Acknowledgements: This is very important! This OpenSCAD design was heavily based on the design by Nunu57 (see box on the left) and I freely and gratefully acknowledge the work he put into creating his design. The only reasons for modifying this were (a) I had trouble with the air inlet nozzle, which kept breaking when I tried to clear the supports, and (b) I wished to experiment with things like putting a metal insert into the nozzle orifice - making my own source meant that I could change things as I see fit.
If all you want is an air assist nozzle, and have no wish to modify things, then Nunu57's design is absolutely fit for purpose.
Design options: There are two forms of nozzle - curved and straight vanes. The curved vane version can only properly fit in one position to match the vanes on the laser unit's heat-sink, so it comes with two choices of inlet pipe position - to the left as you face the laser, or to the right. This option gives the absolute minimum resistance to air flow from the the laser's built-in cooling fan. You will have to modify the code if you want the inlet pipe to come in from any other direction.
The other choice is the straight vane version - this can have the inlet in any position, at the cost of a little extra resistance to air flow from the laser unit's fan (but not a lot).
None of my versions include an air inlet pipe: I have designed it so that a 4mm o.d. metal pipe can be glued into the air inlet hole, which gives a robust connection that isn't dependent on the skills of the 3d creator to produce. I bought some brass 4mm o.d. tube off eBay for quite a small amount of cash (some suppliers will sell a 50mm sample for little more than the cost of the postage, which is enough for this piece).
You will also need an o-ring for the recess, which will make a seal for the pressurised air. These can be found on eBay, 16mm outer diameter, 11mm inner diameter and 2.5mm section. Try to select the softest available - mine are a silicone material.
Please refer to Nunu57's description for all the other important details, such as details of the air hose. He also has designed some very good air hose clips to match.(https://www.thingiverse.com/thing:5186927).
David_J
