摘要:
A barrel assembly for a composite structure includes a barrel of composite material, a first end ring, and a mid support. The barrel of composite material has a first end, an interior surface and an outer surface, and the first end ring is removably attached to the first end. The first end ring has a perimeter that is substantially congruent with the first end, and is configured to maintain a shape of the barrel. The mid support is removably disposed within the barrel, and has a plurality of spokes extending outwardly from a central hub to contact the interior surface, to maintain a shape of the barrel.
摘要:
A method is provided for assessing accuracy of positioning a NC machine having a spindle that is movable along each of at least two mutually orthogonal translational axes. The method Includes creating a master flame of reference relative to the translational axes by moving the machine along first and second translational axes. For each translational axis, coordinates of a target mounted adjacent the spindle are determined at a number of points along the respective translational axis. A linear fit of the coordinates is then calculated so as to create a set of mutually orthogonal axes defining the master frame of reference. Accuracy of positioning the machine in the master frame of reference is checked by positioning the spindle at a number of locations, measuring the coordinates of the target for each location, and determining errors in positioning of the machine by based upon the measured coordinates and machine-determined coordinates.
摘要:
Polychlorinated biphenyls are removed from oil by extracting the biphenyls into methanol. The mixture of methanol and extracted biphenyls is distilled to separate methanol therefrom, and the methanol is recycled for further use in extraction of biphenyls from oil.
摘要:
A barrel assembly for a composite structure includes a barrel of composite material, a first end ring, and a mid support. The barrel of composite material has a first end, an interior surface and an outer surface, and the first end ring is removably attached to the first end. The first end ring has a perimeter that is substantially congruent with the first end, and is configured to maintain a shape of the barrel. The mid support is removably disposed within the barrel, and has a plurality of spokes extending outwardly from a central hub to contact the interior surface, to maintain a shape of the barrel.
摘要:
Positioning errors of a numerically controlled machine and a fixture are related through a mathematical model to the statistical total error in the position of the machine tool, and maximum allowable amounts are assigned for each of the individual contributing factors to the total error. The relationship between the machine and fixture is checked by a probe mounted in the machine spindle. Functioning and alignment of the probe are checked with the probe. Global positioning accuracy of the machine is checked throughout a working envelope of the machine using a laser measuring instrument. A master coordinate system relative to the ways of the machine is created within the laser instrument by calculating a linear fit of machine position coordinates acquired as the machine is moved along each of two perpendicular axes of the machine, and the master coordinate system is used for the global accuracy and fixture accuracy checks.