You would have to trust your carpentry skills.
1st you need 7 squares of hard wood, 100cmX100cmX2cm
I dont know how big you want your box but I'm gonna say 1meter to make the maths easy.
so you get your base, use corner braces to attach 2sides (corners) in 2places.
you should have now used 6 barckets.
now you need to take 2more squares and cut out 1x2cm slots in each square so that they will slot together to make an "X"
you dont need brackets for these but you do need to use brackest to fit them in to your box cornner.
now put 2more sides on the box.
finished.
You cant put a lid on it because you'd have no way to fix it. you should have ended up with a sorage box with 4 sections. the "X" will be pertruding by 2cm, you can cut this off before you start.
you do need a jigsaw, if youve not used one, then you need someone that knows how to use one well.
Its prob a lot cheaper and easier to buy step arobic platforms.
