Tormato! Tomato Cage With Trellis and Nutrient Delivery System

Step 3 Measure!

Measure and mark for the drilling of holes. If you are going to be putting an end cap on for the trellising system, mark 3 inches from the top of the PVC. All measurements will then go from here. If you are not planning on doing the trellis, skip this steps and all measurements will be made from the end of the PVC. I highly recommend not skipping this step...even if you're not using the trellis now, you may want to try later! You can space your spirals as close or as far as you would like them. I find somewhere between 8 and 11 inches produces the best Torsion/Tension on the pex tubing.

For those who would like to get technical, here are some equations. I have no idea what they mean, so don't ask for any explanations. I only know that it is for a helix, and that is what the tormato is.

The helix is a space curve with parametric equations
x = rcost
(1)
y = rsint
(2)
z = ct
(3)

for t in [0,2pi), where r is the radius of the helix and 2pic is a constant giving the vertical separation of the helix's loops.]

The curvature of the helix is given by
kappa=r/(r^2+c2),
(4)

and the locus of the centers of curvature of a helix is another helix. The arc length is given by
s=sqrt(r^2+c2)t.
(5)

The torsion of a helix is given by
tau=c/(r^2+c2),
(6)

so
kappa/tau=r/c,
(7)

which is a constant. In fact, Lancret's theorem states that a necessary and sufficient condition for a curve to be a helix is that the ratio of curvature to torsion be constant.

The osculating plane of the helix is given by
|z_1-rcost z_2-rsint z_3-ct; -rsint rcost c; -rcost -rsint 0|=0
(8)
z_1csint-z_2ccost+(z_3-ct)r=0.
(9)

The minimal surface of a helix is a helicoid.