Adam Maciak

The aim of the present study was to determine the effects of initial chain tension and feed force on the wear rate of chipper chain cutters in gasoline-powered chainsaws. Wear was assessed by measuring the tip radius as cutter dulling has a considerable influence on chainsaw performance. Tests were carried out for three feed force values: 15 N, 35 N, and 70 N, and for two initial tension settings—a tight chain and a slack chain. The tests also measured cutting efficiency per unit of kerf area. The experiments involved pine wood and were conducted on a specially designed test rig that maintained a constant feed force. The tip radius was determined by means of a microscope and computer image analysis software. Wear intensity over time was evaluated using the dulling coefficient. The results showed that the applied initial chain tension and feed force significantly affected the cutter wear rate, which was significantly higher at lower feed force values. The wear rate was also increased by lower initial chain tension, which can be explained by greater cutter deflection from the kerf plane.

The aim of this study was to determine the influence of initial chain tension, feed force, and wood hardness on the variability of the cutter’s deflection angle during petrol chainsaw operation. Cutting wood with a chainsaw is a complex process that has not been fully elucidated to date. During operation, the position of cutters with respect to the workpiece may vary. The situation is additionally complicated by the fact that chainsaws are powered by one-cylinder gasoline engines characterized by highly variable instantaneous rotational speeds. The experiments involved two types of wood (pine and oak), two initial tension values (tight vs. slack chain), and two feed forces (20 N and 80 N). The cutting process was recorded with a high-speed camera at 12,000 fps to determine cutter deflection angles, instantaneous speeds, and accelerations for all the aforementioned cases. It was found that at the lower feed force the cutter deflection differed depending on the initial chain tension, and a greater cutter deflection angle was observed in pine wood processing. It was also found that speed and acceleration in the Y axis were much lower than in the X axis. Additionally, the rear part of the cutter revealed greater speed variation in the X axis.

The paper describes a study on the effects of beam power and feed rate in the process of cutting fresh wood with a CO₂ laser on water contact angle on the cut surface. The study involved several broadleaved tree species (oak, birch, alder, plum, and apple tree) and one coniferous species (pine). Samples were cut with a Trumpf TLC1005 laser equipped with a TruFlow 6000 CO₂ resonator at a wavelength of 10.6 μm at three power output settings (1 kW, 2 kW, and 3 kW) and one feed rate (0.4 m∙min^− 1). Contact angle was measured by pipetting a drop of distilled water on the wood surface and recording the process with a camera. Subsequently, images of the drop were analyzed over one minute at 10 s intervals to determine changes in contact angle for each of the cases examined. It was not possible to measure the contact angle on saw-cut samples as the water was immediately absorbed, while water drops placed on laser-cut samples remained on the surface for over 60 s, with the contact angle decreasing over time for the examined species from an average of 90° to 40°. The higher beam power settings (2 or 3 kW) were found to be preferable for the hardwood species (oak, birch, alder, and apple tree). In turn, in the case of the softwood species (pine), the laser power output did not matter, as both at the low (1 kW) and high (3 kW) settings the drop did not spread over the surface quickly. Finally, the optimum beam power for plum tree wood was found to be 1 kW.

While lasers are widely used across various industries, including woodworking, few studies to date have addressed the issue of cutting fresh wood. In the present investigation, wood stemming from fresh tree branches was cut at different laser powers and beam travel speeds. A fiber laser and a CO₂ laser were used for the research. The cellular structures of the cut surfaces were examined, with some of them found to be covered with a layer of compacted, charred cells. This may be a favorable phenomenon, preventing the invasion of pathogens via the wounds caused by laser beam branch cutting in nurseries, plantations, and orchards.

Chainsaws with chipper-type chains are widely used in timber harvesting. While existing research on such saws assumes a continuous cutting process, the objectives of the present study were to determine whether or not that is true, as well as to measure instantaneous cutting forces and active cutting time (the time during which the chainsaw cutters are actually engaged with the wood sample). Tests were conducted on a special experimental stand enabling cutting force measurement with a frequency of 60 kHz. The test material was air-dry pine wood. The feed force range was 51–118 N. The chain was tensioned. The study revealed considerable variability in instantaneous cutting force, which was correlated with the rotational speed of the chainsaw engine, as indicated by frequency analysis. Furthermore, the process of cutting with chainsaws was shown to be discontinuous, and a cutter engagement time ratio was defined as the proportion of active cutting time to the overall time of chainsaw operation when making the cut. It was also found that active cutting time was directly proportionate to the applied feed force and inversely proportionate to the rotational speed of the chainsaw engine. The results may be practically applied to establish an optimum range of rotational speed that should be maintained by the operator to maximize cutting efficiency.

The research was aimed at determining and comparing uniformity and speed of dulling of chainsaw blades with chisels and semi-chisel type of edge during cutting of oak wood. In addition, the change in the cutting capacity of the surface along with the gap surface made for the tested chain saws was examined. The dullness measurement consisted of draw

The aim of the tests presented was to compare the temperature of the cutting system and cutting efficiency achieved when using pure rape seed oil and Pilarol oil (reference oil), for the sake of assessment of the usability of biodegradable rape-seed oil for lubrication of cutting system. The temperatures were measured with the use of a thermal imaging camera. The measurements were made with an electric chainsaw by Stihl, lubrication with rape-seed oil and Pilarol oil, dedicated to chainsaw (reference oil). It was concluded that given the insignificant differences in guide bar temperature and machining performance, pure rape-seed oil can be used for lubrication of cutting system.

The aim of the study is to determine the impact of the type of timber and saw chain types on fuel consumption and cutting efficiency during logging. A saw chain with chisel cutters and semi-chisel cutters and a saw chain with sintered carbide edges was used for the tests. The tests were carried out on two types of timber differing in hardness. Pine