This is a Piercing Cradle for a 210mm (short side of a piece of A4 paper). It is used for properly aligning paper to pierce through it with an awl to make signatures (A5 sized) for sewing together when bookbinding. 

They are quite expensive to buy and as I was just starting to book bind I designed and printed my own and used bolts and threaded inserts that I had to hand.

I have included the .stl files as well as .gcode for 2 different configurations. You can make it with the end brace which will help you square your signatures before piercing. You should print:

• x2 Braces
• x1 End Brace
• x2 Boards

If you do not want the end brace then you should just print 3 braces.

In all variations you will require:

• x12 M5 buttonhead 16mm bolts.
• x12 M5 threaded inserts. (Insert using a soldering Iron)