 |
David Cook ROBOT ROOM™ |
|
| home | projects | contact | copyright & disclaimer | books | links | ||
LEGO MindStorms Crown Gears
Click on each gear above for a frontal close-up. You can even read the numbering.
During test trials, I was having problems with one of the wheels on my mini-Sumo robot. Both wheels are driven by motors mounted overhead with power transferred through a 90-degree turn via 24-tooth LEGO crown gears. Despite nudging and adjusting the position of the motors, one gear frequently clicked and slipped. Upon closer inspection, I discovered the gears were slightly different!
3650 (1977-1990) The left-most gear has the narrowest, most-pointy teeth.
3650a (1991-1994) The middle gear has the widest, flattest teeth.
3650b (1995-present) The right-most gear has sloping teeth and four additional spokes connecting to the hub.
Click on each gear below for a side close-up.
The right-most gear is the most modern design. Its sloped teeth are probably more efficient than the fuller, squared teeth of the middle gear. The sloped teeth are probably stronger, more angle tolerant, and less prone to slippage than the narrow, pointy teeth of the left-most gear. The extra spokes on the hub may improve flatness and rigidity.
If you happen to discover additional variants, won't you let me know?
Answers Provided By:
After first posting this page, I asked Dave Baum, author of Dave Baum's Definitive Guide to LEGO MindStorms to take a look at these gears. He knew the answers to my questions (now included in the main text above).