Montessori Style Permanence Box

This object permanence box is a simple but very exciting toy for toddlers. The ball is inserted through the opening on the top, disappears for a brief moment inside the box, and then rolls back out into the collection tray at the front.

The play principle playfully supports the understanding that objects continue to exist even when they are briefly out of sight. At the same time, it promotes hand-eye coordination, grasping, releasing, and repeated experimentation.

The model consists of a sturdy box, an integrated collection tray, and a separate lid. The lid is held by magnets and can therefore be easily removed. This simplifies cleaning the box and allows for quick removal of any stuck balls.

The balls have a diameter of 55 mm and weigh approximately 40 g. This weight has proven to be very suitable for me: the balls are heavy enough to roll smoothly through the box, but still easy for small hands to grasp.

Each ball consists of two hemispheres connected by a printed threaded piece. Optionally, the thread can be secured with a small drop of superglue. However, this is not absolutely necessary if the connection is clean and secure.

My grandson is 7 months old and already handles the toy very well. Nevertheless, of course: like all 3D-printed children's toys, this toy should only be used under supervision.

Printing and Assembly Instructions

PLA, PETG, or comparable materials are suitable for the box. After printing, all edges should be checked and lightly deburred if necessary, especially at the insertion opening, the outlet, and on the balls.

The lid is secured with magnets. Make sure to glue the magnets securely and check their polarity before gluing.

The balls are assembled from two hemispheres and a threaded piece. If desired, the connection can be additionally secured with a drop of superglue. Please use only a very small amount of glue so that nothing leaks out.

Safety Notice

Please check before each use that all parts are securely seated. Especially magnets, threaded pieces, and ball halves must be securely connected. The toy is intended for toddlers but should only be used under supervision.