QiYi WuJi 7x7 - how much force is safe to apply?

[AdamsImmersive]

I’ve never dissembled a cube above 3x3, but I’m considering replacing a slightly damaged corner on my new QiYi WuJi 7x7.

1. Is the right approach to remove a pair of adjacent edges next to it first—by turning those 2 layers to 45 degrees and... twisting/pulling the 2 edges together as one?

2. Will I need to remove any other parts as well to free up the corner piece?

3. Most importantly, how much force can a puzzle like this take during disassembly? Am I likely to break pieces accidentally and wish I’d never started?

Thanks in advance for any advice!

I’ve watched videos on similar cubes but they all seem MUCH looser than mine—pulling on those edges and/or pulling layers apart just feels like things are going to break! (And I know I can’t loosen the cube without disassembling anyway.)

 

[xyzzy]

And I know I can’t loosen the cube without disassembling anyway

You can. Just remove the centre caps and loosen the screws by about a full turn. You can tighten them back after assembly. Don't try to force pieces in when the cube is on tight tensions; when in doubt, just loosen first.

Also, it's easier to just pull out two adjacent edge pieces together without misaligning the layer first. From there you can remove the surrounding centre pieces, and then try to wiggle the corner piece out.

 

[Tabe]

To answer your question, the Wuji can't take that much force. The plastic on them is not high quality and they break easily.

I recommend taking the center cap off, scotch taping all the center pieces together, then loosening the center completely. Then take the entire 5x5 center off in one piece.

 

[AdamsImmersive]

You can. Just remove the centre caps and loosen the screws by about a full turn. You can tighten them back after assembly. Don't try to force pieces in when the cube is on tight tensions; when in doubt, just loosen first.

Interesting—many thanks! YouTube steered me wrong. I was indeed able to get the caps off using a tool I made out of an old credit card. Sounds like I’d better not attempt to disassemble at all without loosening the screws first.

(Although the screws won’t budge even with considerable force, so I think maybe I’d better back away and live with the minor corner damage rather than destroy a $45 cube. I feel like I’m likely to either break the center pivot or else strip the plastic inside where it joins the metal screw.)

Also, it's easier to just pull out two adjacent edge pieces together without misaligning the layer first. From there you can remove the surrounding centre pieces, and then try to wiggle the corner piece out.

I’ll keep that in mind. But how do you grab the two edges if you don’t turn their layers?

 

[AdamsImmersive]

I recommend taking the center cap off, scotch taping all the center pieces together, then loosening the center completely. Then take the entire 5x5 center off in one piece.

Helpful trick! I’m definitely thinking this cube is not user-serviceable without a lot of risk!

If I attempt that, I’ll count the screw turns to avoid over-tightening on re-assembly.