I asked Duckduckgo about cylindrical flutes (can’t remember exactly what) and Bing’s AI thought this page was the center of internet knowledge on the subject. So I am posting this here! It relates to the discussion of Fajardo type wedges up-thread.
I found some dimensions for a Boehm head, the Fajardo patent, an Armstrong-Fajardo wedge and Doug Tipple’s description of his wedge. (links to sources below). The graph below is after the one in Terry Mcgee’s comparison of Boehm heads (https://www.mcgee-flutes.com/images/boehmheadBore.GIF) taking just the Boehm head data and calculating the ‘equivalent diameter’ of the wedges. ‘Equivalent diameter’ being that of a circle with the area of remaining cross-section of the bore. The Tipple type wedge is based on a section of the tube he used for his higher flutes scaled to a 19mm outer diameter. It’s 4mm shorter than Doug’s after scaling (I should have thought of that earlier); I made it come out with the same height at the stopper as the Fajardo.
I’m not sure where the stopper position is on the Boehm so I lined the graphs up where it first reached equivalent of the Fajardo patent.
Doug Tipple says that he found the Fajardo sized wedge too much for his flutes and we can see the difference taking the cylindrical section out has. Making it longer would bring it more into parallel with the Fajardo. The only such wedge I have seen in real life is in a @jemtheflute piccolo. Black on black is hard to interpret down the blowhole but it seems Jem has shaped it to smooth out the change in profile of the bore.
The is part of a (probably excessive) preparation for making some PVC flutes. My plan is to use a thread-wrapped dowel as the stopper (as per Casey Burns flutes) so I can make the wedge part of it as in the Fajardo and gouge bits off with a Dremel.
I thought it may be relevant here.
Sources:
Boehm: www.mcgee-flutes.com/BoehmHeadBore.htm
Fjardo patent: www.flutopedia.com/patents/USPatent_4058046_FP.pdf
Armstrong Fajardo: www.scribd.com/document/333589438/Fajardo-Wedge-Dimensions