HDX Metal Shelving Connector

Do you like HDX metal shelving, but they don't make them tall enough? I had two sets of HDX shelves from Home Depot. The dimensions of the shelves are 37 in. H x 36 in. W x 14 in. D. I'm guessing the shelves are only sold with a maximum of 37 inch height for stability/safety/legal reasons--smaller footprint + greater height = less stable.

I really wanted to stack these shelves, but I couldn't find any "official" way to stack them safely. The bottom of the posts have welded, threaded holes for the plastic feet. The top of the posts have a removable plastic cap, but the inside of the post is not threaded.

So, I created my own part--the HDX Metal Shelving Connector. You simply remove the feet from one set of shelves and screw in the part. On the other set of shelves, you remove the plastic caps. The bottom of the part then is inserted into the top of the post.

Keep in mind that these shelves were not designed to be this tall. Please use extra caution if you decide to use this. Use them at your own risk. I will not be responsible for any harm that may occur if your shelves tip over. You should consider using a wall anchor to avoid tipping.

This part is designed specifically for the HDX shelves from Home Depot: https://www.homedepot.com/p/HDX-37-in-H-x-36-in-W-x-14-in-D-3-Shelf-Wire-Unit-in-Chrome-EH-WSHDI-006/204603431

Please note that the pictures of the actual part show the bottom of the rack where the feet usually screw in. Once you screw in the connectors into the bottom of the posts for the top shelving, you flip it over and then can place it on top of the other rack.

I'm sure this design could be modified to support other shelves from other manufacturers.

This Thing was modeled in Fusion 360 in 3 sections: base, spacer, and screw. See below for steps.