4-1 Accessories: Spinner and Propeller

The spinner is shaped from the same round bar stock that was used for the core of the annular radiator. The photo shows the square wood block before it was turned into a round bar. Make sure the block’s ends are perfectly perpendicular, draw a center line, and carefully drill the rotation-axis holes from both ends using a pin vise. Then, turn the square block into a round rod and divide it into two pieces—one for the radiator and one for the spinner.

Fix the finished round bar to the handle of an old carving knife with instant adhesive. Using a small knife as if sharpening a pencil, carefully rough-shape it. Finally, hold the handle and rotate it while using a file and sandpaper to form the spinner into a streamlined bullet shape.

These are the finished spinner and its rotating shaft. At the left is the 1.0 mm-diameter brass wire shaft, with a very fine copper wire coiled like a spring around its end and soldered to prevent it from slipping out. Next to it is a brass tube, inner diameter 1.1 mm and outer diameter 1.3 mm, into which the shaft is inserted. The other end of the shaft fits into the spinner’s center hole; when the tube is held and the spinner is spun, it rotates freely. On the right is the sheath-like brass tube (inner diameter 1.4 mm) that will be mounted at the center of the annular radiator.

The propeller represents the Junkers VS111 type—characteristic of German aircraft—with broad wooden blades. First, shape a block according to the front view of the propeller. Prepare enough material for four blades (one serves as a spare), then cut them into individual pieces.

This shows the blades after the twisting process. Although material was prepared for four blades, all were successfully made, so one was not needed. The twist shaping requires delicate, precise work: carefully carve the rough shape with a small knife while observing reference photos, and then finish with sandpaper. It is a process that clearly benefits from the experience gained through repeated trial and error.

Here, the completed blades are test-fitted to the spinner, together with the previously made rotating shaft. When blowing gently on the blades while holding the outer tube of the shaft, they rotate smoothly—test passed.

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