This research is to test the fatigue endurance of the material by using end bending of specimen. The testing material is S45C steel and forming to the standard size for testing. The specimens with a diameter of 8 mm required a different bending moment. It was found that the large bending moment affects the fatigue of the specimen. The specimen quickly damaged due to the high bending stress and there were a small number of load cycles. If the bending moment acting on the specimen was reduced to the bending stress decreased and the number of load cycles increasing. It was shown that the bending stress and the magnitude of the bending moment affected the fatigue of the material. Also the appearance of damage marks of the specimen will have a flaw around the fracture surface. Then the flaw will be enlarged until the specimen will be damaged by fracture.

The fatigue testing machine that uses the force of torsion is invented to be a compact machine that uses the torsion as the force in the test. From the tests it achieved the highest of 200 newton meters using pneumatics to test the metal materials i.e. the steel S45C molded in accordance with the JIS Z 2274 standard. To find out the capacity of the fatigue testing machine that uses the force of torsion with 8 mm 10 mm and 12 mm diameter test pieces the machine was tested with different levels of the force of torsion and the percentage of the deviation of the tests did not exceed the limit of + 10 percent. This research could reduce the cost of the procurement of the fatigue testing machine that uses the force of torsion and could be used in the instruction in the department of mechanical engineering faculty of engineering Rajamangala University of Technology Phra Nakhon in the future.

The purposes of the research were to create and efficiency validation of computer Assisted for the courses of practiced to reading Creating and Evaluating the Effectiveness of Computer Assisted Instruction Program Subject Engineering Materials Chapter 3-6 based standard and analyses the leaning achievement of the student after by using computer assisted instruction . The subjects in the study were 20. Diploma students enrolled in Rajamangala University of Technology Phra Nakhon. The Researcher using the experiment by let the students do until test before class And then study by using computer assisted instruction focused on practiced to basic turning . After that let students do the unit test again at the class and calculate to find out the efficiency of the computer assisted instruction. And analyzed the learning achievement of students after study. The research result revealed that the efficiency of the computer assisted Instruction was efficient in standard Moreover after learning achievement at significant level of 0.05.

The purposes of the research were to create and efficiency validation of computer assisted for the courses of practiced disassembly and assembly fuel injection nozzles of Diesel Engine based standard 90/90 and analyse the learning achievement of the student after by using computer assisted instruction. The subjects in the study were 11 second year diploma students enrolled in Mechanical Power Department Rajamangala University of Technology Phra Nakhon. The Researcher using the experiment by let the students do until test before class and then stUdy by using computer assisted instruction focused on practiced disassembly and assembly fuel injection nozzles of Diesel Engine. After that let students do the unit test again at the class and calculate to find out the efficiency of the computer assisted instruction and analyse the learning achievement of students after study. The research result revealed that the efficiency of the computer assisted instruction was efficient in standard 90/90. Moreover after learning achievement at significant level of 0.01.

This research aims to build the prototype of Pia-Salid (Snake-Skin Gourami) cleaner. At present Pla-Salid is one of economic animals and is also one of small medium enterprises in Thailand. Pia-Salid traders require to reduce cost in hiring and decrease time in production procedure in order to gain the most efficiency. For this reason this prototype was built. This machine consists of 7 main parts. They are as follows: (1) A drum with screw blade of external dimension 500 mm and 200 mm internal dimension 200 mOl pitch sieve pore in cylindrical shape with 500 mm dimension and 700 mm long. The drum also has a way in and a way out with 1100 mOl of total length. (2) A set of drum supports. (3) The structure that holds the equipment. (4) 10 injectors. (5) Motor gear and centrifugal pump. (6) Major and minor containers for water. (7) A set of drum pressers. Amount 380 kilogram of Pia-Salid was used the principal material in the test. The measuring instruments were a stop-watch and a 60 kilogram scale. The result found that the small fish has less transfer-rate than the bigger ones. It could be said that it depended on the size or the weight of the tested fish to resist the injection or the friction of the drum wall. And if the revolution was low the transfer-rate could not be reached the requirement but the cleanness was decreased. To find out the timing of transferring 20 kilogram of fish (8 fish per kilogram) five tested were done. The result showed that it took about 1.56 minutes. And then 60 kilogram of fish were tested it approximately took 4.25 minutes which calculated from the revolution at 12 rounds per minute (12 rpm) in finding a volume of the fish cleaning.