Do you have a dog? If yes do you think your dog has enough action during the day and enough outside time? even if you answer now with yes this toy is greate for him.
You can fill in dog food in pellet form which fits the hole in the role (diameter is 15mm). Your dog will smell the food in the role and you can show him a little bit (if he does not get it by him self) how to turn the role. By turning the role the pellets will drop out. This keeps the dog busy for some time and it is a good mind game for him.
Step 1: What You Need...
First this model is designed for 3D printer owners ;)
Means print the Edge pieces 6 in total 4 of Edge and 2 of Edge2. Also print the roll and role top part.
Also get yourself the rods according to the partlist. Diameter here should be 15mm or slighly small if you want to glue it together. Pipes will also work, but I do not recommend to print them since the dog will push a lot on them and depending on the dogs size the forces could be too much.
Step 2: Printing Tips
1. The models should be aligned optimal already for printing. If the are like on my screenshot printing without supports should be possible on nearly every printer.
2. Use a high enough fill in since the forces depending on the dog can be high.