We started with some 100×25 Oregon, ripped in down to 50×25. Here I’ve chopped four 1600mm lengths to form the sides of the pyramid/obelisk. We found a nice looking christmas tree on Google Images then used a graphics package to measure the angle – turns out that 80° from horizontal was the angle we thought looked good.
Some simple trigonometry gave us the size of the base (close enough to 500mm), to get the angle we wanted. Some more 50×25 oregon and various offcuts from the mitre saw gave us a base.
We braced it up for strength, since I planned on placing one or two concrete blocks onto the base to weight it down. (We get strong winds around our place).
Some 7mm holes and M6 bolts attached the ‘legs’ to the base. Forgot to allow for the 25mm offset from the ends of the pieces of wood, so our angle won’t be quite correct.
A very sophisticated (not) mechanism fastened the top together. One zip-tie.
Here’s the result so far, with a human for size comparison.
Chicken wire! Messy stuff to work with, but a compressed air stapler made it easy to pin it down. We only put wire over three sides, leaving the fourth side open to allow placing concrete blocks (for weight) and christmas tree lights (for pretty).
We put it up on an earth bank overnight, to check it wouldn’t blow down.
Barbara fitted the lights through the chicken mesh. Took quite a while. Here we ran a quick test in a darkened room. Looking good!