Our first Stirling motor which can use the lost heat from a cup of coffee as a drive. We at Böhm Stirling Technik are constantly striving to expand our product range to include new innovative and attractive Stirling motor models. With our new HB6 Stirling coffee motor, we have for the first time added a Stirling motor to our versatile product line which can make use of even relatively weak heat sources as a drive. It can, for example, be operated with the lost heat from a human hand or a hot cup of coffee. Stirling motors of this type, which can started up by temperature differences of less than 20°C and less, were realized for the first time by in the 1980s by Professor I. Kolin from the University of Zagreb and Professor J. Senft from the University of Wisconsin. Based on this pioneering work, we have used the concept of the two researchers for the construction of our new HB6 Stirling coffee motor. Thus, this model demonstrates impressively how thermal energy in the form of a weak source of heat can be transformed into kinetic energy. The operation of such a Stirling motor is relatively simple. When the cover plate is cold and the base plate warm, the air flows downward past the displacing piston and warms up there when the piston moves upwards. If the displacing piston moves downwards, the air then flows upwards and is cooled by the cover plate. As the operating volume is sealed off from its surroundings, this periodic temperature fluctuation results in pressure variation. This acts as a force on the working pistons on the cover plate. This force is then transmitted to the flywheel through the crankshaft and connecting rod. This converts the upward and downward movement of the working cylinder into rotary motion of the flywheel. The driving power for the displacing piston is taken from the flywheel, moved through the crankshaft and then transmitted to a second connected rod offset by 90 degrees. Our new HB6 Stirling coffee motor also gets its operating energy from the heat flow between the cover and base plate. To create this flow, the temperature difference between the plates must be sufficiently large. This can occur either by heating or cooling the base plate. To heat it up, warmth from a hot cup of coffee, a hand, a receiver, a computer monitor or other household appliances can be used. The motor can also be operated by cooling the base plate, which can be done by placing it on a bowl of ice cubes. In addition, it can also be used as a solar motor. The motor also operates if its dark top surface is heated by solar radiation and its base plate is therefore cooler than the cover plate. When operated with ice or solar power, the flywheel moves in the opposite direction, however, and the Stirling motor runs backwards. After the Stirling motor has been on source of heat or cold for one to two minutes, it can be started by gently cranking the flywheel in the correct direction. From that point on, the HB6 operates independently as long as desired. It is therefore an absolute hit not only for collectors, but also for lovers of technology!