I am going to make s step up box. Found numerous build spec online. For the ones that have built them, any tips/ideas that you would change in retrospect?
I recently made a 20" box from leftover materials to practice for Train to Hunt. It's nothing fancy, but it's functional and plenty strong. The top is two layers of 7/16" OSB sheathing (leftover from roofing a tool shed) cut into 24" squares. Legs, angle bracing, and X-bracing are all 2x4 stud scraps. It's held together with 2" drywall screws.
If I hadn't had enough scrap material on hand to cobble something together, I probably would've built a 5-sided all-plywood box. I like that particular design because you can get 3 different heights out of one box and turn the open side up to serve as a storage bin when not in use.
I recently made boxes for kids that I train. 6 sides, 3 different height options. Be sure to round the all corners and put a finish on it, so you don’t get your shins jacked up from rough plywood.
Agreed with making the six-sided box that allows for three different heights. Depending on the workout, you'll probably want some variety there (step-ups w/ pack or weights vs box jumps). Also definitely sand the corners unless you really like that hairless/skinless shin look.
Use 3/4 plywood and braces. Multiple sides are best. For step ups you don’t want to over extend so having a 20” side is good and for doing box jumps the 24” side is good for that movement. Wear shin guards, lol.