Valve Core Remover

Presta-only valve core remover.

I finally got around to fixing the original issue thanks to a make by user cmh. I already knew it didn't work - but got lazy & never fixed it.

I referenced:
- https://grabcad.com/library/presta-valve-1
- https://grabcad.com/library/valve-core-tool-vc-1-1

Which are CADs done by Jared over at GrabCAD.

Referenced the Stan's tool only for general body dimensions.

I tried using my chain tool off a Topeak Ratchet Rocket on a removable valve core, & it works as claimed.

I took this measurement (4.1 mm across the flats) & remade that in my SLDPRT model.

Most other dimensions are non-critical to the function, so I left them as is.

Update 7 Aug 18: I added 3 more STLs. In total, they cover the spectrum of 8, 10, 11, & 12 mm ODs on the interface head. Hopefully this will address strength problems.

All other sections are hereby obsolete.