Metal contortionist. I need this no matter how unrealistic this is.

Reminds me a lot of the discipline suit story, only more extreme because of the contortion part.

I guess a plaster cast would be a lot cheaper, but there is no other escape route than a partner. So don't try that alone.

Ye. That and the long deploy time make it even more annoying unless you plan on doing some ridiculously long term bondage which is likely detrimental to health.

These really caught my attention.

Ye, The first one is similar and could likely be decently functional if you could get into it.
The second one is the most basic one but easiest to do as it is just a kigurumi style thing with a hard plastic one piece swimsuit with dildos impeded.
The third one is perplexing.
Never have I felt such a use for the ability to read Chinese as bondage art.

Did work on the idea and here is my proposal for the rotational locking joint that I think should be used in designing mannequin like suits. The design is actuated by embedded electromagnets on the internal plate of the joint while the gear contains magnets on the inside that allow it to slide in and out of its locking position. 

The parts required are limb covering hard plastic pieces with one internal plate and one external plate for connecting to the other plate. Electromagnet and wiring needs to be embedded on the internal side.
An axle that locks with the gears that has matching teeth on both ends and that curves in the middle to accommodate your joints.
2 gears with magnets embedded inside. The gears have teeth that narrow in width at the very end to assist sliding into place. They have teeth inside for the axle and outside for the outer plate.

The gears when locked lock one of the external plates and the one side of the axle down

To get out simply reverse the electromagnet and the gears should be pushed back out again

Should be self bondage compatible and fairly non disruptive. To make the suit wearable normally just use a circular piece that doesn't bind with the external plate.

Did work on the idea and here is my proposal for the rotational locking joint that I think should be used in designing mannequin like suits. The design is actuated by embedded electromagnets on the internal plate of the joint while the gear contains magnets on the inside that allow it to slide in and out of its locking position.

The parts required are limb covering hard plastic pieces with one internal plate and one external plate for connecting to the other plate. Electromagnet and wiring needs to be embedded on the internal side.
An axle that locks with the gears that has matching teeth on both ends and that curves in the middle to accommodate your joints.
2 gears with magnets embedded inside. The gears have teeth that narrow in width at the very end to assist sliding into place. They have teeth inside for the axle and outside for the outer plate.

The gears when locked lock one of the external plates and the one side of the axle down

To get out simply reverse the electromagnet and the gears should be pushed back out again

Should be self bondage compatible and fairly non disruptive. To make the suit wearable normally just use a circular piece that doesn't bind with the external plate.

I appreciate your effort but I don't really understand your idea.  I think I would need to see a 3d model to get it.  I am very intrigued, however.

Did work on the idea and here is my proposal for the rotational locking joint that I think should be used in designing mannequin like suits. The design is actuated by embedded electromagnets on the internal plate of the joint while the gear contains magnets on the inside that allow it to slide in and out of its locking position.

The parts required are limb covering hard plastic pieces with one internal plate and one external plate for connecting to the other plate. Electromagnet and wiring needs to be embedded on the internal side.
An axle that locks with the gears that has matching teeth on both ends and that curves in the middle to accommodate your joints.
2 gears with magnets embedded inside. The gears have teeth that narrow in width at the very end to assist sliding into place. They have teeth inside for the axle and outside for the outer plate.

The gears when locked lock one of the external plates and the one side of the axle down

To get out simply reverse the electromagnet and the gears should be pushed back out again

Should be self bondage compatible and fairly non disruptive. To make the suit wearable normally just use a circular piece that doesn't bind with the external plate.

I appreciate your effort but I don't really understand your idea.  I think I would need to see a 3d model to get it.  I am very intrigued, however.

Here you go. On one side the blue part rotates on the red part while on the other side the grey gear slides on the red part and locks when pulled into the blue part.

You can also shield one side of it if you can't bend the joint backwards like knees and shoulder for added security and reducing skin shown. Skin shown can be covered by a stretchy silicone layer to make the ultimate suit.

Still working on a locking hollow ball joint but that takes a bit of effort to design.

I claim my unholy victory over the problem of their being no locking ball joints that don't depend on friction. Behold! The interrupted screw ball joint.