Path: ...!weretis.net!feeder9.news.weretis.net!feeder8.news.weretis.net!eternal-september.org!feeder3.eternal-september.org!news.eternal-september.org!.POSTED!not-for-mail
From: Bill Sloman <bill.sloman@ieee.org>
Newsgroups: sci.electronics.design
Subject: Re: OT: central limit theorem
Date: Sat, 27 Apr 2024 16:40:54 +1000
Organization: A noiseless patient Spider
Lines: 35
Message-ID: <v0i6m6$7i9l$1@dont-email.me>
References: <662bf69c$0$8484$882e4bbb@reader.netnews.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 7bit
Injection-Date: Sat, 27 Apr 2024 08:41:11 +0200 (CEST)
Injection-Info: dont-email.me; posting-host="ed6391414cc97d0f2d2ab7e9ae7a3313";
	logging-data="248117"; mail-complaints-to="abuse@eternal-september.org";	posting-account="U2FsdGVkX1+gtpyiTjzKlSkOhY7itVo8HW3Rfk76LgI="
User-Agent: Mozilla Thunderbird
Cancel-Lock: sha1:jhdgsuj9l5t40bsD5LXZKOCqrbQ=
In-Reply-To: <662bf69c$0$8484$882e4bbb@reader.netnews.com>
Content-Language: en-US
Bytes: 2719

On 27/04/2024 4:46 am, bitrex 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.

Or put on a backing sheet and knock some nails through the backing sheet 
into the shelves. It isn't elegant. I've built bookcases where I've 
rebated the frame so that the backing sheet didn't show when viewed from 
the side, but my wife thought that this was more trouble than it was worth.

We owned a lot of books and the default bookshelf was mounted on 
brackets screwed into plugs let into the wall. I'd had a masonry drill 
even before we got married.

My great-grandfather would have been scandalised. I've now got the 
glass-fronted bookcase he built to complete his joinery apprenticeship 
some 150 years ago, and it is much more elegant piece of work.

-- 
Bill Sloman, Sydney