The objective of the toy was to teach children ages 2-7 to learn how to count, add, and subtract by using the toy. Since the toy was directed towards an audience of young children, all of the edges were rounded so that the child could not harm themselves by interacting with the toy.
The toy was also modeled after an octopus in order to attract young children. Bright colors and various textures, the base and the tentacles, were added in order to appeal to them as well. The octopus in general is made so it looks like it is splashing around in the water when the tentacles are put up and down.
This was modeled entirely in PTC Creo Parametric.
Some of the difficulties when modeling the device were during the assembly of the parts. Each and every part had to fit properly in order to function correctly which was difficult since PTC Creo does not tell you when parts coincide with each other or give you an error when this occurs.
Other difficulties included the movement of datum planes in order to add features to each part of the toy. Since PTC Creo does not allow you to extrude on both sides of the plane at unequal length, I had to keep moving the datum planes in order to place certain features on the toys currently. More specifically, the suction cups were hard to place, as well as the eyes of the octopus.
The tolerances for the mouth and exit hole were chosen to be RC fits since a ball is supposed to rolling through those areas. An RC9 fit was chosen for that purpose. An RC9 fit was also used for the reset mechanism since the part should have enough clearance to move properly without any obstruction. Tolerances for the bolts holding the arms in place were chosen to be an RC1 fit since it needs enough movement in order for the arms to rotate without much effort, but not too much that the arms flop around.
The toy is made to work so that once all of the arms are placed upward a ball will be ejected from the back of the toy. The ball can then be placed back in the octopus’s mouth and the arms reset back to the down position. The arm is connected to a smaller arm that blocks the path the ball would take to exit the toy. The smaller arm contains a tab and a spring in order to push the tab down.
Once the tentacle is placed upright, the tab fits into the groove in the lock plate, and the smaller arm would move out of the balls exit path. After all the arms are upright, the path would no longer be blocked and the ball will roll out. Inside the mouth of the octopus is a small “tooth” that is connected to the lock plate. In order for the ball to go in, the tooth must be pushed down which in turn pushes down the lock plate and releases all the arms in order for it to return to the down position. The diameter of the octopus’s mouth was chosen based on the fact that large bouncy balls from vending machines can be used with this toy.
The ball is a reward for pushing all eight of the tentacles up which is how the child could learn to count up to eight. Addition and subtraction can also be used with this toy by either adding the number of tentacles that are up versus those that or down, or vice versa. Subtraction can also be used the same way. For example, six tentacles are up and two are down. Children can add or subtract these numbers.