One of the materials used in the building process is sand particle. Sand with uniform size is generally obtained from manual sifting processes that require a lot of human power and long sieving time, so a sand sieving machine is needed to minimize the use of human power and sieving time. The design is focused on sifting sand manually into sieving using a machine. The design of the machine uses design software to create a picture of the arrangement and working drawings of the components of the sand sieving machine. Based on the results of the trials that have been carried out, the machine can sift 5 kg of sand for 1.02 minutes and for 10 kg of sand can be sifted for 1.30 minutes.

EDM is one of the nonconventional machining processes when making workpieces with conventional machining processes is difficult. This process has been used effectively in machining hard, high-strength and high temperature materials such as high speed steel (HSS) materials. In this study, prototype of EDM machines was carried out with engine variables such as current (A), pulse on time (µs) and pulse off time (µs). The material used is high speed steel (HSS) material used in cutting tools such as turning tools and milling tools. Surface roughness and material removal rate are responses observed to determine the quality of material remaval. The quality characteristic of the surface roughness response is "smaller is better" and the quality characteristics of the material removal rate response is "larger is better. The purpose of this study is to determine the best process parameter level to achieve the required performance characteristics in the material removal process using prototype EDM machines using the gray relational analysis (GRA) method, three process parameters are selected such as current, pulse on time, and pulse off time. The taguchi 3 x 3 x 3 design is used as an experimental design.The best parameter level obtained is current 40 ampere, pulse on time 200 µs, pulse off time 20 µs.