*** PART OF MY INDUSTRIAL GEARBOX COLLECTION ***
This is a fully 3D printable version of an industrial spur gearbox / gear reducer. This cutaway version can be used for training purposes, and has a gear ratio of 1:3.5
A spur gearbox is arguably the simplest and most common type of gearbox. It uses gears of different sizes. For example, if the first gear has 5 teeth and the second gear has 20 teeth the ratio is 1:4. This means that if you turn the first gear 720 degrees the second gear rotates 180 degrees.
No additional hardware needed!
*** UPDATE 7-16-2018***
I`ve added a cap that can make the gearbox non-cutaway, see the green parts in the fourth picture. When you want the gearbox to be non-cutaway, you have to print the file named with NON-CUTAWAY.