I am 62 and love building gadgets and toys for my friends and family. I have made dozens of these for sale and to give as gifts.
I made this one out of walnut and use a wide mouth peanut jar. But they can be made of any sort of wood you have laying around. I can usually make 2 or 3 a day. I used a router and a home made jig to make the larger hole. But when the local boy scout troop came to my shop to work on their woodworking merit badge, I broke down and ordered a 3.5 inch Forstner bit to drill the holes. Their Moms loved them.
-Christian Jensen; Nephi, UT