On Mon, 31 Dec 2012 16:00:10 -0700, you wrote:
>Actually, the one I saw was the small hole saw version - there was an
>island of copper left around the hole, and then a cut out ring around that.
>I guess either method would work, but interesting to see the tool that does
>that.
>
>I've also not seen anyone mention wirewrap in this thread. That's another
>alternative - just get coperless predrilled board, and use wirewrap. I've
>actually done a couple projects with wirewrap, and I was using a completely
>manual wrapping tool (looks like a jewelr's screwdriver), and it was pretty
>good. With a wrapping gun (which i have now), it would be even faster, but
>haven't built anything complicated enough to warrant wirewrapping in a
>while now. I also have a commercial Sony radio from the 70's that's
>wirewrapped, and soldered. Guess at that time, manual labor was more
>economical than PCB manufacturing.
Actually, there were several methods of assembly. Wirewrap used #30
(or #26) Kynar wire, various sized posts, unwrapping tools, wrapping
tools, and so on. The main problem was making corrections and the
cost of the sockets. A board with pins in an array was very very
expensive. IIRC, you could probably get away with about 10 Mhz at the
maximum.
Commercial wirewrap stations used precut wire, in bins (they had a
machine that cut the wire, stripped it partially, and did so to a
precise length) with lights on them, and an XY plotter arrangement
that moved the wirewrap gun to the appropriate coordinates. The
operator picked a wire from the bin with the light lit, put it in the
gun, and pushed the gun down over the pin. Squeeze the trigger and
it's wrapped. Push a button and the wrapping gun is moved to the next
location. Put the end of the wire in the gun, and you've got a
connection.
Was used for military equipment in the 60's, 70's and 80's I think.
Termipoint was similar, but used stranded wire and a rectangular pin
(could not be wirewrapped). The stripped wire (about 1/8 inch) was
placed against the pin and a clip was forced over the pin and wire,
making the electrical contact. Wirewrap stripped the wire to about 1
inch, and wrapped it around the pin at high speed. The pressure
welded the wire to the pin and made a gas tight joint. Not at all
sure if it made specs if you unwrapped it and did it again.
Never did much termipoint, but saw examples. Did a lot of wirewrap,
still have the bits and tools.
Harvey
>
>
>On Mon, Dec 31, 2012 at 2:26 PM, Pict <pict@...> wrote:
>
>> **
>>
>>
>>
>>
>> On 31/12/2012 22:56, "Andrew Hakman" <andrew.hakman@...> wrote:
>>
>> >>There used to be a small tool that was used to create an island around
>> >>a drill hole. it was effectively a micro sized hole saw. The
>> >>technique was to drill holes in copper clad where you wanted them,
>> >>isolate this hole with the tool (as needed) and then bridge from
>> >>island to island with the parts.
>> >
>> >I've seen boards built with this. Usually the pre-drilled proto board, but
>> >with copper tracks that run from one edge to the other, and you separate
>> >the rows into smaller sections with the little hole saw, but I've never
>> >seen the tool. Have any info on it?
>>
>> I think you are thinking of Veroboard and a tool like this to break the
>> tracks
>> http://www.ebay.com/itm/300816579317
>>
>> A small drill bit works almost as well. This tool does not create an
>> island of copper, it clears the copper strip away around the hole and
>> breaks the strip into two sections.
>>
>> Regards,
>> John
>>
>>
>>
>
>
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