Peter Logan, 45, from Glasgow, committed the rapes over 18 years at addresses in Glasgow and Carnoustie.
He was found guilty of two rape charges, one of indecent assault and two of assault at the High Court in Glasgow.
Logan was finally brought to justice after the daughter told her mother that Logan had raped her when she was aged between 15 and 18.
The mother, who cannot be named for legal reasons, confronted Logan and both women went to the police.
Logan, whose science fiction novel Pen was published in 2015, claimed the women were liars and denied all the charges against him.
Defence counsel John Scullion said: "He was convicted of very serious offences.
"It is fair to say the jury also acquitted him of very significant aspects of the indictment.
"Given the nature of the convictions, the accused accepts your lordship must impose a significant sentence of imprisonment."
Judge Lord Kinclaven said: "As was rightly said there is no alternative to a significant custodial sentence."
A spokesman for children's charity NSPCC Scotland said: "Logan has been proven to be a sexual monster who inflicted pain, fear and misery on a mother and daughter over a prolonged period of time.
"The seriousness of his crimes is reflected in the lengthy prison sentence handed down and we now hope that his victims are given the help and support needed to recover from what has happened to them."
An author who raped a woman and her daughter has been jailed for 11 years.