Furniture leg extender

We wanted to increase the height of a shoe rack so that our robot could crawl under to clean. So I designed some leg extension. In this design, there is a hole that I manually threaded to fit the original screw of the leg that was in contact with the floor. If I want to make extra sure the screw is not going anywhere, I can insert an M5 nut in the slot. I did not need it though. I printed it with quite high infill (50%) to make sure it would hold the weight.