Triangle pseudo-Robertson screws [was Re: 5" floppy?.]

Tony Duell ard at
Wed Dec 3 14:16:18 CST 2008

> >> Actually, I once saw screws which looked a bit like Robertson (the
> >> square-socket kind) but with a triangular, not square, socket.
> > Those turn up on cheap domestic appliances over here.  The only
> > possile reason for them is to make the device difficult to repair,
> I disagree.  There is also an argument for them in the form of
> protecting consumers from the dangerous interiors of appliances.

And I'll disagree with the disagreement :-). I don't believe you should 
protect people from their own actions. If they want to get electrocuted, 
that's their business. The _real_ problem is that the person (if he 
lives) or his relatives then sues the manufacturer. The sooner such 
lawsuits are sent where they belong the better!

This is a particularly sore point with me as it's often used as a reason 
not to sell me spare parts and/or a service manual Of course you and I 
know I am more likely to do a safe repair if I have the exact spare part 
than if I have to guess characteristics and find something that 'should 
work'. I am more likely to do a safe repair if I have the service manual. 
But alas by not helping me the manufactuer can't be sued if I do 
something silly, so he's not going to provide parts/information. 

> Of course, depending on the appliance, this may not actually be a valid
> argument.  But if there's mains voltage present, it's an argument with
> some force to it.  (While you and I may be competent to fix things, and
> competent to avoid hurting ourselves even in cases where we aren't able
> to fix, most small-appliance consumers are neither.  Worse, many of
> them incorrectly think they are.)

I've got plenty of things (not computer-related) that are more than 50 
years old. None of them have any non-standard screws holding them 
together. Many of them contain mains and/or higher voltages. Live chassis 
(AC/DC) power supplies in valve radios and TVs were common. And yet I 
don't believe everybody who owned such a device ended up killing 
themselves trying to repair it. 

> Not that I think such screws are a good idea; like you, I come down
> opposing them.  Just pointing out that your "only possi[b]le reason"
> actually isn't.
> An Allen wrench of the right size should work.  The one device I ran

I've not found one that will fit well enough not to slip (and I have a 
pretty complete set of imperial and metric sizes).


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