The path of Machines is all about complexity. The old definition of a machine may include levers, but the path of machines needs more complexity than that. The path of machines thrives best on computers, engines, speaker systems. One interesting effect of the path of machines is that by default, it works on computer data but not on the written word -- which means written secrets are safer.
Machines that are characters in and of themselves (like an AI) resist spells normally. An active caretaker can resist many effects with the appropriate repair or use skill. Signature gear always gets a save. But for the most part, machines don't get resistance rolls.
The effectsSense Machine: lesser sense machine can detect machines, identify a machine, or diagnose a technical problem. Greater sense machine can reveal a machine's purpose or get a password from a computer.
Strengthen Machine: Most commonly, this is used to increase the power of a machine, whether it be strengthening a car to get up a hill, increasing the CPU speed on a processor, making a speaker louder, or causing nanobots to act like there are twice as many of them. The difference between greater and lesser strengthen machine is one of magnitude.
Restore Machine: can perform complex repairs. Lesser effects require some nods to physically fixing the object and require all the parts and information to be present in some form. Greater effects can repair objects that are missing parts or have had the information on them completely destroyed, and do so instantly.
Control Machine: Lesser Control Machine makes the machine do something it could do with the right inputs. It can hijack the output of computers, speakers, and other media, (the resulting output has to come from somewhere though!), steer cars, and open locks. Greater Control Machine can allow a machine to move or act in ways it normally wouldn't be able to. Examples include a car walking on its wheels and a computer delivering an electric shock. Control Machine also works as Control Mind vs. AI's.
Destroy Machine: Lesser Destroy machine breaks machines in subtle and believable ways, causing fuel lines to come loose, random computer crashes, and other normal wear and tear (if faster and much more convenient). Greater Destroy machine can erase information from a computer so thoroughly it can't be gotten back or cause mechanical errors that require taking the machine completely apart before putting it back together.
Create Machine: Lesser create machine can grant a bonus to assembling or inventing a machine, or copy a machine's effects that the caster has all the information for. For example, lesser create machine could be combined with sense machine to open a lock. Greater create can awaken a computer to sentience, or assemble a machine on its own out of spare parts. It can also emulate a machine
Transform Machine: Transforms one machine into another, causing it to do something it was not designed to do. Lesser effects are subtle and still somewhat related to the machine's design, while greater effects can restructure the entire machine into something else.
In the CampaignThis path is very much designed for a high tech game, and isn't recommended for TL's less than 6. Though it could be used in a TL4 world to create clockwork constructs (effectively TL4+2^ or even higher!) It will shine best in world with lots of computers, vehicles, and machine-type weapons (like guns).
I hope you find this idea useful!