Bone fracture caused by various incident causes medical problems. Then bone restoration is required. Bone grafts can be used to solve this problem. One of the materials that can be used to produce bone graft is PMMA. PMMA requires to be combined with other materials to extend the solidification time. The material that can be used for bone graft material is sago starch. The main ingredient composition of Biocomposite [sago/PMMA] consists of sago: PMMA = 1 : 1 (w/w). The composition of the addition of MMA is 10% (v/w) of PMMA, this is to extend the curing time. Thus the material can be through from the chamber extruder to the nozzle. This research aims to obtain combinations of 3D Printer FDM Customized machine parameters for minimizing of error dimension. The 3D Printer machine uses pneumatic system to push the material from the container to the chamber and used screw extruder to push the material out through the nozzle. The experimental design method used a 2 k fractional factorial design, with 3 parameters, 2 levels and 3 responses. The experimental results obtained that the layer height parameter has a significant influence on the x-dimensional error. The optimization results obtained a combination of parameters to get the smallest error dimensions, the print speed is 25 mm/s, the layer height is 2.93 mm and the fill density is 20%. The results of optimization obtained that the x-dimensional error is 0.016, the ydimensional error is 0.069 and the z-dimensional error is 0.4539.

Kerusakan bangunan pasca gempa bumi menghasilkan limbah berupa reruntuhan bangunan (reusable material) yang tidak dimanfaatkan secara maksimal, sehingga memerlukan adanya pemanfaatan limbah reruntuhan bangunan tersebut sebagai material untuk membangun bangunan baru. Pada Penelitian ini dilakukan pengembangan material bangunan untuk mesin 3D Printer dengan memanfaatkan material sisa reruntuhan (reusable concrete material). Pembuatan kombinasi material menggunakan design of experiment berupa 2 k factorial design dengan menggunakan 2 faktor berupa variasi penambahan air dan superplaticizer, dengan 2 level berupa penambahan air sebesar 15 ml dan 25 ml dan superplaticizer 1 ml dan 2 ml dengan respon berupa kemampuan bentuk material. Hasil penelitian didapatkan bahwa run time 1 dan 2 mampu membentuk second layers tetapi run time 1 adanya ketidak-kontinuan material sedangkan run time 3 dan 4 tidak mampu membentuk second layers sehingga run time 2 yang memiliki kontinu dan kemampuan bentuk second layers. Kata kunci : Reusable Concrete, 3D Printer, Kemampuan bentuk.

Biocomposite material is a common material used in biomedical application. One of medical problems related to bone restoration which caused by accidents and injuries resulted in fracture bone parts. Biocomposite (Sagoo/PMMA) is being developed as a solution to solve that particular problem. In current research, tensile and flexural strength of sagoo/PMMA is tested and examined. There are correlation between value of tensile strength, value of bending strength, and curing time, with maximum tensile strength and bending strength were achieved by curing the specimen for 12 hours, with the maximum value of tensile strength is 3,337 MPa, and the maximum flexural is 2,653 MPa. The minimum tensile strength was achieved by curing the specimen for 6 hours with minimum value of tensile strength is 1,502 MPa, while the minimum flexural was acquired at curing time for 24 hours with minimum of bending strength is 0,536 MPa.

Stone is one of the C type materials from the eruption of Merapi volcano which is a commodity for the people around it. The process of transferring the materials to consumers uses a mode of transportation in the form of trucks. There are two types of trucks that be used, it are dump trucks and non-dump trucks. Non-dump trucks, the process of unloading material is used manually technique, using human power. In the unloading process, problems in the form of work postures were found to have the potential to cause musculoskeletal disorders. The method used in this study to analyze the working conditions using RULA. The results of measurements using the RULA method obtained a final score in the process of lifting the material, the maximum score is 7. Meanwhile, in the process of lifting stone material for transfer or unloading, the final score is 7. So it was concluded that the activity process has the potential to affect the health of workers. and further investigation and improvement of work processes are required as soon as possible.

Abstrak: Pengembangan Mesin 3D Printing Bangunan Untuk Material Sisa Reruntuhan Bangunan. Material reruntuhan bangunan dapat dimanfaatkan sebagai bahan bangunan yang digunakan untuk proses rekonstruksi. Teknologi yang dapat digunakan untuk melakukan rekonstruksi bangunan adalah teknologi 3D Printer FDM. Pada penelitian ini dikembangkan material untuk teknologi 3D Printer FDM dengan memanfaatkan recycle material yang tersusun berupa semen, fly ash, clay, superplaticizer dan air yang disebut recycle concrete, serta dilakukan optimasi parameter mesin 3D Printer untuk mendapatkan kombinasi parameter dengan error dimensi yang minimal. Penelitian ini dikembangkan mesin 3D Printer untuk konstruksi bangunan. Metode optimasi parameter menggunakan Fractional Factorial Design dengan 3 parameter dalam 2 level yaitu berupa print speed (100 mm/s dan 120 mm/s), layer height (6 mm dan 9 mm) serta kecepatan putaran ekstruder (30 rpm dan 40 rpm). Hasil optimasi didapatkan layer height berpengaruh signifikan terhadap error dimensi tinggi dan interaksi print speed dan kecepatan putaran ekstruder berpengaruh signifikan terhadap error dimensi tinggi, untuk mendapatkan error dimensi terkecil didapatkan dengan kombinasi parameter print speed sebesar 100 mm/s, layer height sebesar 6 mm, dan kecepatan putaran ekstruder sebesar 30 rpm dengan hasil error dimensi diameter sebesar 0,0671 dan error dimensi tinggi sebesar 0,0256.  Abstract: Building 3D Printing Machine Development for Building Ruins Residual Material. Building ruins materials can be used as building materials used for the reconstruction process. The technology that can be used to reconstruct buildings is FDM 3D Printer technology. In this study, materials for 3D Printer FDM technology were developed by utilizing recycle materials composed of cement, fly ash, clay, superplaticizer and water, it called recycle concrete. Optimization of 3D Printer machine parameters was carried out to obtain a combination of parameters with minimal error dimension. This research developed 3D Printer Machine for building construction. The parameter optimization method used Fractional Factorial Design with 3 parameters and 2 levels, it were explained by print speed (100 mm/s and 120 mm/s), layer height (6 mm and 9 mm) and extruder rotation speed (30 rpm and 40 rpm). The optimization results obtained layer height has a significant effect on high dimensional errors and the interaction of print speed and rotational speed of the extruder has a significant effect on high dimensional errors, to get the smallest dimensional error obtained with a combination of print speed parameters of 100 mm/s, layer height of 6 mm, and The extruder rotation speed is 30 rpm with a diameter dimension error of 0.0671 and a height dimension error of 0.0256.