A Pillory quit study and hard to escape when the pin is locked.
I created different sizes with the following measurements for the Hands are 
* Hands: 47mm x 57mm -  66mm x 76mm
* Hands: 52mm x 62mm -  71mm x 81mm
* Hands: 57mm x 67mm -  76mm x 86mm
* Hands: 62mm x 72mm -  81mm x 91mm

Other Sizes can be created so just ask in the comments

Assembly

You'll need (Or something Similar)
1 Safety Pin – 8 mm x 28 mm - https://www.amazon.de/dp/B09B1Y8L86
4x M5 x 16 mm Furniture Screws - https://www.amazon.de/dp/B0DNDNKT31

Put the Screws in the smaller holes and tighten them 
* The holes for connection are a bit longer then 16mm which means it will press them together.
* While the holes in the Joints are a bit shorter than 16mm which means they won't block the Joint.

To lock put the pin in the holes in the middle.

To be honest I'm not so happy with this one I think it is to short but to change this I need to redesign my modle with more Parts to assemble…
But since I'm currently short on time this will take some time. So pleas tell me if you have any suggestions.