Many of you have
requested that I add a page on making igniters. If you've read
about making your own electrical firing system, you know that
electrical igniters are necessary to make an electric current ignite
a fuse. This page will show you how.
These reliable
igniters can be made in just a couple of minutes and for only a few
cents apiece!
Method
1: Match Heads
MATERIALS
- drinking
straw
- book of safety matches
- hot melt glue gun and glue
- 4" strip of visco fuse
- Morning Glory-type sparkler (optional)
- Soldering equipment (iron, solder, and flux)
- Tinned coppel or nichrome ignition wire (see below)
- 2-conductor, 22 gauge wire (see below)
- Tape (electrical/duct/masking)
Notes on Materials
Nichrome (nickel-chromium)
is metallic alloy that is made into thin wires and used to make
electrical igniters in pyrotechnics. Very thin copper wire also
works for this purpose. Both of these (an sometimes a
copper-nickel alloy called coppel) can be bought from pyrotechnic
suppliers such as Firefox.
Personally, I find nichrome wire to be incredibly difficult to
solder, so I suggest using the Firefox 31 gauge "copel"
wire. Also, check out this
page which gives a list of different resistance wires you can
use.
The
22 gauge wire can be bought from a local hardware store. Make
sure that it has two separate wires, each with its own insulation.
Such wire can also be bought from Skylighter
in large rolls, which can also be used as shooting wire for your
electrical control panel.
Procedure
1. Cut
one foot sections from the 22 gauge wire. You will need
one section for each igniter you wish to make. Use a knife
or wire strippers to strip the insulation off of the last
quarter inch of the individual wires. Spread the bared
ends about a quarter-inch apart.
2. Cut a one inch
piece of nichrome or coppel wire. Wrap a quarter of an
inch around each lead of the 22 gauge wire, leaving a quarter
inch section to bridge the gap.
3.
Apply a bit of flux to the wires. Solder the
nichrome/coppel
wire to the bared leads of the 22 gauge wire to secure the
connection.
4. Use a knife to
cut a tiny chunk out of the end of a match head.
5.
Slip the nichrome/copper wire into the gap in the match head
that you just carved out. Bend the leads of the 22 gauge
wire down around the head of the match and down the stick,
making sure they don't touch (5a). Secure it with a
piece of tape (5b).
6. Cut a 1"
piece from the drinking straw. Insert the wire/match head
assembly into the straw so that the match head is approximately
1/3 of the way through. Take your hot melt glue gun and
fill in the gap between the wire and straw (6a-shown in
blue) with glue. Squirt a little bit around the outside to
make sure the wire won't come loose.
7. Take 2 or 3
matches (either 'safety' or 'strike anywhere') and cut off the
heads. Put the heads into the opposite end of the straw.
*optional* break open a
Morning Glory sparkler and pour just enough of the powder into
the straw to cover up the match heads (shown in tan). Do
not use black powder.
8. Cut one end of the
visco fuse at an angle to expose the black powder core.
Stick this end into the straw and down into the match heads (and
sparkler powder, if you chose to put it in).
Like you did earlier, fill the
gap between the fuse and straw with hot glue, squirting some
along the outside to secure the fuse into the straw.
The
finished product:
All
you have to do now is strip the opposite end of the wire.
Before you store these, be sure to twist together the exposed wire
leads - this ensures that there's no way an electrical source could
set off one of these igniters.
How
to Use
To
use these igniters, simply connect the piece of visco to whatever it
is you wish to ignite - be it another visco fuse, black match, or
quick match. See this
page for tips of how to connect fuse.
How
it Works
When
an electrical current (about 200 milliamps) flows through the
nichrome/copperl wire at the end, it heats up - much like the
filament of a light bulb. This ignites the match head.
The straw directs the flame forward, where it ignites the other match
heads and the temperature increases. This, in turn, will ignite
the visco fuse. All of this happens within less than a second.