The all-terrain vehicle "Bobik" is made according to the "perelomka" design, that is, it consists of two independent semi-frames that can independently rotate both in the horizontal and vertical planes. This design virtually eliminates the wheels hanging out on uneven surfaces and almost always all four wheels have contact with the ground. This increases the cross-country ability of the all-terrain vehicle, turning is carried out by turning the semi-frames, that is, the wheels themselves do not turn, they turn due to the skew of the semi-frames. Load capacity on land is about 300 kg, on water 200 kg. The curb weight of the all-terrain vehicle is 780 kg, the maximum speed is 25 km/h.
The frame is made of a profile pipe, the size of the front half-frame is length 165cm, width 80cm, height 26cm. The motor is located in front, which takes up 75 cm. For the frame, profiles with dimensions 40*40*2mm 40*20*1.5mm 40*25*2mm were used. The rear semi-frame is trapezoidal. Height 20cm, base width 81cm, side edges 90cm long, half frame height 26cm.
The outer skin is made of painted smooth sheet, which is attached to the frame with aluminum rivets. The all-terrain vehicle is small in size and capacity, the design was designed for minimally comfortable dimensions, and for an economical low-power engine, so the weight was reduced as much as possible without compromising the reliability and strength of the frame and transmission.
The base of the all-terrain vehicle is 183 cm; to attach the semi-frames, reinforced plates 10 mm thick are welded to their ends, through which the turning point is attached. The fracture unit is based on the steering knuckle of the UAZ front axle. The driver's seat (from the passenger Gazelle) is located on the rear edge of the front half-frame, one might say that it is almost in the center of gravity of the all-terrain vehicle. A full-fledged car battery is installed under the seat, the driver's seating position is high, conducive to overcoming off-road conditions and uneven terrain.
The transmission looks like this:
From the engine, torque is transmitted by four belts to the gearbox. The pulley on the engine has a diameter of 9.5 cm, the pulley on the box is 26 cm, it is installed on the support shaft to relieve the load on the box shaft, and rotates in a double-row bearing from the front wheel of the VAZ-2108. A splined bushing from the VAZ clutch disc is welded to the end of the driven pulley support shaft; this bushing includes the input shaft of the VAZ-2106 gearbox. The belts are tensioned by a roller on two springs, this roller also acts as a clutch, the length of the belts is 125cm. The generator drive is taken from the drive pulley on the engine by the fifth belt; the generator belt is from the D-240 diesel engine and almost all of its modifications.
Four belts in the drive were used to extend their life. In general, it would be possible to install one belt, but it would quickly wear out. The motor power is 9 kW, and for these belts the load should be 2 kW, just enough for four belts.
The output shaft of the box is cut off at the beginning of the splines, and the splines are fitted onto the VAZ cardan flange, while the cardan pipe is cut to the required size. The second end of the cardan is screwed by the cardan flange to the shaft of the chain gearbox, on which a sprocket Z=13 is welded, pitch 19.05 mm. The gearbox is made on the basis of the VAZ front hub and is attached to a metal plate, which in turn is screwed to the frame and can be shifted to tension the chain. From the intermediate shaft, the chain drive goes to the steering knuckle, on which a 41-tooth sprocket is installed, and from the knuckle the drive is distributed by cardans to the front and rear axles.
Driver's seat and controls. The brake pedal presses the brake cylinder through the rod (a UAZ clutch cylinder is installed). The clutch pedal is driven by a cable to the tension roller of the engine drive belts; by squeezing, the roller is pulled back and the belts begin to slip. The gas pedal controls the carburetor through a cable. The steering wheel and upper crosspiece are from a VAZ2106, the lower crosspiece is from an M-2141, the crosspieces are connected using a 20*20mm profile. The rake is also from M-2141. Under the steering wheel on the right there is a carburetor damper drive, and there is also a headlight switch, a horn button and a battery mass switch.
The cross-country ability of the all-terrain vehicle is good, although there may be a lack of differential locking, but this will significantly complicate the design and add weight. And so, in terms of cross-country ability, you can drive anywhere, even on water, the all-terrain vehicle floats, but a uniform draft is achieved if the rear part is loaded or there is a passenger, and there is a large roll on the front since both the engine and the driver are in front. The engine is rather weak, but it is enough for leisurely driving, and most importantly it is economical. But if the snow is more than 40 cm deep and loose, then the engine has a hard time. The belt clutch performed well, the main thing is that the belts are of high quality, the fake ones don’t last long, but with good belts the season definitely lasts.
It all started with the fact that they sent the old “Six” to the village where the parents moved to live. In general, to help with housework. The car was already old and served us faithfully for more than 20 years. But in the village you can’t go far with a rear-wheel drive, you needed something more passable to bring firewood, and if you need to, plow the garden, in general, a working tractor. But instead of a tractor, they came up with the idea of remaking a “six”, they found a rotten UAZ on the move in a neighboring village and for 9 thousand rubles they took the frame with the engine, but left the half-rotten body, and from this the construction began, and this is what happened.
In addition to purchasing an old UAZ without a body during construction, I also had to spend money on all sorts of small things. We spent money on working cylinders, pads, brake pipes, king pins, crosspieces, radiator, electrical wiring and many other small things. The all-terrain vehicle was built for about a month, Father built it in the evenings, and together on weekends. The usual tools were an angle grinder, welding, wrenches, and that’s what we started creating. Below in the photo is the same UAZ frame.
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Our old “six”, even before the refurbishment
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We didn’t take much photographs during construction; we didn’t think there might be anything interesting or new there.
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We made hydraulics and a snow blade.
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This is our all-terrain vehicle
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They also made a cart for it to carry firewood, and tried to plow on it. We go to the neighboring village to swim at the pond. Everyone is surprised by our design, interested in what and how, you won’t see such equipment in our area.
For residents of the Urals, Siberia, the North, and the Far East (that is, most of the country), the need for a vehicle such as an all-terrain vehicle is simply a vital necessity. There are many reasons for this: there are few good roads, the terrain is rugged, in winter there is deep snow for almost six months, and in the off-season and even in summer there is mud. I have always wanted to own a car that is not afraid of off-road conditions. Of course, a branded SUV, for example, a Niva with pneumatic tires (with them, this car is already twice as expensive as a regular one) is beyond my means. However (probably due to the maximalism of my character) the home-made all-terrain vehicle (of those that enthusiasts often assemble with their own hands), which can hardly be called a car, did not suit me either: I wanted to have something more.
The idea for an unusual car design was born quite unexpectedly: I saw a Zhiguli car standing on the street with a wheel leaning against it from a GAZ-66 being repaired nearby.
It was these wheels that could provide the qualities that made it easy to achieve high cross-country ability of the vehicle: low specific pressure on the ground, reliable tire grip, high ground clearance. Well, acceptable comfort would be provided by the body of a passenger car and its interior.
In addition, both parts of the plan were quite feasible, since they were not associated with any shortage. After all, every day more and more old passenger cars appear, which owners are ready to abandon and sell inexpensively. And in skillful hands, cars can find a second life: restoring any domestic car practically from scrap metal is within the capabilities of many do-it-yourselfers - for them it is only a matter of time and money for spare parts.
For me, creating an all-terrain vehicle was also a test of my own engineering and design skills. After appropriate analysis (and weighing the real possibilities), I decided that the most suitable body for an SUV is from a VAZ-2108 car. The one I received had its front end and underbody modified (a four-door body would have required more significant modifications). The engine compartment began to be lengthened. This was required by the wheels (of a much larger diameter than the standard ones) extending beyond the front clearance, and by the engine, which was now located along the axis of the car, like in the Niva and Classic, and not across, like in the front-wheel drive G8. But this extension did not spoil the appearance of the car - the transverse welds were covered with new wings and a hood. The latter was taken from the old Moskvich-2141, modified and straightened accordingly.
In the bottom of the cabin, a longitudinal opening was cut out in the middle, and a casing was welded above it, thus making a tunnel for the transmission units and components. Its dimensions are the same as those of the Niva, so I made the pattern for the development of the casing using the spread out soundproofing pads of this car. The front panel of the body (between the engine compartment and the passenger compartment) was reinforced with additional linings and struts.
The jeep fenders are mirrored in shape (in pairs: front and rear). To make them, first things first: cardboard templates, the edges of which joined to the body were carefully adjusted to its contours, and then, according to the templates, the fenders themselves. They are made of cold-rolled steel sheet with a thickness of 0.8 mm. I bent it by hand, so their surfaces are quite simple - conjugate planes. Rigidity is ensured by continuous (along their entire length) flanging of the free edge. The other edge (cut along the contours) of the fenders was welded to the corresponding body “eight” fenders, after which part of the latter in the wheel wells was cut off along the contour of the former.
The footrests (also mirrored in shape) are made of steel sheet 1.5 mm thick (with flanges for rigidity). They are welded to the lower flanges located at the joints of the sills and the underbody. The footrests themselves are made with steps; They do not reduce ground clearance, but add convenience. In addition, the steps cover the base space and create a more squat appearance for the all-terrain vehicle. To prevent the footrests from being slippery, their outer ribs are covered with rubber.
Bumpers, both front and rear, are made to cover the entire width of the car. Each of them is assembled from two emergency ones (taken from auto repair shops). The ends of the bumpers are connected to the fenders.
The engine is from a VAZ-21011 passenger car, derated to a compression ratio of 7.6, which allows it to use low-octane gasoline A-76 or AI-82.
As already mentioned, under the hood of the VAZ-2108 body, the engine, unlike the standard one, is now located longitudinally. To install it, we had to make a special transition subframe from a 2 mm thick steel sheet.
The transmission with its main units and components - clutch, transfer case, cardan drives - are used from the Niva car - VAZ-2121. The gearbox (four-speed) is from a Zhiguli (VAZ-21011), it connects to the Niva units without modifications. Since the base of the car has increased compared to the Nivskaya, a longer driveshaft had to be installed from the transfer case to the rear differential - from the Moskvich-412 car. From the differential, the torque is transmitted to the wheels by two axle shafts from the Niva car.
The transmission from the front differential to the wheels is by open shafts with constant velocity joints, also from the VAZ-2121.
Chassis - front and rear axles, as well as suspension elements: springs, shock absorbers, levers, etc. - all from the same VAZ-2121 Niva car.
To articulate the rear axle to the body, the longitudinal rods had to be lengthened by making inserts in some of them or welding one of the two.
The wheels (what car enthusiasts, and many professionals more often call rims) were taken from an old Polish-made Zhuk minibus. On their rims, home-made rims with flanges made of 2.5 mm steel sheet are also put on (with a “protrusion” to the outside) and welded. The width of the new wheel rim is 254 mm (10 inches), the mounting diameter is 457 mm (18 inches). The tires are secured to them with split rings, like on trucks. The mounting holes in the disks coincide in size and location with the “Niva” ones.
The tires themselves are tubed, diagonal, high-profile, low pressure (in the front - 0.8, in the rear - 0.7 atm.). The tires are the same in size and tread pattern (herringbone). like the GAZ-66 off-road truck.
Brakes - from Niva, without modifications, dual-circuit with vacuum booster; front - disc, rear - drum.
The steering is prefabricated: the mechanism is from a GAZ-24 Volga taxi, the drive is from a UAZ-469 car. This combination was not caused by any need, I just had these units in stock.
Electrical equipment is also prefabricated. Single-wire (with a “minus” on the body) electrical wiring - from a VAZ-2108. The generator and starter are from VAZ-2101. Headlight units - from VAZ-2106; rear light blocks - from VAZ-2108; front side and turning lights - from Moskvich-412; turn signal repeaters - from VAZ-2105.
(positions 2,4,5,7,9,10,11,12,13 - from the VAZ-2121 Niva):
1 - engine (from VAZ-21011 Zhiguli, derated); 2 - clutch; 3 - gearbox (from VAZ-21011 “Zhiguli”); 4 - intermediate cardan shaft; 5 - transfer case; 6 - rear driveshaft; 7 - rear axle; 8 - wheel (4 pcs.); 9 - front driveshaft; 10 - front axle; 11 - internal hinge of the front wheel drive (2 pcs.); 12 - front wheel drive shaft (2 pcs.); 13 - external hinge of the front wheel drive (2 pcs.)
1 - homemade wheel with rim dimensions 457-254/18″-10″ (diameter-width); 2 - front mudguard (tires 83); 3 - footrests (StZ, sheet in 1.5, 2 pieces - mirror image); 4 - tube tire, diagonal, lightweight, low pressure, sizes 457-320 (18″-12.6″); 5 - front signal light (from the Izh-2715.2 car); 6 - radiator trim (from VAZ-2107); 7 - headlight block (from VAZ-2106.2 pcs.); 8 - front bumper (of two from VAZ-2108); 9 - engine sump (StZ, sheet 81.5); 10 - rear cardan (from Moskvich-2141); 11 - front suspension (from VAZ-2121 Niva); 12-rear bumper (of two from VAZ-2108); 13 - rear mudguard (tires 83.2 pcs.); 14 - rear suspension (from VAZ-2121); 15 - rear axle (from VAZ-2121); 16 - rear wing (StZ cold-rolled, sheet 0,8,2 pcs. - mirror image); 17 - body (from a VAZ-2108 with an extended engine compartment); 18 - front fender (St3 cold-rolled, sheet 50.8. 2 pieces - mirror image); 19 - hood (from Moskvich-2141, modified)
