Basic ballistae are made of wood and held together with iron plates around the frames and iron nails in the stand. The main stand has a slider on the top, into which are loaded the bolts or stone shot. Attached to this, at the back, is a pair of 'winches' and a 'claw', used to ratchet the bowstring back to the armed firing position.
The slider passed through the field frames of the weapon, in which are located the torsion springs (rope made of animal sinew), which are twisted around the bow arms, which in turn, are attached to the bowstring.
Drawing the bowstring back with the winches twist the already taut springs, storing the energy to fire the projectiles. The bronze or iron caps, which secured the torsion-bundles are adjustable by means of pins and peripheral holes, which allow the weapon to be tuned for symmetrical power and for changing weather conditions.
The ballista is a highly accurate weapon for a primitive weapon.
Metals and Alloys
https://netheril.net/forums/index.php?topic=943.msg5845#msg5845The most you can learn about Golems here, other than their basic functions and types is that one must obtain ether a premade golem and bend it to your will or find a copy of 'The Manual of Golems' to create one.