Alson Manufacturing began business in 1968, and since that time has specialized in manufacturing complex aircraft parts, in particular aircraft skins. President and founder of the company, Al Schoellerman, stated that in addition to a variety of standard...and not so standard milling machines, Alson focuses on using innovative approaches to ensure quality parts. Alson has eleven NC machines and it's their large laser positioned NC multi-axis gantry mills that enables the company to be quite competitive in producing extremely accurate parts up to 83 feet long.

Alson has three of these mills and is installing a fourth. The latest is a high speed mill with a spindle speed of 10,000 rpms. The largest has a bed 14 feet wide and 120 feet long. Like the other gantry mills, it has two machining bridges. The Renishaw laser positioning system operates on three axes of both bridges and has a temperature controller that establishes all machining action in relation to 68 degrees Fahrenheit. Thus the combination of laser positioning and temperature compensation has eliminated any thermal effect from the machining operation. A further advantage of laser positioning is hat it provides better finishes by eliminating any rippling effect of the mill.

Because of the accuracy of the laser positioning system, by adding a Renishaw probe the machine acts like one big Coordinate Measuring Machine. On one ongoing project, which involves five-axis precision drilling of chin straps (members that hold the nose to the body of an airplane), tolerances are held to .004 inch over a 100 inches in length.

Before acquiring the large NC gantry mills, most of the "skins" were machined on 14 high speed cavity milling machines. Now with the large mills, only 4 of the cavity mills remain. This is due in part because of the accuracy of the NC gantry mills, and the fact that many of the skins are now more complicated. Cavity mills sometimes are used to prepare materials before machining them on the NC machine.

Alson also uses NCCS' NCL/IPV; a fully integrated NC verification module that can be accessed immediately as tool paths are being created. With NCL/IPV, NC verification becomes an integral part of the tool path development process and simulates, verifies and displays the metal removal process. The current model can be viewed from any orientation, cross sectioned, inspected, and compared to an existing solid model.

VARIMETRIX comes in handy for designing fixtures for the various parts. By being able to show the part in a solid model format, fixture design is much easier.