I needed a new shopping basket. The old one had broken down after many years of abuse. In the process it killed a cheap bottle of red wine, which made a nice big puddle on the floor, much to the delight of the shop’s staff. Fortunately the incident didn’t cost me anything.
The replacement looked pretty much the same as the old one and cost 4€. It looked sturdy enough.
I was wrong.
After about ONE WEEK of mild usage, exposure to lower temperatures (about 10°C or so), one of the handles just snapped. I swear I didn’t pour liquid nitrogen over it.
The mechanically inclined will notice that it snapped at a spot, which could be called “stress riser”, where the thinner & presumably more flexible part joined the geometrically reinforced stiffer part of the handle. We need SMOOTH transitions to avoid harsh reactions, not step-changes! BTW, the same holds for optics and transmission lines, it is a very common thing and should be well-known to anybody involved in a design process of any kind.
1st attempt to fix it:
This went reasonably well. However, I soon discovered that I had inadvertently snapped yet another bit, a crucial one.
That failure was unacceptable. I didn’t want to kill yet another bottle of red wine. A change of course was necessary.
I decided to keep the strongest parts of the handles (hand-piece) and replace the crappy parts with strong strings. While chopping off the useless parts, I discovered that the plastic was extremely happy to snap, once stressed beyond its narrow be-happy zone. Poor quality stuff.
The finished product:
Not happy about it, but I certainly wont spend another 4€ for a replacement of the same kind. Yes, I should probably add a couple of knots to keep the string from slipping under heavy load, but not today.