With forced air

With the help of articles in the magazine «Modelist-Konstruktor», I built myself a universal power tiller based on a Minsk motorcycle. It turned out to be a good, hard-working mechanical helper. Its basis, of course, is the standard motorcycle frame, shortened (as recommended by the magazine) and fitted with the power unit and a two-stage chain drive to the rear axle (from an S3A motorized tricycle). The handlebar is home-made, as is the bodywork. And the fuel tank that fit perfectly into the design came from a Verkhovina-3 moped.

At first I used the power tiller, coupled to a cargo trailer, purely as a means of transport, and its performance caused no complaints. However, when ploughing heavy soils it turned out that the engine was in dire need of forced cooling.

After weighing my more than modest possibilities, I decided to remedy the situation by installing under the hood a small but sufficiently powerful fan capable of creating the required airflow for more intensive cooling of the engine than before. I quickly found a suitable three-blade impeller and an electric motor rated for 12 V DC. From materials at hand I also made an appropriate bracket and fixed it in a convenient place. But where could I get a DC source to make this “composite” fan rotate? Buy an expensive battery just for this?

Then it dawned on me: why not use the existing AC generator and additionally connect to it a rectifier bridge built on semiconductor diodes? The solution is very simple, but what would the result be?..

The result exceeded all my expectations. The forced-air cooling system assembled according to the simplest circuit started working—and so well that it is a pleasure to look at it!

«Modelist-Konstruktor» No. 5’98, A. KUSHER, Zhmerynka, Vinnytsia region.