Sparkfun 937B Soldering Station iron collet

For some reason, the collet on my Sparkfun variable temperature solder station is very loose, and sometimes it gets detached while soldering. I suspect the thread somehow got stripped.

Here is a 3d printable version, this part is located at the end of the heat barrier, so it shouldn't be as hot as the iron tip. Regardless, it's best to print this in high temperature filament.