The problem

Hi there all (hopefully) helpfull people of the r/BdsmDIY community. I have the Auping Original which on their site they mention is steel (will be relevant later). I've been tying just using rope but its a bit of a hassle to find the right point to tie to and because the point that I tie to is usualy a beam underneath the bed I find that the rope can shift and slide, which makes that it is not very restrictive. I don't need the person to be tied so firmly implace that they can't move their arms/legs an centimeter (3/8") but now its just a bit to much (more like 10/20cm or 4/8").

A possible solution

I was thinking off adding rivnuts, either the countersunk (schematic) or the normal ones (schematic). Since it is a steel frame, I would probable get the stainless rivnuts and paint both the rivnuts and the frame after I drilled the holes to prevent them from being shiny and to prevent any chance of galvanic corosion (altho based on my research the chance is quite low if there is no water). Then comes the choice of where to put them, Id either want to put them on the top or on the bottom of the matrass frames (not on the bed frame since its rouned and it only covers the sides). As for the top vs bottom situation, the top would be easier to tie, but would need to be removed everytime after play and if I ever wanna sell the bed in the future it would be the most visible off both options. The rivnuts on the bottom would be less visible, could be kept installed, easier if I wanna sell the bed but harder to acces during play.

As for the actual points to tie to I was thinking about an eye bolt (version 1 or version 2) both stainless because I think its smoother and would let rope run along it better. But I might want to paint it black if I leave them attached in order to hide them better. An other option would be an eye bolt with ring. I love these because they have a wide opening (5cm/2" instead of the 1.5cm/1/2" of just the eye bolt). It would make it easier to feed rope or webbing through, it will also make more sound and im also scared that it will start to leave marks on the bedframe in the long run as the person in the restraints moves and the metal of the ring slides along the metal of the bedframe. Also they would probably be better accesable from above even if they were mounted on the bottom of the bedframe, but they would need to be removed because they are so large. (ps I might still wanna paint them black because it looks cool, but I'm not sure if paint and rope rubbing against it is such a good idea.)

Thank you

First of all thank you for taking the time to read my post, please let me know your thoughts and experiences they will be very help full and in the end that helps me make the best decision on how to move forward with this project.

Part 2

I might make a later post asking for advice on where to place these tie points around the bed in order to best restrain someone.