A hydraulic press and pull machine comprising of a frame, cylinder and piston, two threaded studs, hydraulic pump and hose, pulling clamp and a workpiece support was designed, fabricated and evaluated. The machine is manually operated. The maximum shear force, maximum bending moment and maximum displacement of the machine workpiece support were determined as 74.9491N, 16.6335N-m and 4.367e3mm for a simulated load of 1000N. Maximum axial, bending and torsional stresses were also determined as 0.00359, 701998 and 0.00653N/m2 respectively. performance of the developed machine was determined using seven bearings of bore diameters 24, 30, 40, 50, 65, 80 and 100mm respectively, fitted into seven corresponding shafts with shaft deviation of ±0.001mm and dismantled afterwards using three different methods: traditional hammering, the developed manual hydraulic press and pull machine and already existing electrically powered hydraulic press. The results of the experiments showed that traditional hammering is the most time consuming method of mounting and dismounting force fits, followed by the use of the developed press-pull machine while electrically powered hydraulic presses are the fastest.The machine which was fabricated with local materials will reduce the time and stress associated with installation and removal of bearings, and other forms of force fits in machine assemblies. Hence, leading to an overall improvement in the standard of machines/equipment fabricated in Nigeria

This paper assessed the suitability of PET powder produced by crushing used plastic bottles as 3D printing feedstock. Characterization of the powder was done through determining its flow property, coefficient of friction, bulk density, flexural and tensile strengths and compared with those of ABS, PLA, PVA, Nylon and HDPE which are used conventionally 3D printing of plastic parts. Two grades of PET bottles were used in this study: grade one which is designated PET1 with intrinsic viscosity values ranging from 0.78-0.80 (used for water bottles) and grade two which is designated PET2 with intrinsic viscosity values ranging from 0.80-0.85 (used for carbonated drinks bottles). The results of the tests performed showed that PET1 has bulk density, coefficient of friction, flexural strength and tensile strength values of 0.16 g/m3, 0.43, 82.1 MPa and 63.4 MPa respectively while PET2 has bulk density, coefficient of friction, flexural strength and tensile strength values of 0.15 g/m3, 0.22, 82.7 MPa and 57.8 MPa respectively. The Experimental results show that both PET1 and PET2 have very good flow property, and are suitable for 3D printing. This study solves two major problems: plastic waste management and availability of locally produced 3D printing feedstock, which is currently the greatest challenge of 3D printing in Nigeria. Keywords— 3D printing feedstock, Characterization, Intrinsic viscosity, PET powder.

A multipurpose railroad hand truck comprising mainly of a frame, swinger arm, connecting rod, crank shaft, gears, wheels and brake was designed and fabricated to reduce the cost of material handling in small scaled manufacturing industries. The frame and other major components of the hand truck were fabricated with mild steel bars, shafts and sheets while the guide rail was constructed using 50mm by 50mm mild steel angle bar. The hand truck is hand paddled and requires no prime mover (electric motor, IC engine, etc.), hence incurring minimal operational cost. The hand truck will be used to convey tools, materials and work pieces from one part of the workshop to another on guide rails. Results of its performance test indicated that the hand truck can carry loads up to 250kg. All materials used for the fabrication were sourced locally.

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