We present a new and innovative method to generate Contour Parallel tool paths using Clothoidal spirals for 2.5D pocket milling. The tool paths generated by the proposed method are more suitable for High Speed Machining compared to the traditional tool paths. Mechanical parts, such as those in Aerospace industry, Mold and Dies industry, etc require large volumes of milling operations. Modern High Speed CNC Machines are used in making of these parts. Although the High Speed CNC machines can provide very high spindle speed, due to various reasons, it has not been possible to use their High speed capabilities to their full extent. Two of the main reasons being, complex pocket geometry and complex tool path geometry. Most pockets are made up of sharp corners. In the traditional contour parallel pocket milling tool paths, as the cutting tool approaches these corners, they have to undergo a sudden change in directions and the acceleration of the tool has to be instantaneously decreased. Also, there is an instantaneous increase in the chip volume and the resultant forces acting on the cutting tool. In our proposed method we smooth these sharp corners of the traditional tool path by using Clothoidal spirals. The Clothoidal curves which have traditionally been used for Highways and Rail track design, have an unique property, according to which, the curvature of the Clothoidal spirals varies linearly with the length of the curve. By using these curves of uniformly varying curvature, we reduce the magnitude of the sudden direction changes that the cutting tool has to undergo at the sharp pocket corners. The cutting tool is subjected to lesser resultant forces and has a comparatively uniform acceleration. Machining time is also expected to be reduced by our proposed method.
| Identifer | oai:union.ndltd.org:NCSU/oai:NCSU:etd-05212004-114758 |
| Date | 21 May 2004 |
| Creators | Pamali, Abhinand P |
| Contributors | Dr.Yuan-Shin Lee, Dr. Robert Young, Dr.Stephen Roberts, Dr. Ezat Sanii |
| Publisher | NCSU |
| Source Sets | North Carolina State University |
| Language | English |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://www.lib.ncsu.edu/theses/available/etd-05212004-114758/ |
| Rights | unrestricted, I hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to NC State University or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report. |
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