Question about Supports/reinforcements for a structurally sound bed frame
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Hi! For context Our plan is to work around an existing wooden bed frame (the frame lays flush to the mattress), and build a long U shaped box around the frame that covers about 3/4 of the mattress. The corners of the frame will be rounded by kerfing the wood. (Ignore the headboard in the photo we aren’t making that) The “box” needs to be strong enough for sitting on, getting in and out of bed aswell as my (very big) dog jumping up on.

So my question is, how many support beams/ legs /cleats would you recommend we add to make this secure and not split, bend or wobble, and what thickness/ type of wood would you recommend also? The “box” will be 50cm high, 15cm wide, and 570cm long (200cm each side of the bed, 170cm at the bottom)

Sorry for any inaccurate terminologies, my dad is going to be building this not me, but I wanted to get some tips from here! Thank you! (P.s our Version varies from the images a bit, so just use the photos as reference what I mean by “U shaped box”