Effect of feed speed and wood species on roughness of machined surface.
In this study, the surface roughness values of planed beech-wood (Fagus L.), oak-wood (Quercus L.) and fir-wood (Abies alba Mill.) specimens were examined. The samples of beech-wood were cut from steamed bech-wood and from thermally modified beech-wood (220 oC). The test specimens were cut in radial directions. The specimens were machined by planing with two knives at 6, 12, 18 and 24 m/min feed speed. The cutting depth was constant with 2, 0 mm and rake angle of knives was 15o. The machining experiments were carried out using a single cutter-block of a Weinig Powermat 400. The cutter-block with a diameter of O 125 mm rotated at 6000 revolutions per minute (RPM). Surface roughness was measured from the radial face of each sample according to DIN 4768 (1990) by using Mitutoyo SJ-201 stylus scanner device. The values obtained were statically analyzed and the results were interpreted. Comparing the results of the surface roughness of four species, it has been obtained that the surface roughness increases when the feed rate increases. The surface quality of planed beech-wood, oak-wood and fir-wood samples were significantly different. The best quality of planed surface had samples of oak-wood and the samples of fir wood had the biggest values of surface roughness. There is no significant differences of the surface quality of thermally modified and steamed beach-wood samples despite the significant difference in mechanical and physical properties of the thermally modified and steamed wood.