Ultimate gearbox variable gearing

thingiverse

This gearbox is designed to be highly customizable, requiring some effort from you to achieve the desired transfer of motion with five gears and four different ratios. You will need to select which ratios you want and then create the gears based on your specific needs. I have included the following gear ratios: 1:1, 1:2, 1:2.5, 1:3, & 1:4. The gears are designed with a common axle-to-axle distance of 25mm, allowing them to be stacked together for efficient use. However, it's essential to note that the gears are not interchangeable, and each set consists of a large, small, and driver gear. The small and driver gears differ only in hole size, with the driver gear featuring a 2mm hole suitable for many DC motors. All the gears are built with a .1mm tolerance, minimizing whining when running. I have made improvements to this aspect and encourage you to experiment with expansion values if necessary. In Cura, I set these values to -.1mm for optimal results. To illustrate how to achieve specific gearing ratios, let's consider an example. If you want a 1:60 gearing ratio, break it down into its primary factors (2, 2, 3, and 5). Since we don't have a 5 gear directly available, split it into 2.5 gears instead. The resulting combination is 2, 2.5, 3, and 4, which will produce the desired 1:60 gearing ratio when multiplied together. This gearbox design allows for various ratios from 1:2 to 1:256, making it a versatile solution for your needs. Each of the five gears consists of the driver gear connected directly to the motor and four stacks of two gears (a large on bottom and a small on top). In Cura, you can place two models together and print them simultaneously by turning off Preferences -> General -> Automatically drop models to the build plate. This feature is essential for stacking the gears. Let's use our previous example to demonstrate how to create a 1:60 gearbox. First, select the 1:2 set and choose the driver gear from that set. The Driver 1:2 will fit directly on a motor. Next, place the Large 1:2 as the base for the first gear set, followed by the Small 1:2.5 on top. The second gear consists of a Large 1:2.5 and a Small 1:3, which are then followed by the Large 1:3 and the Small 1:4. Finally, place the Large 1:4 on top of the Shaft, which is connected to the reduced ratio. It's essential to note that this gearbox design requires bearings specifically (683zz or MR62zz), and these bearings are not interchangeable. You can purchase them from Amazon, with prices starting at $8 for a set of 20 or $13 for a set of 50. The files are named in a way that makes it easy to select and use the desired gears. For example, a large spoked 4:1 gearbox with a 7mm axle is named SpokedLarge1-4_7. This gearbox design is still a work in progress, but I hope this explanation helps you understand how to customize it to your needs.