[sdiy] Cutting Wire to Length

[Tom Bugs]

Thanks for some fascinating info today from various people & sources.

I think the main choices are:
- off-the-shelf machines - not cheap.. hard to tell whether budget 
models would be suitable.
- DIY machines - unfortunately I really doubt I have time to make 
something & get it working precisely
- out-source.. - certainly works for regular cabling needs.

I should actually describe how I actually do do it at present - yes, the 
ruler is involved but also..
- typically I use 2/3/4 strands of different wire
- for power cables where rough length 7" is OK I stretch these out long, 
then grab and double the strands over - giving c.2M split in two - cut 
the bend.
-- repeat this doubling over, snipping at each bend - do this a few 
times, then you have a healthy bunch of cables to snip some lengths off
-- the only thing to note is to keep the same batches together so 
lengths are the same.
Or - I measure the first bit and then carefully bend over matched 
lengths - kind of fiddly - add on a little and then trim once you've 
grouped several strands.

Yeah.. both are fiddly..



On 26/02/2014 20:49, ASSI wrote:
> On Wednesday 26 February 2014, 09:20:17, Tom Bugs wrote:
>> Is there some sort of tool / arrangement that strips off a precise
>> length of wire (talking cm&mm lengths typically)
>> .. preferably not something costs several thousand £/$!
> I can't give precise details because I last used this thing close to 30
> years ago, but this is something that probably isn't too difficult to build
> if you have access to some mechanical workshop.  Sorry, I have no idea what
> to call that in German, much less English…
>
> The mechanism was that the wire is pulled/pushed through some traction
> wheels (that'll also straighten the wire coming off the spool) and after a
> certain amount of rotation a cutting wheel is engaged.  A small gearbox and
> a few stop plugs that you could move around the circumference of the crank
> wheel allowed to set up all wirelengths above about 3cm in a matter of a few
> seconds.  The gearbox was designed so that you would get one cut for each
> revolution of the crank  for most settings (and there was a mechanical
> counter on the cutting wheel so you didn't need to keep track of how many
> you already had).
>
> We had a more complicated variant of that machine that would twist two wires
> before cutting them, you could also adjust how many twists you got per cut
> so that the impedance would come out right.  That one was a little tricky to
> set up so that the cut would be exactly inbetween two twists, but once
> you've had that down you could just keep cranking.
>
> If you don't need several hundred pieces of each length and don't mind
> little bits of waste (literally), you could just wrap the wire across two
> rows of steel pins that you can mount different distances from each other
> and then chop it.
>
>
> Regards,
> Achim.

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