Main sheets of wood: 18 x 450 x 280mm
Distance apart on ground: 300mm
Height from ground: 280mm
Thickness of planks: 35mm
I can’t jump up onto this one yet but it’s a really good size for jumping onto from curbs and so on. I’ve had no problems with it folding together or anything. Just make sure that it’s long enough. You probably want it to be at least 450mm long unless you’re practising precision hopping and things like that. I’ve attached mine with thin rope at the bottom. This holds my weight (about 60kg) fine.
Sandwich boards are lots of fun. I’m planning to build some progressively higher ones once I can hop up onto this one. Please tell us how your sandwich board turns out.
The string in that photo isn’t the thin rope I was talking about and isn’t strong enough. The rope I use is more like about a 5mm diameter when it’s not stretched.
I don’t know much at all about types of wood but I think it just has to be strong enough to hold the screws in place. I suppose it’d have to be pretty compacted or something like that.