Hot answers tagged building
It would be difficult to get the exact rotations that you are talking about using Power Functions parts. The servo motor would be your best option, but its range is fixed to +/- 90 degrees from center. If you use a controller with variable speed, it will rotate through 7 steps to get to 90 degrees in either direction. If you're willing to look at ...
There are two sites I can think of that describe commonly used gear assemblies. Both sites make use of animations to illustrate how the gears work. LEGO Education: Constructopedia This web article produced by The LEGO Group introduces common, basic usages of gears and pulleys. It includes alterations to the direction of gears, idler gears, gearing up/down ...
I've had trouble finding good examples as well. One of the most interesting one is, sadly, in Spanish, but the images (and some help from Google Translate) helped me some. Hopefully it can be a start. http://www.hispalug.com/foro/index.php?topic=11730.0
If you don't need constant speed motion a better idea would be to use a crank running from any modern motor (ie, geared down internally). That way you can guarantee the end points. For a 240° rotation you might need to gear up after the crank, but as long as there's a spring or constant load in one direction backlash shouldn't be an issue. Here;s a really ...
Only top voted, non community-wiki answers of a minimum length are eligible