Replacing upper part of O48/50 skeleton

I'm trying to replace the chest/neck part of my AZO2's internal skeleton after finally getting the replacement part due to a heavy shoulder crack, and I'm having trouble separating that part from the part below it (the belly/torso section). It.... isn't coming apart, and I don't want to force it if I'm missing something obvious.

Just to double-check, you just pry it apart by hand, right?

Heat it up first! (where the parts come together) Best with a hair drier. Gently twist from side to side, carefully, helped with mine. Gentle force. Important is to work straight, no bending,or it might break off. 

(... you did take the arms and the bust part off, yes?

Yes, I did take those off at first, though I came across a guide that K2 made that recommended keeping both on, surmising that the grippy vinyl material would provide more leverage to get it off. What ended up happening is that it ended up detaching the whole spine from the hip. 🙃

Maybe it's a tolerance problem. I've never had this issue before.

You just pry it apart - sometimes a little vacuum seal forms between the chest piece and the spine, so it's a little more difficult to pull off sometimes. It IS just a vacuum though, so careful twisting and a good steady pressure will break the seal and let it come off eventually.

If it's easier to remove the spine from the hips, I'd say you should pull the whole thing out, hold the spine tight and pull off the chest frame piece, and then put the spine back in the hips. Much easier than trying to keep a hold of the spine while there's vinyl in the way.

I'll re-attempt this tonight.

On a related note, I noticed in a FS listing the existence of an aluminum sheath set to reinforce the shoulder joints. Is there something similar for Obitsu? 

http://us.sk-coolcat.com/front/bin/ptdetail.phtml?Part=dp-01b

Edited January 1, 2022 by chef_mai

I've actually tried using this exact sheath set (the small version, anyways) on my Obitsu 50s, and the aluminum itself is quite thick -  the screw holding the shoulder joint to the chest had to be loosened to give it enough space to slide into. It does kinda fit if you do that, but the problem is that it's meant to fit on a purely cylinder-shaped socket for the arm peg, and the current 1/4 Obitsu arm socket isn't quite the right shape...though if you happen to get a 60cm Obitsu body, it's perfect! 😂 As it is, it can provide some light reinforcement, but won't prevent damage from occurring.

You might be able to get a ring that works better for this if you find a piece of aluminum tubing that's the right size and cut it to fit, but as far as I'm aware, premade sheaths don't exist for Obitsus yet.

2 hours ago, chef_mai said:

On a related note, I noticed in a FS listing the existence of an aluminum sheath set to reinforce the shoulder joints.

Those were designed to fix a structural flaw in the DDIII body frame. The frame had a tendency to crack right at the joints those pieces protect. The drawback to them was that they kept the arms/legs from being fully inserted.

I finally was able to perform the swap. I had to pull the spine + chest skeleton apart from the hips, then I carefully twisted the two apart, which was a bit tricky since the spine itself is designed to be flexible. With some elbow grease + latching on to the top "vertebra", twisting was able to break the seal and get it apart. Putting it together also required twisting (vs. the hip re-insertion which was doable just with vertical force).