Computer support for the shape formation of helical surfaces with a disk tool

An analytical description of the process of making helical surfaces with a disk tool with a substantiated definition of the objective function is proposed. By analogy with coordinate metrology, it is proposed to adopt a minimum tolerance zone as an objective function. This allows to specify the required solution error and eliminates the need to use normal lines or tangents to the profiles. An example of calculating the profile of a helical groove of a twotoothed end mill, performed with an error of 0.05 mm is presented. Keywords: helical surface, disk tool, computer support, optimization, minimum tolerance. [email protected]

Study and Application of Asymmetrical Disk Tools for Hard Rock Mining

In this article, the method of hard rock mining by undercutting or back incision using asymmetrical disk tools as an alternative to the milling method with the use of cutting tools was described. The results of modelling the penetration of a single asymmetric disk tool edge into an artificial and natural rock sample were presented and compared with empirical laboratory tests. The effect of stand tests for mining artificial rock samples using asymmetrical disk tools mounted on the rotating plate was presented. The tests were carried out on two unique test stands. The solution of an innovative mining head with a complex motion trajectory, using the asymmetrical disk tools, was presented. The innovative mining head especially developed at the AGH Kraków Department of Machinery Engineering and Transport for roadheaders, was presented. The results of preliminary field tests with the use of this mining head were also described.

Dynamic model of process of deformation of elastic rack of disk cultivator

The article presents the results of theoretical studies of the dynamic model of the process of deformation of the elastic rack of a disk tool of arbitrary shape, a system of differential equations in general and developed the corresponding program code in Mathematica software package. Taking the form of an elastic discus disk for an Archimedean spiral, when the functions of its boundaries are given in polar coordinates, where the parameters of the geometric shape a (spiral pitch), b (spiral displacement along the radial coordinate), h (elastic column thickness) are determined by its equivalent physical a mathematical model in the form of a rigid mathematical pendulum of length l, to the load of which are attached two springs along the axes Ox and Oz with stiffness coefficients kx and kz, respectively, which deflect it by an angle φ. The dependences of the stiffness coefficients kx and kz, the length l and the angle φ of the equivalent physicomathematical model of the elastic stand of the disc with the parameters of the geometric shape a=0.8 m, b=0 m, h=0.01 m on the values of Fex and Fez, acting on the free end of the rack along the axes Ox and Oz.

A new method for designing and machining air compressor screw pairs

Screw air compressors have been being used widely for 45 years. There are many research works on these machines, but there have been still many problems, especially on designing and machining their screw pair, to study. This paper focuses on gate screw profiling from the main screw profile and disc tool profiling for manufacturing the screw pair. The air compressor screw 3D model pair, designed by using the proposed methods, have satisfied the meshing condition. The disc tool 3D models created for machining the screws have also been tested in many ways, these testing results show high accuracy of the disk tool 3D model, which can be used in industrial manufacturing.

Implementation of Anti Forensics on Hard Drives Using the DoD 5220.22 M Method and British HMG IS5 E

The process of securing data is related to anti-forensic science, one of the anti-forensic techniques that can be used to safeguard data security, namely by deleting data on storage media. This study examines the implementation of data deletion using the DoD 5220.22 M and British HMG IS5 E methods, then compares these methods. The comparison of the two methods includes performance tests, forensic tests, and data recovery tests. The results of the performance test show that the two methods are strongly influenced by the anti-forensic tools used and do not provide a significant difference when applied using one of the tools. The results of the implementation of data deletion using both methods on the hard disk drive are declared safe to delete data, as evidenced by the extraction results in the forensic test using the Autopsy tool found files on the partition :F with the number of 252 files and on the partition :I with the number of 1 file and the extraction results from the test Forensics using the Recover My File tool managed to find files with the number of 102 files on different partitions, but all the files found in the forensic test process cannot be accessed. The results of the recovery test show that the safest method in the process of deleting data is the British HMG IS5 E method using the Active @ Kill Disk tool, as evidenced by all the results of the recovery process using three tools that do not find any files. Meanwhile, the application of the deletion method that is generally carried out by users, namely the shift + delete method, is declared unsafe, as evidenced by the results of the recovery tests conducted showing that the deleted files can be recovered 100% and can be reaccessed using recovery tools.