I have a setup where I have a step motor which I am attaching a gear onto. The motor will make the gear stand horizontal in a small vehicle. Is there any good gear combinations of LEGO gears that can transform the horizontal torque of the gear into vertical torque that drives the wheels of the small car I am building?
Are there multiple combinations of LEGO gears that can provide this kind of torque transmission?
There are a number of ways to do this. Here is one of the easiest and earliest methods:
For that design, you'll need this part (3650):
And one of the 8-tooth gear variants:
You'll also need suitable Technic axles, Technic bricks (3700 is used above), and Technic plates (32001 in the example) to match your overall design needs.
You can also do something similar using a combination of bevel gears or double bevel gears:
I'd like to cover two other techniques that work well, they both transmit horizontal torque to vertical but in slightly different ways that I believe may be useful for different situations.
Worm gears are fairly small (less than two studs long). Worm gears are designed to be operated in one direction and can only be driven by the axle with the worm gear. You can get some very high gear ratios when combining a worm gear with another gear.
Knob wheels are only compatible with other knob wheels, they cannot be used with gears. They can be used parallel (like standard gears) and at 90 degree angles (like crown/bevel gears).
I find knob gears are easier and more comfortable to turn by hand and they appear to be more commonly included with recent Technic sets.
