Fritz:

On tight curves, you could be spinning the wood without the blade being
at the center of the spin. Hard to explain with just text typing in this
newsgroup. But as you cut the arc, or tight corner, the blade needs to
be at the dead center, so the teeth have no force to twist. If a
twisting force does happen, then the teeth will catch on the kerf wall of
the metal and a slam pop will occur. A Slam Pop with more force than
your fingers can hold down against. Again, just a problem that can be
solved with practice.

Look around the web, there are scroll saw practice patterns around, or
even puzzle patterns that can be glued to scrap hardboard or cut-off
scraps for practice cutting. Scroll sawing is all about eye-hand co-
ordination moving the wood (metal) past the blade free hand style.

Good luck.

(I am presuming you are using a very high tooth count metal cutting blade
with no skips. And a quality blade at that. Pike jewelry cutting
blades, and Flying Dutchman's metal cutting are two brands of very high
quality metal cutting blades. Just like in Band-sawing, minimum teeth in
contact with the metal is 3 teeth at all times. 1mm aluminum no
exception to 3 teeth rule.)

Phil