The Velleman Vertex Delta 3d K8800 comes with a filament spool holder on its top, laying position, with direct filament injection. Not only is that destroying the extruder entrance very fast when using more abrasive filaments (Wood, metal), but it also messes up with the filament end detector that goes crazy, as it detects the filament by being pressed down, but the filament comes from up... So you'll end up with a lot of false positive, even with high precision filament.
I have many different filament brands and spools. For them I have built some airtight storage boxes. Working great but nothing to hold the tube on the printer! So I made this little extension, that clips on the printer itself, no need for holes on your babe. The tube fast plug is purposely a bit lower than what it should, forcing the filament to enter the extruder a few milimeters lower, ensuring the filament detector is always pressed when there's some filament
As the printer's top plate is not finished after but only cut, the width might be different, so make sur to measure it correctly and adjust the model accordingly before printing! Mine is 85.87mm. It is printed a bit longer so it fits.
It doesn't really matter, all you'll have to do is tapping the M5 for the tube plug.
PLA breaks easier than ABS. Choose wisely, as the piece clips on your printer. Normally, you'll almost never remove it though, so you might spare your health and use PLA
The hole printed is set at the correct 4.2mm diameter for M5 festo plugs. After the print is completed, you'll need to tap the thread
Tube fast plugs
You'll need a tube fast plug. The printer uses 1.75mm filament, so your tubes are most likely be 4x2mm. Buy some fast plugs like at festo per exemple.