One can do wonders with a pile of scrap metal and a little magic.
Clockwork Eidolon: A mechanist begins play with a powerful construct by his side called a Clockwork Eidolon. The eidolon forms a link with the mechanist and the two are connected by their very souls. An eidolon has the same alignment as the mechanist who built it and can speak all of his languages. Eidolons are treated as living constructs (such as warforged), not dying until reduced to a number of negative hit points equal to their constitution score.
A mechanist can infuse life in their eidolon in a ritual that takes 1 minute to perform, should it be destroyed. If constructed this way, it returns with half its total hit points. The eidolon does not heal naturally over time. Should the eidolon be destroyed, it cannot be reconstructed until the following day. If the mechanist is asleep, unconscious, or dead, his eidolon immediately ceases to function as its spark of life is directly tied to the mechanist. It revives when the mechanist regains consciousness.
The eidolon takes a form built by the mechanist. The eidolon’s Hit Dice, saving throws, skills, feats, and abilities are tied to the mechanist’s class level and increase as the mechanist gains levels. In addition, each eidolon receives a pool of evolution points, based on the mechanist’s class level, that can be used to give the eidolon different abilities and powers. Whenever the mechanist gains a level, he must decide how these points are spent, and they are set until he gains another level of mechanist.
The eidolon’s physical appearance is up to the mechanist, but it always appears as some form of mechanical creature. The eidolon also bears a glowing rune that is identical to a rune that appears on the mechanist’s forehead as long as the eidolon is summoned. While this rune can be hidden through mundane means, it cannot be concealed through magic that changes appearance, such as alter self or polymorph. This ability replaces Eidolon.
Clockwork Minions: Starting at 1st level, the mechanist gains control of a clockwork minion. This minion is identical, statistically, to an eidolon, except that it is small instead of medium in size. The mechanist can have a total number of minions equal to ½ his class level. The strength of the minions is based on the mechanist’s level, and they follow the eidolon’s progression table, just as the eidolon would.
However, if the mechanist has multiple minions, he must divide their strength by assigning “levels” to them. He has a number of “levels” to assign equal to his class level, and he must divide them amongst his minions. The minion is treated as an eidolon of a mechanist of a level equivalent to the number of “levels” assigned to it. (Example: Quates, a level 8 mechanist, has 8 “levels” to assign amongst his two minions, Blender and Slasher. He decides to assign 5 levels to Blender, and 3 to Slasher. This means that Blender is treated as an eidolon of a 5th level mechanist, and has 4 HD; and that Slasher is treated as an eidolon of a 3rd level mechanist, and has 3 HD.)
Each minion has its own individual base form and its own evolutions. This ability replaces the Summon Monster I-IX and Gate abilities.
Living Construct Clockwork Eidolons are living constructs and, thus, do possess a constitution score unlike other constructs. They have low-light vision and are immune to all poisons and non-magical diseases. In addition, they gain a +2 bonus against all mind-affecting spells and effects. Note that, as living constructs, clockworks are made of metal and, therefore, are subject to effects such as heat metal, chill metal, and rusting.
A clockwork eidolon cannot be healed by “cure” spells, but can be healed by both spells that specifically heal eidolons and spells that heal objects.
Limb (Treads): A clockwork eidolon with treads moves at a speed of 20 feet, but is more stable than if it were walking on legs, gaining a +4 bonus to its CMD against trip and bull-rush attempts. A clockwork eidolon with both treads and legs can switch freely between them as a free action. A clockwork eidolon can only have one set of treads. Only a clockwork eidolon can take this evolution.
Shrink: A clockwork eidolon can, as a standard action, shrink, making itself one size smaller. During this time, it cannot make any attacks and is treated as being flat-footed. It may take another standard action to return to its normal size and regain its faculties. Only a clockwork eidolon can take this evolution
Smuggler’s Hold: This evolution gives the clockwork eidolon a hold somewhere on its body, where one can place any items they might see fit to hide. On a small eidolon, this hold is 6”x6”x3”. On a medium eidolon, it is 1’x1’x6”. On a large eidolon it is 2’x2’x1’. And on a huge eidolon it is 4’x4’x2’. By spending 1 extra evolution point, the clockwork eidolon can ignore the weight of objects hidden inside the smuggler’s hold. Spotting a smuggler’s hold on a clockwork eidolon is a DC 20. Only a clockwork eidolon can take this evolution.
Limb (wheels): This evolution adds two wheels to a clockwork eidolon. A clockwork eidolon with wheels moves at a speed of 30 feet and, moving downhill, gains +10 feet to its land speed. Taking this evolution twice grants the eidolon a +4 bonus on its CMD against trip and bull-rush attempts. Only a clockwork eidolon can take this evolution.
Medium Size: This evolution increases the clockwork eidolon’s size from small to medium. It gains +2 strength, -2 dexterity, and is treated as a medium creature. Only a clockwork minion can take this evolution.
Magnetism: This evolution allows a clockwork eidolon to climb more easily on metallic surfaces. The eidolon can climb on metallic surfaces as if using the spider climb spell. Only a clockwork eidolon can take this evolution. The mechanist must be at least 5th level to select this evolution.
Combine: A clockwork minion with this evolution can combine with a mechanist’s Clockwork Eidolon, granting it an extra evolution. The clockwork minion must be at least one size smaller than the clockwork eidolon to use this ability. As a standard action, the clockwork minion combines with the eidolon, granting it access to one of the minion’s 1-point evolutions. The size of the evolution is equivalent to the eidolon’s size, not the minion’s size (example: a small minion combining with a medium eidolon, granting it claws, the claws would deal damage as a medium creature, not small). Any granted evolutions based on HD are based on the HD of the minion. If the eidolon does not have the prerequisite evolution to use a granted evolution, he cannot use it (example: a serpentine eidolon with no arms cannot use the claws evolution granted by a minion.) By spending 1 extra point, the minion can grant a 2-point evolution. By spending 2 extra points, it can grant a 3-point evolution. By spending 3 extra points, it can grant a 4-point evolution. By spending another extra point, the minion can grant one more 1-point evolution (this second evolution can be enhanced as well by spending the appropriate amount of evolution points). This evolution can only be applied to a clockwork minion. The mechanist must be at least 5th level to select this evolution.