GK-1 lawn mower

The grass collector is designed to gather mowed stems; it has a cage welded from metal rods onto which the cut plants fall. There is also a control mechanism for the collector: a chain drive, a gear reducer, and a pair of rods bent at a right angle that act like a crank. Deflecting the control-unit handle transmits motion via the chain, reducer, and rods to the cage; it tilts to the side and the stems spill off. Moving the handle back returns the cage to position.

The abbreviation in the title is clear: GK stands for lawn mower; the numeral denotes the cutting width—one meter. That is how, without great pretension, young technicians from the town of Mikhaylovka in Volgograd Oblast named their electrically powered machine. “Our mower,” the lads write, “last year took first place at the regional competition ‘Young Rationalizers—for the Village,’ and third at the All-Russian rally of student teams in Voronezh.”

Indeed, the unit is simple in design and maintenance, maneuverable, and—also important—built from scrapped parts and assemblies of old combine harvesters. As for the mower’s performance, the lads say: “In a day you can mow grass on an area of 2.5 hectares.”

The design of the lawn mower GK-1 is presented by Vladimir Ivanovich Popov, who leads the young technicians at the Mikhaylovka training and production combine.

In appearance it resembles a small cart with moped wheels rigidly connected by a section of one-inch pipe. Control is by a long handle—a “driver,” as the young designers call it. At the lower end of the driver, near the ground, is a sheet-steel frame set slightly forward with the units and mechanisms that take part in mowing: the motor, the cutting unit, and the drive.

The GK-1 uses a 500 W electric motor from a “Don” pump. It can be moved in slots in the frame to adjust drive-belt tension. The electric starting assembly is also from the pump and is mounted on the driver. (Remember: the mower handles must be insulated for safety, e.g. with pieces of rubber hose; and the grounding wire must be brought out!)

For the cutting unit we used knife segments and back pieces, plus finger sections from retired combine harvesters. The finger bar was made from the back of a forage-harvester knife, welding another such back at 90° on the rear side for stiffness. From a grain-combine header we used seven finger sections, bolted with M12 bolts to the finger bar as fixed fingers. From the same source we took parts for the moving—cutting—element: 13 knife segments, enough for about a meter of cutting width. Only the hold-down clips we designed and made ourselves.

The mower kinematics are straightforward: drive from the motor pulley to the driven pulley is by V-belt; both pulleys are mounted cantilevered on their shafts. On the outer surface of the driven shaft an eccentric, via a connecting rod, drives the reciprocating knife—motor rotation is thus converted to back-and-forth knife motion that cuts the grass; working stroke is 76 mm.

A support wheel at the edge of the cutting unit makes the mower easier to handle and helps keep cutting height constant.

«M-K» 6’81