KORUZA v2 motor system
KORUZA wireless optical system operates by shining a collimated light of beam across a distance of up to 200m and is capable of throughputs of up to 10Gbps. The current 1.0 version is 3D printable and in all forms simple to modify for just about anyone with basic equipment. Our current development of the next generation system however is aimed at producing units at a volume and making them suitable for the telecommunications marked.
We’ve started with a development of mechanical modules. The new mechanical design needs to be production friendly and must enable low cost production. Material chosen for backbone structure of KORUZA v2 is aluminum because of its low mass and price, it is also easy to shape using various tools (CNC laser cutter, Waterjet, CNC milling and turning). Our first priority, speaking about mechanical module, was to reinvent motor system used for laser beam alignment, required to reliably direct all the light from one unit onto another. Inside KORUZA, motorized alignment is responsible for controlled movement of the lens tube joined with the enclosure with a pivotal joint. The motorized system moves one end of the tube in X-Y axis and thus creates an angular change in lens tube direction, aiming the optical beam. Complexity of this system is caused due to the non-linear spherical movement of the tip of lens tube, when system is moving on its x-y axis and simple mechanical joints can not be used. Since new Koruza will have much smaller outer dimensions it has to be more compact without compromising accuracy and reliability.
Because of the movement of the lens tube, we have to ensure movement of the end of the lens tube in all directions simultaneously. In the first iteration of the prototype we used the design with spherical bearings, which enables simultaneous movement in all three axes. We used the M5 metric thread, which was responsible for movement of the lens cylinder in x and y axes. In this design a motor and a nut are freely suspended with the use of spherical bearings. To eliminate movement of the motor and the nut in the axis of rotation (backlash) we would need to use a series of springs, which makes the system unreliable and complicated, that is why we abandoned this design.
In attempt to resolve the issue from the first design we replaced the spherical bearings with a flexible spring coupler at the motor side and with a plain radial bearing at the nut side. This design in theory allows movement only in x or y axes, while allowing the spherical travel of the lens cylinder. In the experiment we found out that this design is extremely sensitive to the concentricity of the motor axis with M5 rod and parallelism holes in the nut and coupler, resulting in non-linear movement of the IR beam.
Sliding linear nut system:
The design, which accommodates all our requirements, is a nut with a sliding surface that enables movement in linear direction and at the same time free spherical movements on the other nut. Plastic used for surface sliding nut has excellent self-lubricating properties, allowing smooth linear movement without sticking or shaking. The retraction force is reached with one diagonally positioned spring. Such system of movement is compact in size and enables easy installation. Moreover, indirect burden on the engine axis and lower operating torques will result in a longer engine life.