Ballista

This is a working model of a Roman Balista in miniature , its made from PLA and TPU/TPE , ideal for waging war in the living room !
It will require no additional non printed parts other than a drop of glue .
Four parts , the string , two torsion springs and the trigger spring need to be printed in either TPU or TPE , the rest is all PLA , i like to make the stock in Wood PLA as it looks nice .
The trigger pawl needs to be reset after the string is pulled back using the lever on the end of the trigger pawl axle , the axle for the trigger pawl is the only thing that needs a drop of glue once its pushed through the pawl just to lock the two pieces together but you may find its tight enough without .
I've included a lot of pictures to help describe how to build it otherwise just print one of everything except the limb and torsion spring that you need two of and the bolt (arrow) that you can print as many as you need.
The torsion spring has three settings , low , medium and high power