I would like to invent a way for me to move large heavy objects (couch, pinball machine, furniture, etc.) up and down stairs in my house by myself without putting my health at risk. I'm looking for ideas. This does not need to be a fast method (could involve lengthy setup for each use). I just want to be able to do it by myself and to not damage the item being moved. My motivation is to save my back from injury and be independent from having to wait for a friend/family to help, but I only need to do this a few times per year. I am aware of solutions such as a hand dolly for stairs, or even motorized dollies but those are not necessarily big enough to move something like a large couch. And the motorized ones are way to expensive (and big to put in storage) for what I need this for.