GRP UPThe industry has already mastered the production of some basic parts from thermoplastics. This is an interesting and promising method for production of large series, however, for individual products it is of little use — complex technological equipment. But similar results can be achieved by using has long been utilized by modelers epoxy resin in combination with glass and carbon fibre.

For example, the manufacture of the split housing of the gearbox tail rotor of a model helicopter you can get acquainted with the basic techniques of working with fiberglass, with technological equipment. It should be noted that the hull is molded in this way, he worked on models for two seasons and no hassle in the process of operation.
Stipulate at the outset that without a lathe fixture for molding the body difficult.
In accordance with the drawing of the hull it is necessary to develop sketches of models of external and internal contours of the parts. When selecting materials for the model, note that the punch is desirable to carve metal, but for matrices you can use any material, including wood. Procurement models should consist of two halves and hold them together it is necessary so that after final processing, they are easily separated. Metal halves are glued together with epoxy resin, wood and plastic — nitrocream through the paper gasket.
All surfaces of revolution are processed on a lathe, with the utmost attention must be paid to the alignment of the workpieces relative to the parting line, the accuracy of the sizes of the nests under the bearings and the corresponding diameter of the centering rods on the punch and the matrix.
If the details are projections, tides, and other similar items, then the corresponding models are cut out separately and glued to the punch. In conclusion, the surface is carefully polished until glossy. It remains to divide the model at the parting line and you can begin to work on the matrix.
Fig. 1. Detail of housing produced by molding of an epoxy resin
Fig. 1. Detail of the regulator body obtained by molding of epoxy resin:
1 — pinch metal ring, 2, 3 — right and left halves of the body, 4 — the tides under the fixing screws 5 — screws.

Fig. 2. Design mold
Fig. 2. Design mold:
1 — punch, 2 — base of the punch, 3 — detent, 4 — matrix, 5 — barrier strip, 6 — wypracowanie screw, 7 — box matrix.

The basis of the last sheet is a sheet of Plexiglas with a minimum thickness of 10 mm. On it are mounted the latches, and then a few drops of model glue is attached to the base. The model surface is covered with parquet mastic type “edelvays” and after its drying, is polished to a Shine. To the base of the dock wall of glass — it can be done with vinyl electrical tape or plasticine.
Begin pouring the model epoxy compound. To do this, prepare the epoxy and add filler, gypsum, cement, aluminum powder or even fine dry sand (30-50% of the volume resin). Composition to fill those holes while its level does not rise CA 10-15 mm above the most protruding part of the model. After curing of the resin base is separated from the model matrix.
The time has come to separate the model and the base and the centering socket of the matrix to insert the punch. Brushing the lower part of glue, place onto the matrix base, and holding the resulting “sandwich” in a vise, give it few hours to dry.
Fig. 3. The mold (punch and matrix) for molding the housing halves of the gearbox
Fig. 3. The mold (punch and matrix) for molding the housing halves of the gearbox:
1 — the base of the punch, 2 — centering rods, 3 — clamps, 4 — matrix.

Molds are ready now you can start forming housing halves of the gearbox. As a binder it is best to take the plasticized resin, filler, glass or carbon fiber.
The order of veclachi. The matrix is filled with resin and filler. Then you set the base and the mold is clamped by a clamp to squeeze the excess binder. After curing of the composite mold can be separated and extracted from it the finished half. As well formed and the other half part. Depending on the configuration of the housing halves are held together with screws or rings.

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