Acer C731 issue with broken hinges, Poor design

Shedcomputerfixer

I've recently been give 33 Chromebooks to fix for a school. Six were not Acer so that still left a lot to fix. The Acer C731 model's main fault was broken hinges, left or right.

The problem is poor construction and hinges getting stiffer. All the broken hinge units have been fixed by drilling 2 mm holes right through the lid (screen) and fitting 3 screws per hinge. Also fitted on the outside, an aluminium plate under the nuts to spread the load. The screws sticking out with nuts aren't the prettiest so black plastic covers have been printed to cover them.

It is obvious something has been done to each Chromebook but at least they won't break again.

The side that hasn't broken yet, a 1 mm drill was drilled right through and 2 mm from the outside to the nut. The screw screwed into the existing nut and a nut and plate was fitted to that not-yet-broken side too. If a hinge hasn't broken it means it will probably break sometime in the future.

That leaves a question, what is the best way to lubricate hinges?

[Edited the thread to add model name and issue detail]

Jack22

@Shedcomputerfixer

you can use silicon grease or a dry lubricant.

billsey

It's not the hinges that are breaking, it's the case halves. The 'thin and light' designs pretty much all don't have enough depth to hold the hinge mount screws well enough to survive poor handling practices. It's an endemic problem throughout the industry, not specific to the Acer models. The best solution I've found was rebuilding the hinge screw mounts with JB Weld. That adds a little to the weight but doesn't end up looking as bad as external screws would. You could also epoxy in steel plates with holes drilled and tapped for screws, but that takes a lot longer to get right.

Shedcomputerfixer

No, the case halves are not breaking, it is the wee nuts moulded into too small bits of plastic that fail. Not all Chromebooks have this problem.

Yes, epoxy moulding the hinge in can be done and one of them had been done that way. However, as said, time.

Getting silicon grease in isn't easy. One hinge I'd taken completely off, I undid the nut and that made it easier to rotate and the hinge did not fall apart. A 5 mm ring spanner is the tool that is needed to do it easily and quickly. Easing off the tension on all of the hinges would help.

Admittedly the nuts and plates on the outside don't look pretty and they now all have black 3D printed plastic covers. The covers almost look as if they should be there for some reason.

Basically, how to make things "bomb" proof, or as much as possible.