Machining Microwave Coaxial Low Pass Filters Part 1

Lathe work, milling and threading an aluminium cavity and coaxial stepped copper and brass central conductor for a high power microwave radio harmonic suppression low pass filter for 1.3 GHz/23cm. Without any actual help from Ghostbusters, sadly.
Don't try this at home as it won't work. The first 1 minute 17 seconds of this is almost entirely fiction, but I hope it's at least fairly genial and mildly fact-based laser ablation visual jollity.
These filters are a dream to machine, requiring high precision, but having a delightful simplicity. At VHF, UHF and microwave frequencies, lumped-element low pass filters aren't really ideal, Coaxial stepped filters can do a decent job at emulating a lumped filter.
Playlist of the whole series is at • 1.3 GHz Coaxial Low Pa...
The design process is similar to a version using coils and capacitors, but at microwave frequencies, the elements are sufficiently large in terms of wavelengths that there are serious fringing field effects that need to be handled in the design process.
Dominique's design sheet is at f1frv.free.fr/main3e_Filtres_L... (link is near the bottom of the page). It's in French, obviously, but Google translate works well on the site if you are not blessed with the gift of being Francophone.
Laser ablation at 1040 nm and Aluminium Monoxide vapour formation/absorption/emission at double that frequency around 520 nm are totally real, but sadly I'd need several kilowatts of laser power to use it and the Ghostbuster effect doesn't apply under The Rules (or Laws of Physics as the scientist spoilsports insist on calling them) and I'd end up boring my lathe and the wall and the neighbour's fence.
Extra points for anyone who spots all the film/book/music/popular culture references that are spattered generously throughout.
The ExoMol Atlas of Molecular Opacities, Tennyson and Yurchenko, Atoms 2018 arxiv.org/pdf/1805.03711.pdf
Visible aluminum monoxide emission during long pulse mid-infrared ablation of aluminum in air
Todd A. Van Woerkom, Glen P. Perram, Brian D. Dolasinski, Patrick A. Berry, and Charles D. Phelps
opg.optica.org/josab/abstract...
Journal of the Optical Society of America B Vol. 35, Issue 10, pp. B54-B61 (2018)
Image from Ghostbusters is (c) Sony Pictures I think, although it was originally Columbia. Go watch it if you've never seen it. Or even if you have.
In unrelated news, I've never seen Star Wars. Or any of the other Ghostbusters films.
Chapters:
00:00 Laser Ghostbustering
01:17 What's needed
02:40 So it begins
08:06 Reaming the Disks
13:40 Glue Chuck
15:43 The Block
21:36 The Big Hole
28:07 Boring Bar