Lego vacuum cleaner powered engine; a LPE without pneumatics


Februari 20, 2006. This month, I found a special topic on on engines that work without pneumatics. The cylinders and air stream switches are realized with technic Lego.

This picture shows the engine. It can be powered by putting the mouth of a vacuum-cleaner-tube on top of the engine. The movie , starring Guusje with a vacuum cleaner, shows how it works. The next picture shows more details of the crank axes. There are two cylinders and two air stream switches. The switches are open at both sides (red) while the cylinders are closed as much as possible (semi-airtight).

The next picture shows that all cranks rotate with a phase shift of 90 degrees relative to each other (0, 90, 180 and 270) My son, Joep,17 years old, told me so and he was right :-( again..

Just for the explanation I have built a crosssection of a cylinder ( upper axis) with an air stream switch (lower axis). The inlet/outlet can be connected with a vacuum cleaner. I assume that the engin also works if it is connected to a blowing end of a vacuum cleaner.

The engine appears to be fast, but not very strong. So, I assume that a lot of improvements could be made.

A very nice and simple engine is presented in Dan's workshop. His double action twin cylinder is an engine that doesn't simulate a real engine. It works as a true LEGO engine because it takes full advantage of all possibilities with Lego brick material.

Januari 2007. On the LowLug forum in the section "Technisch" and the topic "Pneumatiche motoren" (in Dutch) a 3-cylinder design has been discussed. The inventor, Rene Kok, has shown that a third cylinder yields more advantages that one expects. Animations are presented by Mahjqa in this topic. Of course, I wanted to test this idea and I tried to built a modular 3-cylinder version of this engine. Phase shifts between two cylinders are now 60 degrees in stead of 90 degrees.

Unfortunately, I could not make this one work properly.