got tired of trying to verbally describe it so i caved and made a messy picture
this diagram isn’t universal, as individual internal anatomy can vary wildly by frame and function and look nothing like what’s pictured
the spark is, obviously, the power center of the frame, and the core of personhood. it’s what distinguishes a person from a drone, and creates connections between people that determine who their family is. it hovers somewhere on the threshold of quasi-real, as a spark is half-submerged in subspace within its chamber, otherwise the sheer heat and power of this magical miniature star would very quickly lead to an explosion. it technically generates power all on its own without adding fuel to burn, but trying to power a frame without energon makes the spark gutter out. the spark charges energon, which then circulates through the frame and brings that life energy to every area, not unlike blood and oxygen. in stasis lock, when the frame needs very little power beyond basic self repair, their fueling requirements go way down since the spark doesn’t have to work as hard
the spark chamber is there both to keep the spark safe from the outside world, and to keep the outside world safe from the spark. if a chamber loses integrity, the spark will very likely burst. however, the chamber itself can be moved a little bit, lifting up and out so the connected T-cog and engine can be inspected. every spark chamber has four hardlines and ports, spooled away for interfacing directly with the nervous circuitry of the frame. it also holds innermost, a bright blue slurry of sentio metallico and highly charged energon that the frame draws upon for self repair. usually the innermost sits in its own section of the spark chamber, but it will regularly cycle into the same space as the spark to pick up charge again, and can be consciously pooled there as well
the engine is what makes the frame go. it works on translating the spark’s power into actual inertia, regulating momentum and pressure output, and even burning extra fuel to add a power boost when necessary. while the central mass is connected to the spark chamber and T-cog, the engine has a network of motivators throughout the frame
the T-cog is the central hub that controls transformation. it’s not so much a singular cog that turns as it is a whole collection of functions controlling dozens of individual parts of the frame, how they fit together, what mode they’re in, and how they switch between modes without intersecting one another, essentially the seat of power for one’s alt mode. it’s connected to the morph core in the processor, which flips between what kind of sensory input and proprioception the frame uses depending on which mode it’s in. some T-cogs have a mutation which support a triple-changer frame, and some have a similar mutation which create Mutacons, but the average mech has one root mode and one alt mode
the spark chamber, engine, and T-cog are always closely connected, as it could be said they are really all one single formation. an engine cannot move the frame without a T-cog guiding it, a T-cog cannot turn without a spark powering it, and a spark cannot burn without an engine supporting it. the most common placement of these three organs is in the chest, but some have them lower down, or even in the pelvic area. it’s fairly common for onyxoid frames to have them between the lower two shoulders, like with Sky Lynx here
the processor is the central computing hub of the frame, where the personhood of the spark gains expression with logic, emotion, and responsiveness. while the main mass is always centered in the helm of one’s root mode, there are multiple vitally important clusters of nervous circuitry throughout the frame that could be called mini-processors. beastformers especially often have a secondary computing hub for sensory input in their beast mode’s head, but it isn’t exactly comparable with the central processor
Rossum’s Trinity is a rather philosophical way of categorizing anatomy, calling the spark, the T-cog, and the processor the most important parts of the frame, given how damage or infection of one will inevitably lead to the decline of the other two. some argue that it is instead a ranking, with the spark as the highest and the T-cog as the least. some say that the trinity should be the spark, the T-cog, and the engine, or even the processor, the spark, and the engine instead. while it’s a fun thing to debate about, Rossum’s Trinity is not effectively useful in medical mechanics and largely left to conversation instead of practice
the forges are where eaten material goes to be digested, taken up by the self repair systems, and distributed to the frame for upkeep and repairs. the placement, size, and number of someone’s internal forges can vary wildly, and the diagram here is just as likely to be wrong as it is to be right. often times they’re somewhere near the engine so they can act as heat sinks, drawing away heat from the engine to repurpose for forging. since they’re made of metal, mecha don’t burn through physical material as quickly as humans do and don’t usually need a lot of food to keep their self repair systems happy, so their internal forges aren’t as large as you might expect
the fuel tanks are where energon is stored and circulated, as well as other non-energon fuels to be burned by the engine when needed. they vary in placement, size, and number even more than internal forges do. for instance, many flight frames have tanks in their wings! they have powerful pumps attached that help drive the circulation of the entire frame, no matter where in the frame they are. they’re also carefully partitioned with emergency shutoff valves that will slam shut if something punctures the tank, so that the entire thing won’t drain all at once
lastly, the protoform is all the underworkings and internals of the frame. struts, circuitry, wiring and tubing, mounts, joints, and beams, all carefully woven together. it’s usually modular, able to be sectioned off into limbs or vehicle parts or what have you. the protoform is covered by armor plating, and some of that plating forms functional kibble, pieces that perform one specific job, often only in alt mode, and thus have very little protoform connected to them. for example, in most cases a flier’s wings are not kibble, as they’re important limbs that often have vital anatomy inside them, but the horns of a beastformer are kibble, especially if they’re tacked onto the frame in root mode somewhere instead of being integrated into it. armor and kibble can be removed for a time without any harm coming to them, and some places are actually designed to retract or move aside, but protoform cannot be removed. armor and protoform are usually layered thickest over the spark chamber, but mecha can choose to retract them to show the chamber, for access to the spark, hardlines, and other internals
snowghoul
romaincrisis
stormborns
