Quickie Q2 Lite Construction Manual - page 26
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The variable voltage control can be obtained from Aircraft
Spruce and Specialty or Wicks Aircraft Supply, or you can substitute
any controllable power supply to include the 14 to 20 volt range with
at least 4 amp capability. An alternative is to borrow two 12-V
battery chargers or auto batteries and lash up the following device.
The "A" blocks represent either a battery or a 12-V dc battery charger
with a 4 amp capability.
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The cutter should only be used on the blue-white or orange
styrofoam. A hazardous gas is emitted if you try to cut urethane.
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You can substitute .025 nicrome wire which can be run at a lower
current (about 2 amp) but nicrome wire is difficult to find. Adjust
the current to obtain a wire temperature which will allow the wire to
cut the foam at a rate of one inch every four to six seconds when
pulled with a light load (less than ! pound). This can be checked with
a small scrap of foam. If temperature is correct, the foam will have
smooth hairy surface. A cratered surface means too much heat. If the
wire is too cold, the cutter will have to be forced hard, causing the
wire to lag. Lag should not exceed 1 inch over the top and bottom of
the wing and not over 1/8 inch around the leading edge. If the wire is
too hot, it will burn away too much foam, making the part too small
and will result in ruts in the foam if the wire is inadvertently
stopped during cutting. The wire should be tightened until the wire
starts to yield. Check this by tightening the wire while plunking it,
listening to the sound. The pitch will increase until the wire yields.