Development and evaluation of metal rolling machine for small-scale manufacturers
The global drive toward intermediate technology and sustainable development motivated the development of sheet metal rolling machines for small-scale artisanal manufacturers. This paper presents the design, construction and evaluation of a sheet metal rolling machine for small-scale enterprises. The machine consists of three rollers; a rigid forming roller, a free floating roller and a drive roller arranged triangularly with two handles for shape-rolling. The rollers were made of galvanized metal pipe, 1,050 mm long, 76 mm diameter, each approximately, 3 mm thickness; a driving shaft 1,220 mm long, 16.6 mm diameter and 4 pieces of mild steel washers to provide support to shaft and also to limit the bending stress on the rollers. The entire system is mounted on a metal frame made from angled-iron bars which were secured in place with 19 mm bolt and nuts. The clamping and folding bearing blocks are 120 mm thick, the throat width is 1,200 mm, and maximum length capacity of the machine is 1,050 mm. The best roller aperture for material tested is 5.5 mm and maximum bend radius of 2.5 mm. The maximum length of material that gives the best circular shape is 620 mm. The average percentage acceptance of the machine by the artisan is 70.59% (n=24) indicating that the technology is acceptable. Fifteen percent of the welders and 40% of tinsmiths are well acquainted with the functions of the machine. A total of 73.53% (n=26) of the respondents are not acquainted (technology awareness) with the shape rolling technology while 26.47% (n=9) have a fair knowledge of the use of such machines in metal rolling. The whole machine has a very small footprint, making it ideal for the home workshop and small factory alike.
Keywords: metal rolling, bushing, bearing block, capacity, bending load