This is something that has bugged me for quite some time but until just recently I put up with it.  I'm sure a lot of you have experienced dumping dust out of the hose when unhooking the hose from the dust collector.  IMO the hose end on the 27mm needs a slight modification by Festool to eliminate this issue but it's something you can make some improvement to after just a few minutes.  I got in the habit of putting the vac in manual and pulling the hose loose but keeping it near the vac suction and tapping it onto the ct to break the dust loose and let it get sucked into the vac. 

    You should be able to see from the pics below that the issue is with the 27mm hose end there is a pretty large recessed area that just attacts and retains the dust.  When you cut panels such as MDF (just one cut) this area will fill up and fall out of the hose once you disconnect it.  I just used some 5 minute west system expoxy to fill that gap and most of the problem is gone.  The 36mm hose does not have this recess so nothing mentionable collects on the 36mm hose connection.  There is still a dead zone created because the hose is so much small than the fitting and ideally this should be tapered from the small hose to the big outlet and no dust would collect.

    Just a simple quick mod to prevent some of this stuff from getting on the ground...     

 

Good question.  This modification will still allow the fitting to swivel.  If you ever take apart one of these fittings, you will see it is made up of three parts;  a retaining ring, an inner sleeve and the adapter -- as shown in the photo below.  The recess that is being filled in this modification is within the adapter and filling that recess will not glue it to these other parts.  



Note:  this photo is of the larger D36 hose and fitting, but the parts are similar other than size and, of course, the recess in the smaller D27 adapter that is the topic of this thread.  Heh, heh.