Bowden Tube Lock (revised)

This is a slight remix of my own [PC4-M10 Bowden tube lock](https://www.thingiverse.com/thing:4566395). I realised that with better accuracy of the printer (have a new CR-10V2 now) I had to reduce the tollerance/gap between inner and outher thread so that the tube will still be locked well when the cap is fully screwed on. The old version was simply to loose now.

I have these connector locks in use now for several months and I'm very happy with them.The PTFE tube does not move anymore and the connector doesn't loosen over time, even with heavy retracts during print (which used to loosen the connector ring after a while).

I use the long version for the extruder end to maximize the grip on the tube. I also extended the base half a millimeter so that the base really touches the extruder and can not be "pulled" during retracts.(Distance between bottom and connector ring is now 10mm, if you have shorter connectors, lower the print in Cura to cut of a millimeter or so from the bottom o