The focussing array is them six "whiskers". I have tried a number of methods for fixing them.
For the first pylon I built, I went with magnets (two per). Unfortunately, they were not that strong and I ended up with some droopy whiskers. So at the last moment I added a pin (that's the whisker to the left below). For the second pylon, I went with two pins and no magnets (right, below). This one makes for a sturdy link, however each time I put the whiskers on I'm a bit concerned that I'll damage the holes.
For the third pylon, I decided to go back to magnets – because if I can't magnetise something, I get that very annoying feeling that I've failed somehow. This time around however, I went with rod magnets (1/8" x 1/4"), so I get the benefits of pins as well. So far, so good…
So yes, it's been a while, but at long last I've been making progress. The thing with pylons is, they're big. If you want to take them with you, you pretty much have to go flat-packed. Like so:
On the pylon side, I drilled 3 roughly equidistant holes, glued the magnets in, waited for everything to dry, and then added a spot of paint on top of the magnets. I pressed the other part while the paint was wet, which gave me the place to drill…
… I then drilled where the paint was, put on more magnets (taking care I got the polarity right), and here we are:
While I was at it, I assembled the centre of the pylon: glued the 3 parts together, then added 1mm brass rod in 4 places. The rod is not flush, the idea is to fill the hole with a bit of green stuff. It was quick to do, and ensures the thing will not break apart. The joint in the middle will be filled with green stuff as well - easier than spending time trying to get the two parts fit exactly.
So it's been a long while, but at long last I'm back with the pylon. First step is to build the base. I've pinned the legs, using a cunningly crafted template to ensure the holes match on both sides. It certainly helps speeding things up too, as this needs to be repeated for all 6 legs.
One side of the template is marked 'hub', the other 'rim', to help ensure I don't drill the holes the wrong way around. An alternate method would be to drill the guiding holes in the exact centre of the template, but I could not be bothered.
And that's all for now.