MINI - TRACTOR STUDENTNo, the headline is not a hoax. And not even the “joint work of members Kota, led by a talented teacher and organizer of technical creativity of rural children”. It is a workable mini-tractor is really created (and after extensive field testing has sent explanatory material about their design in the journal “modelist-Konstruktor”) 16-year-old Sretensky guy — Andrey Bobkov.

Multi-page description of a homemade machine-a helper is almost required edit processing. Slightly more complicated was the case with sketches. In a letter to the editor, the author asked to apologize for possible inaccuracies, inconsistencies with the generally accepted rules (with drawing, he says, he “not quite good”). I had something to help. The result is a material, which we offer to our readers.
Like many, I am a constant subscriber “Model construction”. It is not surprising that ideas, technical solutions, published in the journal, sunk into the soul. And then, complete with its own considerations, the advice of experienced farmers, they are embodied in real design “Yaroslavets”.
Mini tractor turned, that is, on all hundred! But send material about him, not in order to become “famous”. No, I just want to show what can (and should) do in their 15-16 years, if the family budget does not allow to buy even domestic walk-behind tractor MTZ-0,5, not to mention the acquisition of the Japanese miracle technology of the type “breath of Kubota’s artistry”.
On the creation of mini-tractor (MT) took almost two years. Of them half the time “ate” the choice of design, wanted a more or less suitable engine, other complex assemblies of parts, their arrangement… Came sometimes to despair and not to send it all somewhere far away! But then intervened some inner voice saying, what are you a wimp, home state has requested! And the mother (live without a father) has inspired the neighbors did not shrink back.
And how much effort (and, of course, patience) required the final development resulting in the alteration engine cooling (here meaning the cylinder-piston group from the “poscache” PD-10U instead of “regular” IZH-49), and the need to increase the gauge of the rear wheels! But now my “Yaroslavets”, in recognition of the villagers— good farm machine “is a truly classic layout”. Wheel formula “4×2. Rear axle — leading, front — driven (see ill.).
Engine (power unit IZH-49) located in front of the MT on the crossbars welded (no matter how hard electromotoare, and to master it, it is possible the student) to the part of the motor frame, taken from the “mother” of the motorcycle. They say that this design is considered appropriate for obtaining a more uniform distribution of mass MT, better cooling, etc.
The torque from the engine is transmitted to the intermediate shaft. This sprocket Z,, z2 and circuit PR-15,875. Intermediate can simultaneously serve and PTO. Because at the end it has a slot under the feather key and groove under the clamping bolt sleeve of the corresponding pulley or “workaholic-stars TION” (the latter in Fig. conventionally not shown). As for the z3, it together with the second circuit PR-15,875 transmits torque to z4 located at the entrance of the “open” rear axle, borrowed from the UAZ-452. Well as the leading (rear) wheels in the “Yaroslavets” employs fixed on the rod (dowel plus the clamping and axial bolts) “ATV” from the cultivator KIR-1,5. That is, in fact, and the entire drivetrain.
The layout of the mini-tractor
The layout of the mini-tractor:
1 — front wheel with pneumatic tire 5,0-10″, 2 – Farah, 3 — frame, 4 — steering gear 5 — engine, 6 — steering wheel 7 — gear shift lever, 8 — unit signal lights front, 9 — seat 10 — block signal lights rear ] 1 — rear wheel with pneumatic tire 6,0—16″, 12 — Carter the chain drive, 13 — pedal “brake”, “gas” and “clutch”.

Kinematic scheme of transmission
Kinematic scheme of transmission:
1 — front wheel (hoe KON-2,8 or motorized FDD, 2 PCs.), 2 — the engine (power unit) IZH-49 with the cylinder cooling from the PD-10UD, 3 — first step of chain- § tion of transmission PR-15,875,4 — intermediate shaft (PTO shaft), 5 — second stage chain transmission PR-15,875, 6 — wheel rear (from the cultivator KIR-1,5, 2), 7 — “open” . rear axle (UAZ-452) with a “planted” on him by an asterisk.

Frame design
The frame design of “Yaroslavets”:
1 — the front of the frame (welded from lengths of steel channel 65×36 mm), 2 — longitudinal rear half-frames (channel 100×80 mm, 2 pieces), 3 — inner rear articulated (585 mm section a steel angle 50×50 mm, 2 PCs.), 4 — bar weld-on steel (channel 100×80 mm).

Frame engine
Frame engine:
1 — used in the construction of the frame from the motorcycle, 2 — bolt, M10 (2 PCs.), 3 — nut M10 with washer Grover (2 PCs.), 4— weld cross member (steel angle 25×25 mm, 2 PCs.).

Intermediate shaft:
Intermediate shaft:
1 — front frame 2 — asterisk leading, 3 — star, led, 4 — intermediate shaft with the keyed socket on the end of a 5 — node 1680206С17 ball bearing, self-aligning, stretch sleeves (from the straw walkers “Fields” or potato harvester “Friendship”, 2 piece), 6 — a drum band brake.

Rear axle (bottom view, wheel removed)
Rear axle (bottom view, wheel removed):
1 — frame mini-tractor, 2 — “open” differential (from the UAZ-452) with riveted instead of a large bevel gear sprocket, 3 — node 1680208С17 ball bearing, self-aligning, stretch sleeves (from the straw walkers “Fields” or potato harvester “Druzhba”, 4 PCs.), 4 — axis with the threaded hole at the end (2 pieces).

Scheme a water thermosyphon engine cooling
Scheme water thermosiphon cooling dvigatelya:
1 – cooler with water-supply hoses. 2 – cylinder (from the “poscache” D-І0У I). 3 — a branch pipe (from 2.). 4 – carburetor with Vozduhoflotsky. 5 – engine IZH-49, 6 – damper (PD-10UD) is upgraded, 7 – magneto М27Г”

1 — pull longitudinal, 2 — front frame, 3 — steering gear (GAZ-53A), 4 — joint propeller (potato harvester MCC-2A, 2 PCs.), 5 — stand L-shape (steel angle 25×25 mm), 6 — wheel steering.

Front axle
Front axle:
1 — front wheel (sidecar FDD or hoe KON-2,8, 2), 2 — the axle shaft of the front wheel (2 PCs.), 3 — 8206 single thrust ball bearing (2 PCs.), 4 — bushing, support-rotating rack (45 Steel, 2 PCs.), 5 — support-rotating-stand (pivot) left with M16 thread on the end (Steel 40X), 6 — washer (2 PCs), 7 — castellated nut M16, 8 — cross (from the balancer of the front axle of the tractor MTZ-82 or cars type UAZ-452, Volga), 9 — transverse beam (steel pipe 42×3 square section), 10 — steering arm (from the GAZ-53 A), 11 — support-rotating-stand (pivot) with splined end (from the steering shaft of the tractor MTZ-82 “Belarus”), 12 — transverse thrust (from the steering control of the car GAZ-53 A), 13 — the lever of a steering trapeze (from the GAZ-53A).

The mechanism of linkage assemblies (option)
The hitch mechanism of aggregates (option):
1 – side panel (steel angle 50×50 mm, 2pcs), 2 – pin, 3 – Shia, 4 beams for fastening of mounted and trailed implements, 5 – Central thunder 6 – front-bracket, 7 – hole cross member with a nut in the middle of agricultural equipment, 8 – adjusting screw 9 -= rear frame of the mini-tractor, 10 – bolt M16, 11 – nut M16 (12pcs).
Front axle with suspension
Front axle with suspension.
Front axle? It differs little from those whose description is borne out repeatedly in the pages of “Modeller-designer” (see, for example, n log 3’91; 4’93). In fact, it is a steel crossbeam suspended on the axis (“Yaroslavets” — on the d-pad) to the frame of MT. To the beam with the two ends welded sleeve support-rotating racks made from strips of thick-walled steel pipe of appropriate dimensions. In the latter rotate mounted on ball-bearing pins that are connected to the axle shafts of the front wheels taken from the FDD or motorized cultivator CON is 2.8. With the right pin from the left (when viewed during the mini-tractor) differs only in that the upper part represents not that other, as the splined shaft (from “taxiing” MTZ-82 “Belarus”).
Steering is made on the basis of the steering mechanism and parts of the GAZ-5ЭА. However, I had to add two more u-joint from the potato harvester, the MCC-2A Yes L-shaped Desk to make it all fit into the overall design of the structure of improvised MT.
The Parking brake is almost the same as metopomancy system V. Yakovlev, whose description and drawings were published in the fifth issue of the journal for 1991. Moreover, the brake drum was the easiest to pin on the intermediate shaft (see kinematics). However, it is available is another option, when this drum, along with G4 will be riveted instead of large ionic gear “open” differential.
As previously noted, have the engine “Yaroslavets” other than the IZH-49, cooling. The replacement of “regular” cylinder others, “poscache” PD-10U. It’s easy to do so as the volume (350 cm3), and diameter (72 mm), and stroke (72 mm) are the same. It remains only to put more “water” radiator from a car (or even neskolko radiators from autotopies with less capacity), connect all appropriately between themselves (see ill.) rubber hoses — and please: get air instead of water cooling! Moreover, according to experts, special thermosyphon type. Works such cooling, it is necessary to tell a good one. Just to perform obligatory: to the water cooler was certainly above the top of the cylinder.
Authorities claim that the reliability of any machine (and agriculture in particular) is largely dependent on its constituent systems, components, and supporting structures. Frame mini-tractor is unlikely to be an exception. Because of that, and it is made “Yaroslavets”, welded, of powerful segments of the steel channel. Although, as shown, one could do here easier construction instead of welding to use to bond the parts together by bolting. As is done, for example, with the installation of the hitch mechanism units.
It is not excluded that someone my “Yaroslavets” may not seem so attractive. Moreover, when you provide the analysis of materials provided anyone will certainly appear comments-wishes. The same frame, like, too heavy, no reverse gear, and apparently, the MT does not possess the delights…
Yes, “Yaroslavets” not “Kubota”. But I have far more experience and knowledge at the disposal of the Japanese graduates. And rural mini-workshop — not upscale the plant. In addition, bind his hands and feet and deficit, and high cost. So MT with reverse gear yet (alas!) not for me.
And a hard worker “Yaroslavets” happy. Made him tow the truck. Though not as original as in V. Batysheva (“Modeler Konstruktor” No. 12,’93). But also: with a base of thick-walled steel pipes, wooden boards, “sewn” to the frame of a steel angle 25×25 mm. the Last — not from the newcomer “Progress”, and write-offs — from rakes CMO.
As for the plow, I opted for a design largely similar to that published in the tenth issue of the journal for 1991. Soul felt: to repent is not necessary. Although I am convinced that if you have the opportunity, you should purchase a maximum of adapting to your “Yaroslavets”, “factory” horse odnogolosy the plow.
And again. In the original version of my MT was conceived without lighting equipments. Supposedly, the field — not the freeway. But life soon radically changed the old “simplistic” plans. Had to urgently enter into the design of “Yaroslavets” and lights, and tail, and turn signal lights.
Saw: the limits of improving thee well established technology and there can not be. As they say, Lehigh trouble – the beginning!
A. BUBNOV, S. the place of meeting, Yaroslavl region.

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