Causes. In ALS, the nerve cells that control the movement of your muscles gradually die, so your muscles progressively weaken and begin to waste away. ALS is inherited in 5 to 10 percent of cases. The other cases appear to occur randomly.
1 The smaller studio uprights usually weigh between 400 and 600 pounds. 2  The monstrous full vertical or large upright piano can weigh as much as half a ton.  A studio piano's center of gravity is also lower than a large upright's, as it is about 4 feet (1.2 m) tall as opposed to a large upright's roughly 5-foot height.
Googling on spinet piano weight I found this answer (http://www.concertpitchpiano.com/WhyNotToMoveaPiano.html) to your last question and an object lesson as to why you shouldn't do it yourself. The average spinet or console weighs in at from three hundred to five hundred pounds. [snip] A young woman asked her father to help her move a piano from one place to another in her house. Her father got a couple of his friends to come along and they brought a dolly.