FIELD: devices for length cutting of logs into lumbers, mainly in the conditions of small private enterprises. SUBSTANCE: the fixture has a post close to the saw drive and a post distant from it, supporting rollers of the posts, guide frame moving on the posts, supporting members of the guide frame, members for attachment of posts to the chain saw tube, base guide board for the guide frame, lumber thickness adjustment mechanism. The fixture is provided with an additional post close to the saw drive. The post that is distant from the saw drive is made like a rod with a thread on one end, let through the hole in the saw tube and attached to the tube with the aid of nuts located on both sides of the tube. The other end of the post is let through a slider that is connected to the clip on the guide frame for movement along the post and fixing on it with the aid of a screw. EFFECT: ensured stability of the lumber thickness in its width, enhanced reliability of attachment of the posts that are close to the saw drive on the tube of the chain saw, expanded range of used chain motor saws, reduced overall dimensions and mass of the fixture, enhanced precision of cut lumber, enhanced convenience of use, enhanced precision of lumber cutting, enhanced capacity. 20 cl, 16 dwg
