190 grams. That's the Ferrum 50 with the full printed kit installed. Cage. TPU dampers. Antenna mounts. Camera shroud. The whole protective shell.

Compare with the iFlight Nazgul Mark 5 - around 210g for the bare frame, no real protective cage. Compare with the Rotor Riot Tank - 270g+ class, the original "heavy is good" build. Ferrum lands lighter than both, with more integrated protection than either.

Strip a "lightweight" frame like the Apex 5 down to 145g, then bolt on the prints needed to survive a real crash - cage, standoffs, camera guard - and you'll land heavier than Ferrum, with less protection per gram.

This frame is engineered as a complete system. Carbon, prints, and hardware are weighed together. Not separately to fake a marketing number.

True X is symmetric. Squashed X is purposeful. A wider front-back than left-right shifts the moment of inertia where the pilot actually needs it.

You get a frame that snaps through pitch flips with no drag, but resists unwanted yaw drift mid-roll. Camera footage stays planted. Power loops come out cleaner. Rolls don't wash out.

And props can't touch each other no matter how aggressive the rates. The geometry is the safety margin.

Stiffness scales by thickness cubed. A 7mm arm is not 16% stiffer than a 6mm arm. It's roughly 60% stiffer in bending. That math doesn't lie.

Stiffer arms mean motors stay perpendicular to the airframe under load. No flex = no thrust loss = no prop wash. You feel it on punch-outs and on hard yaw spins.

Stiffer arms also survive crashes that would crack a thinner arm. The Ferrum 50 isn't a "replace arms every other pack" frame. Build it once. Fly it for a season.

The arm lock is gigantic. A mechanical interlock between arm and body that dwarfs anything on a typical race frame. More contact surface. Less point loading. Zero rotational play under hard yaw or torque spikes.

On top of that we add a center screw that bolts the key lock straight through to the middle plate. The arm-plate sandwich becomes one monolithic structure. No micro-creep. No progressive loosening after 50 packs. The bolt-up holds the geometry the carbon was cut for.

Thicker carbon = stiffer body. Combine 7mm arms with the oversized arm lock and a screwed-down key, and the chassis stops behaving like separate plates. It behaves like a single block. That's where the gyro-clean flight feel comes from - the frame doesn't twist under load, so the motors stay aligned and the FC reads true.

Carbon transmits vibration like a tuning fork. Bolt the arm lock straight against the body and every prop imbalance, every bent shaft, every rough bearing fires into the FC stack as gyro noise. That noise is what causes jello, twitchy PID response, and motor heat.

The exact dampening stack: 5mm carbon arm lock + 1mm TPU on one side + 1mm TPU on the other side. The whole arm lock is sandwiched between two elastomer layers. All four arms share this one decoupling stack at the center - not four separate dampers. High-frequency vibration gets absorbed in the TPU before it reaches the stack. Mid-frequency vibration is shifted out of the gyro's danger band.

Optional upgrade: add an extra 0.5mm TPU shim if you want zero play. The factory sandwich already has ultra-low play - barely measurable - but the extra 0.5mm kills it completely for pilots who want a fully locked feel without losing damping.

This works with the arm lock and center screw, not against. The bolted joint stays mechanically rigid for thrust and torque. The TPU sandwich only damps vibration, not motion. You get rigid geometry and silent gyro at the same time.

Result: lower RPM filter cutoffs in Betaflight, sharper PID response, less filtering lag. Motors run cooler. Video looks cleaner. The tune you set is the tune you actually fly.

Light frames get pushed around. Wind, prop wash, throttle bumps - a 100g frame reacts to every disturbance. Authority feels twitchy. Camera shake creeps in. Cinematic shots look unstable.

A heavier frame has more momentum at speed. Once it's moving, it stays moving. The 1960KV motors and Gemfan 51466 props produce enough thrust to push 190g hard, but the mass carries that energy through corners and dives like a freight train.

Drop the same setup into a 130g frame and it'll feel snappy in calm air and unstable in real conditions. Drop it into the Ferrum 50 and it tracks. Heavy is a feature when it's matched to the right propulsion.