Cracked Hinge on Mac Portable

JDW

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Is this portion of the chassis removable - a subframe?

Yes.

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TOP
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BOTTOM
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JDW

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is this a common problem? I’ve not heard of it before.
One other person in this thread has the same exact problem. And @techknight has a recent video (mentioned earlier in this thread) showing a Portable with the same cracked hinge holder too. That means there are likely others out there.

Sadly, many Portable owners seem to be hibernating, Stephen. For example, I have tried REALLY hard to get a peep out of the folks in the Mac Portable FaceBook group, but it's like pulling teeth.

Gone are the days of DanTheAppleMacMan on EBAY who often sold Portables. Those guys were really knowledgable and would provide quick answers and feedback, but I never owned a Portable back in those days.

Seems like most Portable Owners these days never use the machines and simply have them in a closet.

Well, I've been working on a video about my Mac Portable for more than a month now, and once that video goes out, I suspect there will be renewed interest. And when people see my crack (ha ha), some may chime in after checking out their own machines.

What I can tell you is that hinge takes a lot of pressure when you close the LCD. A lot! The crack closes when I fully open the LCD. But if I put my thumb and all my might on top of that cracked hinge, hoping to keep it pushed closed while I close the lid... well... that's utterly impossible. So yeah. The lid puts THAT much force on the hinge! It's pretty crazy Apple chose to make it out of something other than metal. Even Portables with that hinge holder intact are ticking time bombs, in my opinion.

Also, when I first got my portable, there were other tiny parts that had broken off that subframe. None were critical. They were just tiny tabs. I was able to get them back on with superglue and they continue to be attached today.

It's because there is so much stress on that HINGE HOLDER that I have taken huge pains and a lot of time trying to figure out how best to CHEMICALLY WELD it back together. But tiny air bubbles compromise the strength of the bond a bit. DCM is better than superglue, by far, but not as strong as the original unbroken part.
 

Stephen

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The broken hinge cannot be repaired with glue, it will continue to break. I suspect that the existing structure can be reinforced economically (such as metal 3D printing).

I’ve been very busy recently but the direction I would explore is a custom 3D printed reinforcement bracket which is screwed into the existing sub chassis. Mounting points should reflect the force direction so that the new holes reinforce the brittle plastic - not weaken it.

FDM may be impractical if there’s limited space available. The metal option is becoming very affordable and would be my first choice.

Maybe it’s time for an old dog to learn new tricks (3D Modeling)? @JDW
 

Paolo B

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The broken hinge cannot be repaired with glue, it will continue to break. I suspect that the existing structure can be reinforced economically (such as metal 3D printing).
Agree: without proper reinforcement it will never work for regular use. 3D printing something out of metal seems to be an interesting proposition, but I am afraid it would just offset the bonding issue somewhere else. Maybe waiting for a chassis to pop up on eBay is the most reasonable proposition, unfortunately many Portables are failing due to the LCD…
 

Stephen

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Agree: without proper reinforcement it will never work for regular use. 3D printing something out of metal seems to be an interesting proposition, but I am afraid it would just offset the bonding issue somewhere else. Maybe waiting for a chassis to pop up on eBay is the most reasonable proposition, unfortunately many Portables are failing due to the LCD…
I am envisioning a perfectly form fitting bracket which is both epoxied and bolted into place — ideally, this will spread the load over the entire upper chassis rather than just the upper segment of the hinge mounth.
 
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joevt

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There appears to be some voids on the underside of the subframe assembly (shown in this image on the left side) that could be filled in with putty to add reinforcement?

1764117867312-png.24936
 
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Stephen

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There appears to be some voids on the underside of the subframe assembly (shown in this image on the left side) that could be filled in with putty to add reinforcement?

1764117867312-png.24936
Definitely! This could be a great place to add more support for a bolted on reinforcement bracket - or just plain old reinforcement!

mod anyone tries it, I recommend a two part epoxy. I’m suspicious that this alone won’t eliminate the risk of cracking (could maybe even make it worse?) but it will definitely be stronger.