Re: "Barrel" connectors

Don Y <blockedofcourse@foo.invalid> wrote:

We have frequent need (many times each week) to match devices to
"suitable" wall-warts/bricks.  *I* do this with a dial caliber
and drill bits -- and a bit of math.
 
I need a scheme where "less skilled" (e.g., developmentally disabled)
folks can do this *reliably*.  Even if I have to spot-check their results.
 
I'm thinking of just buying one of every connector and mate, labeling
them, putting them on a "key ring" and then just having folks fumble
around until they think they've found suitable mates.
 
The downside is that there are cases where a connection may *appear*
to "fit" but isn't truly appropriate.  E.g., ID is a bit oversized
(or undersized, depending on your point of view).
 
Is there a better way?
 
Are there any other *mechanical fitting* issues that I may have
overlooked (obviously, there are electrical issues)?

The trouble with 'just try it' is that the 'trial' sockets can wear over
time.  eg if you insist on putting a 6mm OD plug into a 5.5mm OD socket,
it might go but bend the spring contact.  Eventually the 5.5mm OD plugs will
feel loose because the contact is now bent out of place.

Also you might have a plug that securely fits the OD but it has too large a
hole in the inside so it's a poor fit.  I've previously killed equipment
like that (2.5mm plug on a 2.1mm socket -> poor contact -> voltage drop ->
switching converter has to pull more current to keep up -> fried something).

I think a series of drill bits to measure the ID is a good plan, then maybe
there's some way to measure the OD while getting 'acceptable' tension on the
spring?

Theo