"Pete C." wrote:
>
> Stars, hearts, etc. would make interesting designs. One thing you need
> to keep in mind is that the mechanism doesn't provide any way to change
> the drive ratio between the two substances, so you need to maintain the
> same ratio of core area to exterior area, regardless of the pattern, or
> you will have issues with under filling one area relative to the other.
> It looks like the ratio is 50/50.

No, it's more like 60/40. The masa chamber is bigger.
The drive ratio is fixed, so you are correct that the
ratio will have to be strictly observed. Thanks for
pointing that out, I hadn't considered that. That
means I won't be able to have a selection of nozzles
of different diameter.

Mark Thorson wrote:
>
> "Pete C." wrote:
> >
> > Stars, hearts, etc. would make interesting designs. One thing you need
> > to keep in mind is that the mechanism doesn't provide any way to change
> > the drive ratio between the two substances, so you need to maintain the
> > same ratio of core area to exterior area, regardless of the pattern, or
> > you will have issues with under filling one area relative to the other.
> > It looks like the ratio is 50/50.
>
> No, it's more like 60/40. The masa chamber is bigger.

50/50 or 60/40 is pretty difficult to distinguish in those pictures.

> The drive ratio is fixed, so you are correct that the
> ratio will have to be strictly observed. Thanks for
> pointing that out, I hadn't considered that. That
> means I won't be able to have a selection of nozzles
> of different diameter.

Any CAD program can calculate the area of the two sections as you scale
the nozzle, so it shouldn't be too difficult to make a star, heart, etc.
and scale it until the ratio is correct. You probably also don't want to
machine a tube, but rather machine a mandrel that the the tube can be
pressed / hammered around so it has the correct profile without excess
thickness to the outside material will flow in the correct matching
pattern.

"Pete C." wrote:
>
> Any CAD program can calculate the area of the two sections as you scale
> the nozzle, so it shouldn't be too difficult to make a star, heart, etc.
> and scale it until the ratio is correct. You probably also don't want to
> machine a tube, but rather machine a mandrel that the the tube can be
> pressed / hammered around so it has the correct profile without excess
> thickness to the outside material will flow in the correct matching
> pattern.

Good point. That is the right way to do a precision shape.
If the tube were thin enough and made out of brass or
something more ductile than steel, I might be able
to make a crude star by grabbing the edge with
needle-nose pliers and twisting it to form a point.