The hotend was quite loose in my titan extruder clone.
I figured it was due to the bad fit and strength of the cover.
So i created a stronger cover which really locks the hotend in place when the screws are tightened.
I've printed with this for quite some time now and the print quality is a lot better than with the original cover.
Update 2019-09-03: Eventually the hotend became loose again.
Furthermore, i also noticed that the gear was slightly tilted up.
So I created a version 2 of this to fix those issues.
It has a stronger grip on the hotend and additionally you can use a short 3mm screw to tighten the hotend if necessary (haven't tested that yet since for now the fit is perfect and the hotend does not move).
Note: the screws to attach the cover need to be around 30-35mm long - additionally one longer screw (>= 40mm) is required to not tighten the gear too much - however this screw can also be omitted if not available.
The screw holes are closed with one layer intentionally to allow printing without support. Just use a 3mm drill to open them after printing.