Heart shaped gears of corpse! Dracubecca is covered in them from head to boot.
1. How far apart the gears are. If they are too close they will jam. If you keep trying and put too much pressure on gears that are too close together you might even damage the gears or as Robecca would have said, grind. Ouch! If the gears are too far from each other they won't touch and so won't spin at all.
2. The shape of the teeth. Gear teeth must match each other in size and shape. If you put a large toothed gear and a small toothed gear together they won't be able to mesh or turn and again might get damaged. Isn't it fangtastic that Draculaura knows all about teeth?
Here are some more freaky gears to check out - flowers and stars this time - maybe Venusobecca would like these?