Rotrics DexArm Enclosure exhaust pipe coupling

The Rotrics DexArm / Hexbot robot arm combines with an optional safety enclosure box for laser engraving, with a built-in fan. However, there is no obvious way to attach a pipe or tube to guide the fumes outside. I designed a coupling that makes it easy to connect a flexible tube of 125mm diameter to the enclosure's exhaust opening. The outer diameter of the coupling is 117mm, but the Blender file is included if you want to change that.

The screw holes in the coupling are aligned with the fan's screw holes, so you can use the existing screws to mount both together. The end of the coupling is slightly tapered to make it easier to slide a tube over. Some manner of thin sealant behind the plate is recommendable, I used strips of EVA foam sheets that are available in hobby stores.

Nozzle size used: 0.6mm
Material used: PLA
Print temperature 210 Celcius
Print speed 50 mm/s
Layer height 0.2
Line width 0.58
Initial layer line width 120%
Infill 30%
Brim of at least 8mm is highly recommended
Heated build plate is recommended but not required. Some warping will be undone once mounted.
User-specified seam position to neatly align the seam
2 top surface skin layers
Concentric top surface pattern if you want circles around the screwholes

If you actually 3d-print this with a DexArm / Hexbot, mind that you need to raise your build plate to print within a few cm of the arm's home position, otherwise the arm will not be able to cover the entire area. In addition, set the Work Origin at 21cm in front of the arm's base: The further the arm has to reach, the less accurate it becomes.