7 Dec
2014
7 Dec
'14
12:47 p.m.
Does anyone have instructions or a schematic (or a pointer to a URL)
on how to make a "hot wire" device to cut the PVA bond between a CRT
and its safety lens? What kind of power supply (how much power), "hot
wire," etc.?
I'd like to build one of these "hot wire" devices, *safely*.
Thanks,
Bob
7 Dec
7 Dec
1:48 p.m.
On 12/07/2014 11:47 AM, Bob Vines wrote:
Does anyone have instructions or a schematic (or a
pointer to a URL)
on how to make a "hot wire" device to cut the PVA bond between a CRT
and its safety lens? What kind of power supply (how much power), "hot
wire," etc.?
I did this on a CRT from an HP 250 a number of years ago. If I remember
right, the CRT face is around 10"x12", so the shorter dimension's perhaps a
bit less than a typical screen. I just used the 12V from a spare PC PSU
that was kicking around (with a dummy load on the 5V so that it would
regulate OK) and some resistance wire.
I'm afraid that I don't recall the wire characteristics - but there was
just enough heat to do the job if I took things slowly (and that's likely
preferable to something which would be faster, but could possibly be
dangerous due to increased heat).
I suspect that something with a slightly higher voltage (~15V ?) and run
via a wire-wound rheostat for control would be the way to go if you're
doing this more than once.
cheers
Jules
2:09 p.m.
On 12/07/2014 11:47 AM, Bob Vines wrote:
Does anyone have instructions or a schematic (or a
pointer to a URL)
on how to make a "hot wire" device to cut the PVA bond between a CRT
and its safety lens? What kind of power supply (how much power), "hot
wire," etc.?
Do an internet search on "hot wire foam cutter". You'll turn up several
DIY YouTube videos, Instructables and even low-cost retail ones.
Take your pick--it's neither difficult to make you own or expensive to
purchase one.
--Chuck
8:05 p.m.
Many years ago I worked with an improvised hot-wire foam cutter, used to
cut 4' thick EPS (Styrofoam) slabs. The wire itself was around 6' long, and
ran vertically.
The electrical side consisted of only the ni-chrome wire, a Variac, a fuse
or CB and AC wiring. Whoever spec'd out the thing chose a wire that, at 6'
long, was fine with somewhere between 20V and 120V AC - I never really
noticed where the Variac was set, somewhere mid-range though.
On the top end, the wire was attached via a long-ish turnbuckle to an
insulator secured to a ceiling truss. The hot wire penetrated the work
surface (a table made of two 4x8 sheets of plywood) near the center
(passing through a metal guide plate with a small hole) and was firmly
secured somewhere beneath. The turnbuckle up top was used to set tension on
the wire.
On Sun, Dec 7, 2014 at 1:09 PM, Chuck Guzis <cclist at sydex.com> wrote:
On 12/07/2014 11:47 AM, Bob Vines wrote:
Does anyone have instructions or a schematic (or
a pointer to a URL)
on how to make a "hot wire" device to cut the PVA bond between a CRT
and its safety lens? What kind of power supply (how much power), "hot
wire," etc.?
Do an internet search on "hot wire foam cutter". You'll turn up several
DIY YouTube videos, Instructables and even low-cost retail ones.
Take your pick--it's neither difficult to make you own or expensive to
purchase one.
--Chuck
8:34 p.m.
On 12/07/2014 05:05 PM, drlegendre . wrote:
On the top end, the wire was attached via a long-ish
turnbuckle to an
insulator secured to a ceiling truss. The hot wire penetrated the work
surface (a table made of two 4x8 sheets of plywood) near the center
(passing through a metal guide plate with a small hole) and was firmly
secured somewhere beneath. The turnbuckle up top was used to set tension on
the wire.
I've got one in my shop made with stainless steel music wire and a bent
hacksaw blade for tension. A cheap triac dimmer feeds into an old
filament transformer. Not as grand as yours, but it does get the job done.
--Chuck
9:54 p.m.
@Chuck
Why did you need the filament xfmr? Was the hot-wire so low in resistance?
Curious about the bent hacksaw blade tensioner.. was it bent in a zig-zag
fashion, approximating a spring of sorts, using the holes on each end to
connect it?
On Sun, Dec 7, 2014 at 7:34 PM, Chuck Guzis <cclist at sydex.com> wrote:
On 12/07/2014 05:05 PM, drlegendre . wrote:
On the top end, the wire was attached via a long-ish turnbuckle to an
insulator secured to a ceiling truss. The hot
wire penetrated the work
surface (a table made of two 4x8 sheets of plywood) near the center
(passing through a metal guide plate with a small hole) and was firmly
secured somewhere beneath. The turnbuckle up top was used to set tension
on
the wire.
I've got one in my shop made with stainless steel music wire and a bent
hacksaw blade for tension. A cheap triac dimmer feeds into an old filament
transformer. Not as grand as yours, but it does get the job done.
--Chuck
10:33 p.m.
On 12/07/2014 06:54 PM, drlegendre . wrote:
Why did you need the filament xfmr? Was the hot-wire
so low in resistance?
The distance between the wire end-points was probably only 6-8 inches.
So, yeah, the resistance was really low.
No zig-zag on the hacksaw. just gently bent in a somewhat asymmetrical
U shape--one end fastened to the work "table" and the other to one end
of the wire.
--Chuck
15 Dec
15 Dec
5:39 a.m.
ahum:
lmgtfy.com/?q=hot+wire+diy#
:-)
On 07-12-14 18:47, Bob Vines wrote:
Does anyone have instructions or a schematic (or a
pointer to a URL)
on how to make a "hot wire" device to cut the PVA bond between a CRT
and its safety lens? What kind of power supply (how much power), "hot
wire," etc.?
I'd like to build one of these "hot wire" devices, *safely*.
Thanks,
Bob
--
Met vriendelijke Groet,
Simon Claessen
drukknop.nl
3507
days inactive
3515
days old
7 comments
5 participants
participants (5)
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bobvines00＠gmail.com -
cclist＠sydex.com -
drlegendre＠gmail.com -
jules.richardson99＠gmail.com -
simski＠dds.nl