Black Hole
May contain traces of nut
I've been very stupid. I think this might be an example of "anchoring bias", but I'm not sure how to classify it:
I needed some ducting 150mm diameter. I knew it needed to be 150mm diameter. I spent about a day trying to find what I needed, but not knowing what to call it I ended up with search results for floppy fan vent ducting when I wanted something more rigid (but still bendable). It turned out Wickes had some, so I went to have a look and it wasn't the right thing.
Then I spotted a low-def image looking a bit different than the floppy stuff, and I traced that to an Amazon listing which looked about right, offered in a couple of lengths and diameters. For some reason (like: having a brain storm), I focused on the 5.1" diameter version when I know full well that 5" is not (roughly) 150mm! What's more, it even said "(130mm)" in the listing, and I just dismissed that as a typo!!
Of course, when it turned up, I immediately realised it was too small and what I had done. Fortunately, being Amazon, I could easily arrange return and order the right one (5.9").
I am trying to explain how a life-long engineer can make such a fundamental mistake. I convinced myself 130mm must be an error in the listing. I think it might have been the combination of relief having found the right thing after a long search, and a rush to get an order in for next-day delivery. Basically, I scammed myself without external influence.
I needed some ducting 150mm diameter. I knew it needed to be 150mm diameter. I spent about a day trying to find what I needed, but not knowing what to call it I ended up with search results for floppy fan vent ducting when I wanted something more rigid (but still bendable). It turned out Wickes had some, so I went to have a look and it wasn't the right thing.
Then I spotted a low-def image looking a bit different than the floppy stuff, and I traced that to an Amazon listing which looked about right, offered in a couple of lengths and diameters. For some reason (like: having a brain storm), I focused on the 5.1" diameter version when I know full well that 5" is not (roughly) 150mm! What's more, it even said "(130mm)" in the listing, and I just dismissed that as a typo!!
Of course, when it turned up, I immediately realised it was too small and what I had done. Fortunately, being Amazon, I could easily arrange return and order the right one (5.9").
I am trying to explain how a life-long engineer can make such a fundamental mistake. I convinced myself 130mm must be an error in the listing. I think it might have been the combination of relief having found the right thing after a long search, and a rush to get an order in for next-day delivery. Basically, I scammed myself without external influence.
