Updated for 3mm filament and fittings.

Needs sizing for fitting nut and possibly thicker top.

Signed-off-by: Matthew Schick <mschick@redhat.com>
Should be usable now

* Updated fitting_diameter to match threads on pneumatic fitting
* Removed bevel from top of body, need the extra bulk to hold the fitting
* Added just a little bit of heighth to the jhead cut (was a litle too tight on
  my test print)

Signed-off-by: Matthew Schick <mschick@redhat.com>
Better spacing for printing

Signed-off-by: Matthew Schick <mschick@redhat.com>
Update fitting diameter