A SCOOTER OR CITY BIKE? | MODEL CONSTRUCTION

Less and less will see on our roads a nimble scooter. This is not surprising: the main producers and their fates were abroad — in Latvia and Ukraine. So what else from this series is now sold in specialized stores, is cars. Accordingly, the price… To all that volatile MOTOmed gives the consumer a more convenient, more modern cars of the same class — scooters. Miniature scooters with 50-CC engine with automatic transmission and starter, can reach speed up to 80 km/h, providing comfort, who never dreamed of the owner of “Riga” or “Carpathian”.

But why spend money on trendy scooters, if it is possible to convert an old moped in a more modern car of a class “city-bike”? Machine, with the design which we want you to meet, is compact, reliability and increased comfort, justifying its belonging to the family urban mini-mokikov.

It should be noted that city-bike was created on the basis of mokiki “Karpaty” (in principle, come to any other or moped mokik engine sh-58, sh-62 or /-50). In particular, it was used front fork with steering column, rear pendulum suspension with shock absorbers, seat, engine /-50 and all sorts of things like lights, control handles and tail light. Wheel city-bike — mini-mokik Riga production.

City-bike was designed using flat models. To do this on cardboard in a convenient scale of 1:2 was drawn silhouettes of all the finished components and assemblies — the engine, front and rear forks, shock absorber, headlamp, etc. of Course, it took also articulated silhouette of the driver.

The development layout was started with placement on the plane of the drawing of the hinge silhouette of a man in a position comfortable for riding on mokiki. Further, under the “driver” was summed up seat and foot pegs, under his hands and arm. The position of the arms determined the coordinates of the front fork and, accordingly, the front wheel, then it was easy, given a wheelbase (in this case 1060 mm) to determine the coordinates of the center rear wheel, rear fork and shock absorber.

The next stage is the placement of the power unit and the fuel tank. The most rational position of the motor on the frame is where the center of the drive sprocket of the engine, the axis of the pendulous fork and axle rear wheels are on the same line — in this case, the swing rear fork swings the tension of the drive chain is minimal. Thus, the location of the engine on the frame has also been defined unambiguously. Yes and post on mokiki fuel tank capacity of about 5 l was easy: the only more or less suitable place for him — under the saddle of the driver.

Initial stage of layout of the city-bike with flat models.

Articulated silhouette of the driver (A) and its components (B)

The hinged silhouette of the driver (A) and its components (B).

The layout of the city bike:

1 — fairing; 2 — headlamp; 3 — wheel; 4—mirror; 5—frame; 6 — saddle driver; 7 — fuel tank; 8 — rear wheel; 9 —engine V-50; 10 — front wheel; 11 —footboard; 12 — brake pedal; 13 — handle throttle control of the carburettor (“gas”); 14 — brake lever; 15 — the lever of the clutch control.

Then followed what was required from the Builder of this development, the Union of all components and assemblies mokik tough, durable and lightweight frame. The easiest version of it — in the picture. This frame spinal type of steel square tube 34×34 mm and round with a diameter of 20 mm, with fixing points of the engine (front and rear) and mounting brackets shock absorbers.

Manufacturer of city bike began with the Assembly of the flat part of the frame consisting of the cap and the seat beams and the steering column. These elements were joined on particle Board, which was previously drawn frame city bike. Plaz be allowed to adjust elements of the frame and to control its geometry after welding.

The next step — manufacturing and securing by welding on the frame seat portion of a steel pipe with a diameter of 20 mm. Pipe bend according to the conventional technology: it is filled with dry sand, place the bend was heated with a blowtorch, after which the workpiece is twisted around a suitable mandrel (steel pipe) with a diameter of 130 mm.

From steel sheet of thickness 3 mm were cut out of the cheek knots of the engine mounts and brackets of shock absorbers. As can be seen from the drawing, the cheeks of the rear attachment engine embedded hinge of the pendulum fork and the sleeve for fixing the footrest city bike. And hinge, and sleeve represent the segments of pipe (bushing diameter 20×2 mm, hinge— 22×2 mm). After fixing on the frame of the rear cheeks of a node were installed the engine, and then adjusted in place and tack-welded the weld of the cheeks the front of the mount of the motor. Then the engine removed from the frame and cheeks are welded completely. Similarly welded to the seatpost of the frame and cheek arms are shock absorbers.

To check correct Assembly of the frame it was mounted front and rear wheels, then the frame is inverted and in this position, checked the parallelism of the wheels.

The steps of mokiki represent a steel rod with a diameter of 16 mm, recorded in the dedicated to the grommet with a pair of plug lap joint. Foot pegs stretched rubber covers from mokiki. With right side mounted brake pedal, bent steel rod with a diameter of 10 mm, which is welded to the steel sleeve. On this sleeve is fixed by welding the brake lever consists of two steel plates with a thickness of 2.5 mm, and the sleeve frame is welded a support under budenovskoy sheath of the brake cable.

Fuel tank city bike-suitable from cans of 5 liters. To secure the cans on the seat part of the frame provides the cradles of the steel strip 30×2 mm. cross section At the bottom of the canister standard motor tap with filter-sump. In the tube of the fuel tank drainage hole with a simple flap of thin sheet oil-resistant rubber, prevents leakage of fuel in case of accidental fall of mokiki.

SNT bike with V-twin engine 50.

Frame city bike Assembly with front and rear forks:

1 — front fork (mokiki “Carpathians); 2 — steering column (mokiki “Karpaty”); 3 — solitaire (steel sheet s2,5, 2); 4 — cheek front-mount engine (steel sheet s); 5 — spinal beam (steel pipe 34×34); 6 — part of the frame, seat post (steel pipe 20×2,5); 7 — beam seat post (steel pipe 34×34); 8 — cheek rear hub mounting engine (sheet s); 9 tuning fork a pendulum, back (from mokiki “Carpathians); 10 — cheek bracket left shock absorber (steel sheet s); 11 — absorber left; 12 — bushing mounts foot pegs (steel pipe 22×3); 13 — the case of the hinge of the pendulum fork (steel pipe 22×2); 14 — bushing (Teflon or textolite); 15 — kickstand (steel rod Ø16).

Sizes with an asterisk * are specified during Assembly.

The drive of the brake of a back sprocket:

1 — cover pedal (cut the rubber hose); 2 — pedal brake (steel rod Ø 10); 3 — biscuit brake cable; 4 — the lever of a brake (sheet steel s); 5 — emphasis (sheet s4); 6 — sheath of the brake cable, bozinovska; 7 — bushing, brake pedal (steel pipe 24×4); 8 — footrest (steel rod Ø 16); 9 — case step.

Handlebar city-bike — mini-mokik Riga production, however, is not so difficult to do it on their own from a steel tube with a diameter 22×1,5 mm. fixed in the Headlight is welded to the wheel bracket.

After mounting on suspension city bike seat, engine and exhaust, the car was adjusted and tested on the go.

The latter was made the lightweight fiberglass fairing that gives mokik the right to be called the city bike. The fairing was designed to veclachi of fiberglass on the boob, and it made him not quite the usual form.

The idiot was going from blocks of construction foam. That fairing turned out to be symmetrical, I used the following method of processing boob. First brought only his left side, proshpaklevat it with clay and took the idiot several templates (cardboard). In accordance with these templates processed right side boob. At the end of the work to the clay surface prijateli thin plastic film to ensure the removal of shell from boob after veclachi.

Before Villenoy with fiberglass removed the wax coating, which the fiberglass was soaked in gasoline, but you can anneal — uniformly stretching a strip of fiberglass over the heated hotplate.

As a binder for vyklicky used epoxy resin. To obtain a shell of required thickness needed to impose on the boob five layers of fiberglass.

After polymerization of the resin shell was removed from the boob, putty and visquile, and then covered with soil and autosmart. The finished fairing is secured on the frame city bike at four points: the top bridge of the front fork to the seat post of the frame and the rear mount of the engine with attached to it a threaded bushing.

I. KARAMYSHEV,

engineer

Recommend to read

THE PLANE AND GLIDER
Schematic model of the airframe and the aircraft, as you know, started flying much earlier than their full-size prototypes. Paving the real aircraft's path in the sky, they are now...
COUNTER WEDGE
Wooden dowel hammered into the wall hole for the fasteners, over time, dries out and keeps bad, especially heavy items, such as kitchen shelves. Insert the before driving a small wedge:...