I think you may be playing with the wrong parameter. The wire temperature
should be set to produce the maximum number of threads trailing the cut but
not so hot that it produces an orange peal texture to the cut. When you get
the temperature right leave it alone. I cut at a much higher speed with less
meltback and more wire sag. The foam pressure on the wire at a higher
cutting speed will dampen the ripples produced by melt back. So, try
increasing the weight on the pulley system till the ripples subside. Make
some tail surface cores for practise. They will be less expensive
experiments. You can tell when you have too much wire sag by the lack of
uniformity along the trailing edge.
Compared to what it costs to go to college these days, your "tuition" in the
form of ruined cores is a knowledge bargain.
Regards, Ollie
>I've hot wired spider foam several times with no problems. Tonight I
>just ruined 3 wing cores.
> The first core I used my normal temperature (about 9 inches in two
>minutes). I hot wire hands off using a weighted pulley system that cuts
>the taper automatically. It cut smoothly, no jumps or snags. It felt
>like a perfect cut. When I inspected the core, it had 1/8 inch ripples
>all over the core. Looked like a perfect sine wave. The second core I
>tried a cooler setting. Still big ugly ripples in the core. The third
>time I cut as hot as I dared without the wire snapping. More ripples.
>This foam is just too expensive to be tossing out 24 inch panels. Can
>someone help me get rid of these ripples? Power sanding is not an
>option. Thanks in advance. Rick Bothell Prescott Valley, AZ
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