The experiment consists of two stages; the pre-experiment and the mainexperiment.
I. Pre-experiment: in order to know influence of the kind of chain-saw machines and their mechanical characters on the vibration produced in the machine, vibrational acceleration for different kinds and for varying working conditions of chain-saw was measured under identically controlled conditions. And the following were made clear. The greater part of the vibration was caused by the piston reciprocation and the running of saw-chain on the guide-bar, and accordingly was governed by the engine horsepower and the type of generative power of chain-saw (see Table 2).
II. Main-experiment: in order to detect the factors giving influence to the vibration, vibrational acceleration was measured in the wood cutting under various conditions as shown in Table 1. The main point of interest was fixed on the influence of angle changes of chain-saw teeth.
The results obtained are as follows: (see Table 3)
1. The side width of square timber gave the largest influence on the vibration. Following that, the depth gauge was the largest factor.
2. Contrary to our expectation, the varying of each single angle of chain-saw teeth hardly gave any influence. Nevertheless, the influence of combinations of both angles was remarkable compared with that of each single angle.
3. After all, the below-stated may be given as a conclusion. Though the greater part of the vibration in the wood cutting was caused by the factors other than the both angles of chain-saw teeth, it is necessary to keep suitable degrees of angles and proper depth gauge in a given saw-chain, if we want to minimize the vibration.