Leonardo's crossbow

One version, a self-spanning infantry weapon called the Rapid Fire Crossbow (Balestra Veloce in Italian), is found on sheets 143r, 153r, and 155r.

[2] The other is the Giant Crossbow (Balestra Gigante in Italian) design intended to be a mounted siege weapon found on sheet 149a in the Codex.

Given the constant warfare in the Italian peninsula at the time, he wanted to expand and advance both his military and the territory he governed in the Milan region.

Leonardo responded by writing Sforza a letter that included a number of innovative machine designs with one of them being the Giant Crossbow.

At the same time, the interconnected levers then push the sliding plank forward until the drawstring is caught by the rolling nut, which is held secure by the sear's spring tension.

Such a design removed the need for external spanning tools that an arbalist had to carry and simplified the arming process of the crossbow.

The Giant Crossbow supports this theory in that the intended enormous size of the weapon was meant to invoke fear and panic in its enemies to keep them away, but it would still have the capability to cause great damage and injury had it been actually constructed and used.

[11] After a prototype of the Rapid Fire Crossbow built in 2013, the first working model was released on 24 June 2015 during a demonstration[12] at the Castello Sforzesco in Milan.