Here is one idea https://www.hometalk.com/34362627/diy-pallet-frame-bed
Hi! maybe this will help
Hello. Have you considered purchasing one of the steel bed frames as an alternative? It may be more cost-effective building one when you take into your time trouble and cost of materials and fasteners.
I recently purchased a frame for storage need and getting the 14 inches of storage below the bed. I’m very happy with this bedframe.