[ajsnigrutin]

This really depends on many factors.

Will you be able to get those parts, how fast and how cheap, and how easy/hard is it to replace them? Garage door, maybe... it's an expensive thing... you'll investa lot of time/effort to get it fixed... buta battery powered drill? No way to get the parts. Someone mentione 3d printing... can you imagine some average drill owner designing a part for 3d printing, buying a 3d printer, going through the learning curve to get a usable part.. for a $50 drill? No way. Just having someone open it up to replace it is more expensive than the drill itself. On the other hand, you could pay 20 cents more when buying and got a long-lastin metal part.

If you want a part to fail to not cause greater damage, add some kinf of a standardized fuse to it, or detect the overload and stop it, before it fails. Yeah, sure, something is going to fail at some time (nothing lasts forever), but treating plastic gears that break (instead fo $1 more expensive metal ones) as a good thing,.. i have to disagree with that.

[jkestner]

Underrated is ordering SLS parts from a printer, like on CraftCloud. You can get small functional nylon parts made for $2 + shipping.

Modeling things has always been the biggest friction point. Not easy to make CAD interfaces easier. Part files from the manufacturer would be nice.

[ajsnigrutin]

Sure, but you still have to either open the device yourself, or pay someone to do it, find the broken part, find the part design, order it, ship it, replace it, and reassemble the device. If you don't do it yourself, it's not worth it at all financially, and if you do, it's quite a long process, usually not worth it for a $50 drill, where the company wanted to save a few cents with a plastic part.

[jkestner]

Oh yeah, overall, I don't think 3D printers are useful for this in the real world, not at this point. Just playing to the crowd, for those HNers determined to make use of 3D printing.

Nothing beats simply designing to repair, or at least YouTube how-to videos, and available replacement parts. I've kept a stupid $100 microwave going for 15 years with two $4 repairs, mostly for the principle of it.

[btbuildem]

One could find the part design in a library, and print it at a coop hackerspace or order it online off some pay-per-print shop. It doesn't have to be as complicated as you put it.

[ajsnigrutin]

But it's a $50 dollar drill, that failed due to a cheap part.

I don't know where you live, but just a diagnosis by a repair technician is more expensive than that. Even if you open it up yourself, find the broken part, find that part someone, get someone to print it,get the part delivered, and replace it, it'll be more than $50 of associated costs... and just because a company wanted to save 50 cents on a plastic gear.