Intermittent Helix

[r***@hotmail.com]

Hi All,

I am trying to model a tube that has a helical cut in it, axially,
going through the entire wall thickness (to end up with a spiral cut
down outside of the tube.

That's no big deal, but where I have trouble is that the engineers
want the cut to be intermittent. They want the cutter to follow the
helix, for 270 degrees of rotation, then stop cutting for 20 degrees,
then start cutting again for another 270 degrees for the entire length
of the tube. They also want the helix to have a variable pitch, and
they aren't real sure just yet how many degrees of "cutting" and
"stopped cutting" they want, so it could vary, depending on how the
tube behaves after some samples have been made.

I created a helix to run the length of the tube as a reference. I
then started a 3d sketch, converted entities on the helix, trimmed it
where the 270 degrees would stop, and made a sweeping cut. This
represents the first cut. That's all fine and dandy, but I can't
figure out how to make multiple cuts without making each one
individually. With the possibility of the degrees changing is there a
more appropriate way of doing this? Is there a way to do a linear
pattern that rotates at the same time? Or, maybe a curve driven
pattern or something?

Please help! (I'm using SolidWorks 2006.)

Relz

[FlowerPot]

Post by r***@hotmail.com
Hi All,
I am trying to model a tube that has a helical cut in it, axially,
going through the entire wall thickness (to end up with a spiral cut
down outside of the tube.
That's no big deal, but where I have trouble is that the engineers
want the cut to be intermittent. They want the cutter to follow the
helix, for 270 degrees of rotation, then stop cutting for 20 degrees,
then start cutting again for another 270 degrees for the entire length
of the tube. They also want the helix to have a variable pitch, and
they aren't real sure just yet how many degrees of "cutting" and
"stopped cutting" they want, so it could vary, depending on how the
tube behaves after some samples have been made.
I created a helix to run the length of the tube as a reference. I
then started a 3d sketch, converted entities on the helix, trimmed it
where the 270 degrees would stop, and made a sweeping cut. This
represents the first cut. That's all fine and dandy, but I can't
figure out how to make multiple cuts without making each one
individually. With the possibility of the degrees changing is there a
more appropriate way of doing this? Is there a way to do a linear
pattern that rotates at the same time? Or, maybe a curve driven
pattern or something?
Please help! (I'm using SolidWorks 2006.)
Relz

Make the entire cut with the complete helix, then use additional
extrudes or revolves to fill in parts of the cut as needed. This is
simpler than trying to make several more complex swept cuts.

Why has Jon Banqueer failed to answer this question? Huh? Why jon? Why
do you so arrogantly refuse to tell the truth and answer this guy's
question? Gonna go for multiple contexts on this too? Since you are self
proclaimed keeper of all truth on the internet, I expect you to answer
all these questions with better answers than anyone else. Why won't you
do it? Are you afraid of the truth? Are you afraid someone might
discover the truth about you? That you're a stupid poser, ad-quoting
wannabe?


Daisy.