International STEP-NC Demonstration of Closed-Loop Machining, Feed Optimization, and Measurement

On October 1-2, 2008, the STEP Manufacturing team (ISO TC184 SC4 WG3 T24) met at the Connecticut Center for Advanced Technology, in Hartford, Connecticut to demonstrate and discuss advanced uses of the STEP-NC AP238 standard. The highlight of the meeting was the live 5-axis machining of a titanium impeller.

Participants in the machining demonstration and other activities included Boeing, Connecticut Center for Advanced Technology, Concepts NRec, DMG, KTH Royal Institute of Technology, Mitutoyo, NIST, Sandvik Coromant, Scania, Siemens, and STEP Tools.

The meeting was very productive. We were able to show that we can mill an impeller using STEP-NC files containing models of the product, process, fixtures and cutting tools. We showed how the new information can enable on-machine feed-speed and tool life optimization, and we showed how the product tolerance information in STEP-NC can be used to implement closed loop machining using measurement devices such as probes and Faro arms.

Highlights include:

The complete flow of the machining, measurement, and feedback is shown below (click for full size):

Photo Gallery

Video overview of the machining demonstration and meeting.
YouTube Video

Video #2: less narration, more machining!
YouTube Video

Impeller test part machined at CCAT test Lab in the United Technology Research Center (UTRC) in Hartford, CT. Machined on a DMU-70eVo with cutting tools from Sandvik Coromant.

Cutting simulation view of impeller test part showing workingsteps, toolpaths, position, and cutting speed information.

Impeller test part cut from Ti6Al4V. Rather than cut everything at once, several blades were cut at a time for each of several audiences.

Complete STEP-NC Impeller Data [3.6M]
Includes geometry for starting and final pieces, fixtures, and tools, toolpaths for roughing, semi-finishing, finishing, and inspections, tool parameters, tolerances, datums, cross-section information, and optimized feed-speed parameters.