A Novel Multipin Positioning System for the Generation of High-Resolution 3-D Profiles by Pin-Arrays

This paper extends pin-tool research by investigating a new method to accurately position high-fidelity pins in an array, with each pin uniquely positioned under computer control. The resultant tool is a reusable prototyping system for the rapid generation of three-dimension (3-D) profiles using CAD extracted data, with application potential in a variety of manufacturing processes. A control assessment identifies a combination of array-addressing, latching positioning hardware, and a combined "setting platen" pin-position feedback and drive as an appropriate technique for pin control. The novel platen motion strategy is capable of moving thousands of pins with a single drive motor. The system incorporates latching "locks" that operate on the "tail" of a new two-part "header and tail" pin design. Key to the lock strategy is the application of shape memory alloy actuators in a back-to-back configuration; the response of this material to electrical input is quantified and applied to achieve the unique lock design. Multiple locks combined into a demonstrator position headers to an accuracy of +0.09 -0.05 mm. The mounting pitch of the prototype system permits the use of 1.0 mm section pins. An extension to the design ultimately allows a 15 000 pin-array to be positioned in ~3 min.