A Solarium for Cucumbers

The development of agriculture depends not only on the work of professionals, but also on the initiative of those who from childhood are fond of technology and experiments. Schoolchildren can also contribute to this cause: growing new crops on training plots, designing agricultural tools, and creating compact mechanized devices that make work on the land easier.

Young technicians often propose simple and original solutions that can quite well be implemented in an ordinary school club. For example, members of the vehicle design club at the I. K. Krupskaya Palace of Pioneers and Schoolchildren developed a cold frame that stands out for its simple design and the availability of materials. Other beginning designers will also be able to reproduce it.

We asked Konstantin Ivanovich Kruglikov, the head of the vehicle design club, to tell us how this cold frame is built and how to make it with your own hands.

The design of the cold frame is, on the whole, traditional — it is a box with a vaulted roof of polyethylene film. The material of the box sides is wood or, as in our case, slate; it is more durable. The slate sheets are joined to one another with aluminum angles and cadmium-plated M5 bolts.

Supports are screwed to the side boards at one-meter intervals, and the vault arches are fitted onto them. They are made from aluminum gymnastic hoops Ø 900 mm. The latter are sawn through and, using a template, bent out to Ø 1200 mm.

The halves of each newly obtained circle are used for the arches, and the cut-off and straightened ends are used for the supports. They are joined to one another by steel rods pressed into the supports.

The end arches are also fastened with screws at the center to uprights, which in turn are screwed to the sides of the box. These uprights play an important role in the cold frame design. The point is that, besides the arches, they also carry the half-frames and the locking battens.

There are half-frames on both sides of the cold frame, and they are intended for ventilating it. They are raised like suitcase lids and locked in the chosen position with battens, or thrown over to one side, which makes it possible to open the cold frame completely.

The half-frames are made of wooden rails and beads nailed together with small nails, with the polyethylene film of the vault clamped between them. The rails are attached to the end uprights hingedly: with hinges and M5 bolts.

Wire rings are set into the side beads, and elastic cords are tied to them parallel to the vault arches. They keep the polyethylene film taut when the cold frame is fully closed. This prevents the film from flapping under sharp gusts of wind and, as a result, from being damaged.

When the cold frame is open, the film is gathered by special catches attached to the side rails on the inner side of the half-frames — the collectors.

In the closed position the half-frames fit tightly against the edging, which is also made of wooden rails and fastened to the sides with metal plates and bolts.

The cold frame is set on a garden bed and sunk a little into the soil. To avoid premature damage to the structural elements, they are first painted with oil paint. At the end of the gardening season the cold frame is taken apart and stored in a utility room until the following spring.

«M-K» 8’84