Mix and match hinges to get the right force

I used the Framework Laptop with the default 3,3 kg hinges for some time. I enjoy that the Laptop can be easily opened with one hand. However carrying the Laptop while open would cause the lid to adjust the angle depending on the movements.
To resolve that problem I bought the stronger 4 kg hinge kit.
After mounting both it was still possible to open the laptop with one hand to around 90°. But any further adjustments would cause the bottom part to lift up. Thereby needing the second hand.
In order to gain back the ability to adjust the screen angle using just one hand, I tried mixing a 4,0 kg and a 3,3 kg hinge. I installed a 4 kg hinge on the left side, and a 3,3 kg hinge on the right side (power button). I now have found a pleasing middle ground.
The screen is stiffer than before, but still at all angles one-hand-adjustable.


Does this not cause any issues?

I’m not an mechanical engineer, but an electrical engineer. So take my guesses with a grain of salt.
You didn’t mention which issues you think of.
The involved parts are the lid which is connected via the hinges to the bottom cover.
The job of the hinges is to impede the movement of the lid relative the bottom cover at all angles.
When applying force to the lid and the bottom cover, the hinges should be weak enough, that they will rotate before either of them break. I trust Framework on that one. The weaker the hinges, the lighter the force acting on the lid has to be, before it moves. To reduce movement, Framework introduced stronger hinges, increasing the force threshold.
Changing the angle by grabbing the lid at the center, should result in equal forces at each side of the lid, given the hinges are of the same kind.
Having different hinges, should put more force on one side of the lid where the stronger hinge is, resulting in stress that deforms the lid elastically/plastically. But then again the difference between the forces is only around 20 % (4/3,3)

Changing the angle by grabbing the lid at the side where to weak hinge is installed should apply the most stress to the lid. While grabbing at the side where stronger hinge is installed should actually result in less stress on the lid, compared to two strong hinges.

Grabbing at the center I notice no deforming at all.
Grabbing at the weak (in my case the right) side results in some elastic lid bending. But then again the Framework Laptop lid was never rigid.
By comparison, grabbing at the strong side (in my case the left) reduces the elastic lid bending.
I change angles mostly by using my left hand, so I intentionally put the stronger hinge on that side.

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