The joints are the weakest point of any skeleton. Any moving part, really. I can make the materials as hard as mandalorian iron or quantum crystalline, but if the joints aren't protected, the skeleton is compromised. Even then, the joints will remain a weak point of the whole. The goal is to make them as tough as possible, as maneuverable as possible, and as reliable as possible.
I think I've got it down this time.
Quadranium steel bones and joints are the key. I then reinforce the bones themselves with more quadranium and some titanium, then molecularly bond the two substances together for added strength. The joints are made primarily of quadranium steel, but with titanium added into the mix as well. These are molecularly bonded as well, but unlike the bones themselves that feature titanium rods bonded to the bones, the titanium here is... well, the best I can describe it is layered or maybe 'swirled' into the joints themselves.
Titanium coils are bonded into the quadranium joints in a coiled or looped manner, making the joint very hard to break or damage. It can be done, sure, but short of a direct hit from something like a Skocha, it should hold together. I have no idea what something like Force telekinesis would do, but I'm fairly certain even masters of the skill won't be pulling arms and legs off this armor without anything less than full concentration.
The best part is that while it renders the joints a little bulkier than I'd really like, but only a little, the skeleton is fully maneuverable. One of the testers I crammed in it complained of the weight (it's not powered yet, so I can understand that a heavily reinforced quadranium skeleton would be a bit weighty) but otherwise wasn't hindered in any way when moving around.
This is good. Very good. And just to cover my bases, I had the same tech shoot the skeleton with some Tenloss weapons. Disruptors tended to do the most damage, but didn't actually break anything in half. They mostly just pockmarked the bones and frame with some deep scars. Regular small arms didn't do much, blasters just scorched the metal. Even the RAB was used and it mainly did the same as the disruptor, albeit with less effect.
I stress tested the skeleton after the testing and found that while the damage done by the disruptor and RAB caused the armor to redline the stress levels on the limbs affected at certain times and levels, the overall loss of durability was maybe 30-40% effectiveness. Not great, but far more than I was hoping. The skeleton will do, I think.
The repairs were easy enough to do as well. Bones that weren't integrally compromised were touched up with a bit of molten quadranium where damage deformed a bit of metal or were left alone when the metal was only scuffed or scorched. Pockmarked bones that were heavily damaged were tested with the damage repaired and, when still not at 100% durability, were removed and replaced.
The benefits of replaceable parts, I guess.
So, now, I have a fully functioning quadranium skeleton with excellent durability and high damage resistance to build off of. With minimal scuffing and scorching, even.
Granted, I have no idea what lightsabers will do to this thing, but I think that's the least of my worries at this point.