Smitty Two wrote in message
news
In article ,
"N_Cook" wrote:

Smitty Two wrote in message
news
In article ,
"N_Cook" wrote:

For high temp applications. The type I have has 2 parts to the PTFE
insulation. The outer strips off easily with any old wire stripper,
but
however new , gap limited cutters , will not cut the underlying
PTFE.
Outer is double spiral wound PTFE sheet/ribbon I think, heated to
lock
together to a certain extent. The inner is more fibrous in nature.
Cutting
the remaining inner material , even difficult with a razor. The only
technique I've found, is remove the outer as normal , then .5mm
grinding
disc in a Dremmel , only just touching, run all around and then pull
off,
rarely cuts a wire strand . Other than some mega-buck NASA/Mil
approved
cutter any other ideas?

The type of stripper shown he


http://rocky.digikey.com/weblib/OK%2...hoto/ST-500.jp
g

is pretty good with teflon. Sold under various brand names, and also
in
different adjustable gauge ranges or in fixed sizes.

For teflon, squeeze fully to cut through insulation, then back off
very
slightly to pull off slug.

Thats the type I use.
I think I'll make my own cutter, a pair of razor blades set with a
tapered
gap between cutting edges (gap a bit larger than ext diam down to wire
diam). Push the wire down the gap in 2 orthogonal directions and then
rotate
round at the narrow end. Then sleeve should slide off easily as its the
cutting completely around that is the problem. I'd rather avoid melting
of
PTFE (the fluoro bit) especially as it cuts so easily.
Hopefully something like a minimal version of these PTFE specific
cutters,
I only have one drum of one size of this wire, so no adjuster needed


http://int.rsdelivers.com/product/rs...091-45mmdia-cu
tting/0608301.aspx

http://docs-europe.electrocomponents...6b8001b254.pdf

Glad your home-made gadget worked, but the cutters I referenced are the
ones we use every day for stripping teflon. I'm surprised they wouldn't
do it for you. It does take a bit of technique as noted, setting depth
to cut fully through, then backing off pressure to remove slug. The 90
degree rotate and 2nd cut helps, but for production work is too slow.


This wire is very fine filament multistrand. perhaps 30 wire strands. If it
was solid conductor it would be easier to strip. But the main problem is the
multiple thin sleeve layers , perhaps 3, under the thick outer sleeving.
PTFE seems to be strong in one sense and transverse very weak. If the fibrey
part was laid up transversely it would easily part at the cutting point, but
the layup is strong axially.