Flux syringe cap

This is a flux syringe cap.
It's interior cavity is slightly conical, so it'll snugly fit a classic "Amtech RMA-223 (clone)" flux tube.
As it's an OpenSCAD, it can be easily modified to fit another kind of dispenser.
The 4 main parameters to change would be:
ID1 and ID2 relative to H1: These are two diameters to be measured at a distance of H1 on the collar of the dispenser (see pictures).
IntLen : This is the length between the ID1 measuring point on the collar and the tip of the dispensing needle (add some leeway here).

You can also change the wall width (WW) but don't go too far...

The plunger used in the pictures is from Divinecobra: http://www.thingiverse.com/thing:1902471