Hi Dennis,

I did manage to pull the brakes apart yesterday and took some pictures. I left the attached pictures in high resolution so that you can see the detail.

As you can see there's risen areas on both sides of the rotors with the outer side of the rotors having more deposits. Both rotors have this hard blackish material stuck to them which i presume is melted brake pad material. You can also see that the brake pads are grooved and not smooth. I presume the reason the pads are grooved is due to the hardened material on the rotors slicing through the brake pads. Thus wearing them through extraordinarily fast right down to the rivets.

I think the reason that there's more deposits on the outer side of the rotor has to do with the design. As you can see on one of the pictures, there's a brake pad that is riveted to a fixed mounting plate attached at the leg (centered on the axle) with 4 bolts. This part is actually warped (picture shows a bit of this) and the outer edge (radially) of this brake pad is worn more than the inner (due to the part flexing when braking). I'm not sure why the design calls for a brake pad riveted to a fixed part of the main gear. In my opinion, the cylinder assembly should be the fixed part with the brake pads free to extend and contract on the rotor as needed (to allow for pad wear). With the current design, the outer pad has to contract on the rotor more (more pressure) to make up for what the inner cannot (since it's attached to the leg and can only flex). Anyway, i guess my point is that having brake pads not squared on the rotor as they wear could also contribute to hot spots on the rotors/pads making them more conducive to twisting and melting.

Anyway, from what I see they overheated and gave way.

The rotors should be thicker (for mass) and larger diameter so that they can absorb more heat without reaching melting temperatures. Furthermore, the pads should be wider for said larger diameter rotor. Perhaps some cooling ducts through the wheel pants to the rotor aren't a bad idea either. I would also change the design to prevent the whole assembly from twisting and wearing the pads unevenly. This plane needs beefier brakes in a nutshell.

Please let me know if you have more questions.

Roger
N522RJ