Page 77 - Build Your Own Combat Robot
P. 77

Build Your Own Combat Robot
                  58
                        FIGURE  3-11
                          A passive wheel
                            arrangement



















                                      Getting the torque from the shaft to the wheel requires a high-strength hub con-
                                    nection. You should consider using the largest shaft diameter that you can locate
                                    and design into your robot. Not only will the larger shaft diameter withstand
                                    damage from hazards and weapons much better than a smaller shaft, you will find
                                    it easier to machine a slot, a “D” flat, pin holes, or key slots in the larger shaft (see
                                    Figure 3-13). With the larger shaft diameter, you will require larger pillow block
                                    bearings that will withstand much greater forces. So, larger is better in these cases
                                    for greater strength.


                        FIGURE  3-12
                           Placing a hub
                            directly on a
                         gearmotor shaft;
                         the hub can then
                        be directly attached
                             to a wheel.
                             (courtesy
                            of National
                           Power Chair)
   72   73   74   75   76   77   78   79   80   81   82