THREE BLADE ON PILOTAGEWhat are the only propellers is not built by modelers. Due attention was paid to the three blade. Why not try to install them on a modern cord “acrobat”? If Yes, will any benefit from the extra blades? Elaborate design, drew and made templates. Finally cleaned the sawdust out of the room evaporated the smell of varnish. The case for breakdown in air.

The first minute on track was a pleasant surprise to start the engine with that screw quite easily. And in flight? Every athlete-proteinic will appreciate the result, which gave the use a three-blade propeller: it seemed (although in reality it really only seemed) that subsided to a strong gusty wind. The model is not dispersed in the figures, smoothly tracing and drawing the whole system. Another surprise, and also a nice improved manoeuvrability.
Happy (feelings rarely accompanies training in such weather) “atletas”, waiting to stall the engine to put pilotasso. Twenty seconds, forty… This has not been the engine with the old tank worked for 7.5 minutes instead of 6.51.
Now that the new propeller has passed multiple tests, I think the benefits of the “extra” blade fully cover the complexity of its manufacture. And, as you will see from the description, this complexity was apparent from the lack of experience of similar work.
Fig. 1. Basic dimensions of the blade.
Fig. 1. Basic dimensions of the blade.
Fig. 2. Pattern trimming the butt.
Fig. 2. Pattern trimming the butt.
But it is so. Start with a template from sheet metal (plastic for the shipment of screws does not fit). On them mark out and saw out three blades made of beech. Birch is easier to handle, but, unfortunately, heavier. And the flying km the moment of inertia of this “flywheel-gyro” it is desirable to have as small as possible.
Prepare another template, trim the butt of the blades are finished with it filing wood.
Assemble the propeller in two ways. They’re both very practical — has never been not only breakage of the blade, to n there was not a single crack at the butt end of the screw.
So the first way: propili mill the grooves for the washer from industrial, pasted with veneer of aluminum with a thickness of 1.5 mm on the resin K-153 glue all the parts screw into one. Then both sides glue it in the butt 1-mm plywood and drill three holes Ø 1,5 mm, into which insert pins (OVS Ø 1,5 mm). The second method is almost the same only a Central goal in this embodiment is made of parklea two layers of 1 mm plywood lining on the butt end of the screw thickness — 2 mm.
Ready carefully balance the propeller depends on not only the safe operation of any screw, but the mode of operation of the motor.
Fig. 3. Assembly of the propeller.
Fig. 3. Assembly of the propeller.
Fig. 4. The inspection device.
Fig. 4. The inspection device.
Still need to check whether all the blades in one plane. It can be done on mounted on plate detachable sock Carter, in which the left crankshaft support washer.
Finally, I would like to say that those who are lazy to cut new blades, can use a two-bladed wooden propellers. Three such obtained two new three-blade, and quite good.
V. SALANECK, master of sports of the USSR

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