This gun as completely change my sandblasting performance. Inspired by thingiverse, I create mine in SolidWorks so I’ll can provide you multiple version (different hose Ø, sand nozzle Ø…) if you need.

I highly recommended pairing it with a metering valve that will allow you to control the air volume in the venturi effect; and a floor pedal of course. You will get a smooth mix of air/sand that will never clog in the gun again.

The air jet nozzle is straight at the sand outlet, which generates a much greater venturi effect. I sandblast a lot with it and the sand doesn’t damage the air jet nozzle so it’s fine.

You can use the metal nut from the Chinese gun.

I use 5 wall and 30% gyroid infill to be sure but there isn' any real “pressure” in the gun like trigger gun, there is just high speed air inside so I think you can reduce thickness

Specifications :

Air connection : ¼ NPT just thread 

Ø Pink sand nozzle Ø16,3 mm (standard Chinese nozzle)

Sand hose :Ø 15,5 mm

Video demo :

Setup : 1x 1,5 hp 50L compressor coupled to 1x 3,5cv 50L comp equivalent to 400 l/min airflow at 7 bars
Pressure 4-5 bars
6 mm pink nozzle on the gun
metering valve at 1/2 opening

The more powerful the compressor (air flow), the larger the sand and air jet nozzle you can use, and the faster (and larger) you can sandblast.
I precise that my compressors run almost non stop (not really recommended) but it's fine