Probably a self bondage story that I can not remember how long ago I read.
As I remember it she crafted this device that she could install herself into, but there was a timer that made the device permanent by pulling pins out of each piece by means of a cable/winch setup.
From memory the device had boots, chastity belt, chastity bra and a head piece all made from metal.
There were wrist cuffs that hooked together and were then hooked to the back of her chastity bra in a reverse prayer configuration.
The boots were attached to a rocking spreader bar setup that raised a dildo that when fully raised locked into her chastity belt.
And there was something about a penis gag that gravity lowered into her mouth/head harness that also locked in place when fully inserted.
Once everything was permanently locked her computer sent an email to an old boyfriend that instructed him where to find her and how to remove her from the device while all the restraints were still in place on her.
Should be Fine Art by Knotty Master: https://www.selfbound.net/storiesek/fine_art.html
Thank you that is exactly the story I was looking for.