THE FARM WILL FIT: THE WINDMILL SCARECROW

Themed collections about simple but efficient home appliances, without which no cost, private courtyard, “modelist-Konstruktor” published a lot (see for example, № 7’92, 5’95, 6’97, 6’99). However, interest in such developments is unabated to the present time, as evidenced by the editorial mail. Their technical devices designed for the use of scrap materials and home technology available to any novice, brings to the readers Solonin — the inventor and innovator, one of the active authors of our journal.

While in the garden something grows, people no rest from Raven, trying pulling off the seedlings. A lot of troubles and sparrows. Bumping in packs, they are able to devastate, for example, planting sunflower, not at all afraid nor scarecrows-scarecrows or fences from fluttering in the wind light objects. Won’t pass these winged rogues and before “the worst in the world bringing” — multfilmov Carlson, announced he really is. There is not whirring propeller, and a turbine are needed!

And indeed: the large blades of unusual shape, slowly (preferably uneven) pivoted in a horizontal plane by the wind, the birds make the same think about the self-preservation instinct.

The real analogue of this bird on the scarecrows can be considered as a device for measuring wind speed — anemometer, which previously, I remember, even the school was equipped with a meteorological. Despite the plainness of its design it has sufficient high autonomy and reliability in all conditions. The rotary mechanism of the anemometer is driven in the interaction of the wind and Cup of the blades, the shape of which one side is convex — shape and, on the other concave, zabegaeva creates resistance to the air flow.

Home workshop — not a factory for the production of meteorological instruments; and financial capabilities of most Amateur designers are not so large so as not to worry about the maximum simplification and cheapening of handmade wares. Therefore when making dynamic bogey appropriate wind Cup blades to replace the upper parts of thin-walled plastic bottles of soft drinks, and as the hub and center bearing to accommodate the bottle more whole and thick-walled (preferably Teflon or polyethylene, so that the friction losses in such an important site was minimal).

Much depends on the spokes of the wind wheel. They should be dostatochnymi, durable, light, also from available for self-telsikom material. This is consistent with the requirements of the plaster shingles (better — sawn). Extra elasticity such spokes, and a uniform distribution of the mechanical and dynamic loads that can give basic stretching — tight nylon or Mylar threads.

A few observations and tips for assembling dynamic bogey rotary type. Blanks (neck of the plastic bottles) are placed on the future of the spokes, which in the absence of plaster shingles can even serve 800-mm segments smooth branches. To avoid cracking, chipping and other complications when performing this, simple, surgery helps diametrical slot in advance done the walls of the notched blades.

Each of the spokes passing through impaled on her blade-“glass”, one end 10-15 mm protrudes from the imaginary rim of the wind wheel. The other ends of the spokes are inserted through the “chord” of the hole of the bottle is the hub and pop out (again 10-15 mm) from the opposite side. The walls here are more durable than the blade of”ryu-IOC”. And all because of a bottle — thickened (for example, from the bleach “Oksana” or “White”). She holds four cantilevered spokes, which are strung one blade-“glass” or even several pairs.

The holes for the spokes done in the hub so that the load is evenly distributed. However, they almost do not reduce the strength of the plastic walls, thereby eliminating the occurrence of cracks and breaks due to the pressure of cantilevered blades. A tight fit and elasticity of the material provide a durable and reliable fastening of the parts in all the nodes of the wind wheel.

Intermittently rotating Scarecrow prop:

1 —the blade-“glass”; 2— the back of the wind wheel; 3 — rotation axis (the steel pin), 4 — stretching 5 — bottle-hub; 6 — loop suspension (aluminum wire)

Extra-long hub:

1,5 — bottles; 2 — M4 screw; 3 — tube bottles; 4 — thrust washer (coin)

Strap-needles do not pass through the axis of symmetry of the sleeve, because it is released to a steel pin on which rotates the windmill. The pin passes through a hole in the bottom of the bottle and, following right on its axis of symmetry and never touching the spokes, rounded end rests in the inner tube.

Despite the fact that the wind wheel is installed quickly, easily rotates and, if necessary, removed freely, it safe from accidental jump-out the entire device with a pin. Resting in the side surface of the last edges of the bottom openings, a bottle-hub counteracts the overturning moment in the vertical plane. The frictional forces additionally occurring at the same time, inhibit the rotation of the wind wheel. And they are the greater, the thicker the pin.

Friction can be reduced, balancing design — placing its center of gravity on the axis of symmetry of the bottle-the hub by moving the lo-mouths-“glasses” on the spokes. Control a visual on the location of the pin relative to the edges of the hole with slow rotation of the wind wheel by inertia. If the point of contact of these surfaces is fickle and changes all the time, the balancing was a success.

To increase the strength of the structure can be applied to stretching of wire, thin rope, twine, Mylar tape, harsh thread, tape, or strong enough cord. Streamers tied to the neck of the bottle and to the spokes (for example, before the blades-“glasses”). The intensity of rotation of the wind wheel can be improved by increasing the number of neck parts of the bottles, in pairs worn by the opposite spokes. And it is valid when the additional blades located on the other side of the spokes. But in any case, it is necessary to design the wind wheel was balanced.

Increase the effect of bird scaring can be achieved by elongation of the mutually opposite blades. A needle should be cut in two. Received a narrow 800-mm strips with pointed ends need to fit into the holes of the blades-“glasses” and bind them in convenient places, and stretching to hang the flags, cut from the same plastic bottles and gives the the wind wheel additional, frightening birds properties of high visibility flashing and intermittent buzzing.

Bird-scaring the checkboxes don’t accelerate and brake the rotation of the wind wheel. So, we need compensation in the form of additional lopac-TEI-“glasses”. However, and here the optimum, as to a continuously rotating wheel birds will quickly get used to it. But if it is, while some time motionless, suddenly begins to rotate in the wind…

And again. Above the vineyard is the windmill should be placed only when the berries ripen. At other times it is unacceptable because it will scare away the bees, which pollinate the flowers and birds that destroy harmful insects and caterpillars.

As the removable axle of the dynamic of the Scarecrow, the steel pin is attached to the lower arches of the vine that its rounded end can be easily put on the windmill. The speed and convenience of performing this operation increases the loop of aluminum wire, fastened to the neck of the bottle-the hub and rod with a hook on the end for donning and doffing of the wind wheel.

To scare away the birds on the big garden steel pin hammer directly into the ground and put on it the windmill larger sizes. Long spokes made from short strips (plaster shingles), cementing them together with wire and soaked the joints with glue.

Increasing the length of the spokes leads to an increase in the load on the stretch. So they are not torn, make a number of adjustments. In particular, extend the hub podtykova another bottle and transferring to it (closer to the bottom) the common place of attachment of stretch marks.

The second ends of the stretch mark evenly distribute the load over the surface of the spokes. The longer the spokes, the greater must be the stretch marks.

Number of blades-“glasses” also depends on spoke length and is determined experimentally. Below the rounded head of a steel pin into the inner tube under the action of enhanced load, instead of PTFE, a metal disc (a coin), tightly inserted into the tube.

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