CNC Top Cover & 4kg Hinge Installed

I just received and installed the new top cover & 4kg hinges on my 11th gen framework. I was tired of the wobble/flex/movement while the display was open past 150°.

my impressions:

  • the new top cover is 19g heavier than the old one. i would say the extra rigidity comes from the edges. the old cover had plastic channels where the magnets were attached to; instead the new cover has those features milled.
  • my new hinge feels considerably stiffer. the wobble/resonance is muted, but still present.
  • i haven’t used the laptop enough to make many judgments, but the new top cover feels much nicer (or premium as they’ve described). i’m less apprehensive about picking up the laptop along the top cover edges, as opposed to handling it from the base.

my analysis:

Regarding the hinges & wobble, however, I think we’re stuck that flaw for the current laptop form factor. @nrp posted an explainer, but this part stood out to me:

which essentially describes the hinge acting like a flat spring. I believe this is due to the hinge design because the distance from the hinge to screw holes is long enough to allow the steel to deflect and become springy. Of all the laptops I’ve disassembled, I can’t recall a one that’s quite this long.

The attached image shows Framework’s hinge design, compared to a 2015 13" Macbook Pro and a 7th (or 8th gen) Thinkpad X1.

  • The distance from the hinge axis to the center of the screw hole is about 18mm. On the Macbook, its less than 7mm to the closest set of screw holes.
  • The screen side of the hinge appears to be one piece of stamped steel (a), but the opposite side is a MIM produced part (b) riveted twice to a piece of stamped steel (c). The latter stamped piece is why it’s “springy” and flexes right at the edge (see 2nd attached photo).
  • If I had to “fix” this, I would change the stamping for part c. It would be wider along the riveted edge, and then folded over along the side perpendicular to the hinge axis. There appears to be enough free space for the left hinge, but the right hinge is very close to the power button.

But all of this might be completely wrong, or something that Framework already knows. I’m just another rando on the internet, after all…


Also notice that on the ThinkPad X1 hinge, there’s a 90 degrees bend creating a stiffer vertical plane.

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