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Date: Fri, 26 Apr 2024 16:36:54 -0400
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Subject: Re: OT: central limit theorem
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From: bitrex <user@example.net>
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On 4/26/2024 3:36 PM, John Larkin wrote:
> On Fri, 26 Apr 2024 14:46:52 -0400, bitrex <user@example.net> wrote:
> 
>> I have one of these inexpensive Ikea bookshelves for storing some of my
>> electronics books:
>>
>> <https://www.ikea.com/us/en/p/laiva-bookcase-black-brown-40178591/>
>>
>> I noticed the center shelf was starting to sag a few degrees. :( The
>> assembly manual specifies a weight limit of 33 lbs evenly distributed
>> which seemed like an oddly specific number. So I weighed the books on
>> the shelves, which aren't particularly well organized other than to
>> fully fill the available space widthwise on each shelf.
>>
>> A random assortment of hardbacks and paperbacks, some are tall and
>> skinny, some are short and fat. And each shelf was clocking in at 33 lbs
>> +/- 2 lbs.
>>
>> So I guess a heuristic for filling these shelves is just fill 'em up
>> then remove the heaviest book, and de-rate the center shelf by maybe 5-
>> 10 lbs because it's unsupported by a backing.
> 
> Composites, like the Ikea particle board, tend to sag. I got a nice
> barbeque table where the propane tank can sit on the lower shelf, but
> in a matter of days it took on a serous sag. It's some plastic
> composite.
> 
> Like many things that one buys these days, the first thing is to
> redesign it.
> 
> Add a center support of some kind.

They definitely have the "manufacturing" down to a science, though. I've 
assembled a number of their flat-packs over the years and I can't recall 
one that was ever short a part, or conversely, contained a single spare 
part.

Did Heathkit provide spares with their kits? Well, guess we know why 
they're out of business..