Polycutter in the field

In different regions of our country, the soil is cultivated in different ways. Soil and climate conditions naturally leave their mark on the designs of small-scale mechanization tools developed by owners of household plots. Some build micro-tractors and motor blocks designed for use with a plow; others build motor tillers.

Our reader from Sverdlovsk Oblast, A. Gordin, offers a version using a set of cutters mounted on a homemade side trailer for the Tula-200 moped. The advantages of such a working tool are that it has a large working width and loosens the soil well.

My till implement, it seems to me, is attractive in that the moped does not have to undergo major modification. All you need to do is remove the rear wheel and mount it on the side trailer shaft. And slightly lengthen the drive chain, because the wheel moves back from the fork, and the rear cross tube of the trailer is attached to the fork. The front cross tube is inserted into the Tula frame in front of the engine and is hinged to it.

The trailer running gear is a hollow shaft resting on the lugs of the frame’s longitudinal tubes and secured in them with clamps.

Mounted on the shaft are: wheel hubs with No. 206 bearings and spacer bushings, a double-sprocket for driving the working tool (its housing is similar in design to the left wheel hub), a drive sprocket, and a rotary tiller lift pedal.

The latter’s frame is welded from tubes and steel plates and is mounted on the trailer at three points. It carries the rotary tiller — a block of bushings with curved, sharpened tines welded to them.

The rotary tiller is assembled as follows (Fig. 4). Tubular shaft 19 is fitted with bushings 20 with tines, hub 21 with a sprocket, No. 210 bearings and their half-housings 22, between which links 23 with bell cranks 24 are clamped. The assembled block is pre-tightened with screws 27, the left one of which is fitted with sprocket 28 (when working dense soil, the number of its teeth can be reduced from 8 to 7 or even to 6).

For even rotary tiller operation, the tines should be arranged around the circumference so that they enter the ground in pairs on the right and left. After that, screws 27 are finally tightened and the bushings are secured to the shaft: seven holes are drilled for bolts 25 and one for the torque-limiting bolt 26.

The rotary tiller is placed in frame brackets 16, chains 29, 33, and 34 are fitted, and their tension is adjusted with intermediate shaft screws 31 and links 23. Bracket 17 with depth-limiting wheel 18, which sets the soil working depth, is installed on the right end of frame 16. Pedal 35 is fitted, and the rotary tiller is balanced with a spring.

The assembled mechanisms are checked, lubricated, and turned by hand with the unit raised. You can start the engine and begin cultivating the household plot. Movement should be in circles, and the working tool’s speed should be kept steady with the throttle; otherwise the tillage will be uneven. On dry soil, uniform tillage depth is achieved by installing two more depth-limiting wheels 18 on the ends of frame tubes 16.

On turns, when driving over an obstacle, or when the engine is overloaded, the rotary tiller is raised with the pedal. If engine power is insufficient, the outer cutters are removed. When moving from one plot to another, chain 34 is removed and screws 11 are moved to sprocket 7.

It may happen that, to increase the unit’s passability, the wheels will need to be locked together.

Turning a moped into a tractor no longer surprises anyone: home-built motor transport has long been a common base for such designs. But being able to easily turn the tractor back into a moped after finishing work in the vegetable garden or orchard is, without doubt, a design breakthrough by our reader A. Gordin.

Indeed, is it really necessary to multiply engines on one’s farm? Is a separate self-propelled agricultural unit needed? Would it not be better to have a universal drive for various working tools that ease labor on a household plot?

We invite skilled builders who have made such designs to share their experience: send photographs, drawings, and descriptions of the universal small-scale mechanization tools you have created. We also await such materials from leaders of agricultural design clubs and young technicians — participants in the magazine’s “Small Mechanization” competition — for the best designs of auxiliary mechanisms, attachments, and hand tools for work on household plots and in school experimental farming.

«M-K» 10’84, A. GORDIN