I marked the holes by putting a dowel center in the end of a long piece of 1" dowel. Run it through the holes in the base plate, and bang on its end with a mallet. Rotate it a bit and bang it again, and repeat. Odds are the dowel center won't be precisely in the center of the dowel, so you'll be making a small ring of marks. The center of the hole is, of course, the center of that ring.
Build your own platform bed frame at your home by following the source linked tutorial given above. The source link also includes more pictures that can help you to build a better bed frame. You can see a step by step set of instructions and guidelines to follow with real life pictures, as well as you can download a PDF file detailing the list of materials and tools you’ll need, know about the length of every board, and most importantly color-coded illustrations of the building process.
New information on composite materials, adhesives, and finishes brings this book into the 21st century, while more than 300 photographs bring important visual information to life. This edition covers the nature of wood and its properties, the basics of wood technology, and the woodworker’s raw materials. Understanding Wood was written for woodworkers by a scientist with a love of woodworking. It will be sought after by craftsmen and collectors alike.”
I used the factory edge of the half-panel of hardboard as a guide for cutting the ply. I wanted to cut a 5-1/2" strip, and my saw cuts 4-1/2" from the edge of the shoe, so I wanted the edge of the hardboard 10" from the edge of the ply. So I set my combination square to 10", and used it to mechanically set the distance. Hint - if you need two things to be precisely the same length, try to avoid measuring them separately. Use some mechanical mechanism for setting the distance.
Grizzly is a company currently undergoing an upheaval. This brand was once known as a manufacturer of professional grade tools and equipment for woodworking products. Though, in recent years, that reputation has begun to slip a bit since being bought by the Chinese company SIEG. These days, whether the Grizzly product stands up to its previous standards of excellence often has more to do with what you are buying than the company itself.