can program plies using its TPGEN software. This program takes CAD data for a ply surface and lays tows on the surface, starting with a no-strain (geodesic) path. Each tow is analyzed for buckling and wrinkling, and CAD data for each tow can be exported back into the CAD system for further analysis. Tow data was read by the machine-specific post and written to G-code for the Siemens 840D CNC.

As a part can contain both concave and convex surfaces, and radii of curvatures down to 50mm, collision prevention is a major issue. The fiber placement head is compact and has a steep draft angle. Even still, potential collisions can be frequent. Accudyne wrote a simulator program that allows the programmer to “walk around” the machine to get the best possible view of potential collisions. The path can then be manually edited for off-normal laying, or the software can automatically shift every path away from potential collisions.