A Northumberland made a guillotine in his bedroom, which he used to cut off his own head, an inquest heard.
Builder Boyd Taylor spent several weeks constructing the complex device at the home he shared with his father in the village of Milbourn, near Morpeth.
The 36-year-old's father Robert discovered his son's body in January after hearing a noise which he thought was a falling chimney.
The inquest, at Wansbeck General Hospital, recorded a verdict of suicide on Thursday.
The hearing was told the complicated mechanism was primed to switch itself on at 0330 GMT and cause a blade to fall on Mr Taylor's neck.
In a written statement read out by South East Northumberland coroner Eric Armstrong, Robert Taylor said he knew his son had been working on something in his bedroom for several weeks.
He said he was woken by a "rumbling" noise which he thought the chimney had fallen off his roof.
The father and son worked together in the family building company, but Boyd Taylor had been off over Christmas, saying he wanted to stay at home.
Mr Armstrong said the guillotine had taken some considerable time to complete, which led him to be sure that a verdict of suicide was appropriate, although the
dead man had not left a note.
He said Mr Taylor's death was not a "spur of the moment" decision.
As he gave his verdict the coroner expressed sympathy to Mr Taylor's family.
After the hearing Mr Armstrong described the case as "horrific."
He said he did not know why Mr Taylor decided to kill himself but said that his father blamed the breakdown of his own marriage to Boyd's mother about 20
Mr Armstrong said: "This was not a complicated cry for help, this had taken a lengthy amount of time.
"It was a thought out plan to end his life."