I have found this resource to be especially useful as I prepare to use the rekenrek with my students. In addition, I wanted to share with you the directions for making rekenreks for your students in my most recent math tool FREEBIE listing on Teachers Pay Teachers. I have included directions for making a wooden rekenrek (using a wooden door hanger) and a cardboard version.
So enlist the help of your husband, one of your kids, or a friend, and you will have some whipped up in no time. Good luck!