Air assist pressure filter using pop bottle

So your K40 has a brand new air assist and its supplied from a noisy piston type air pump. The air flow is pulsed and vibrates the lens and makes a noise.

This simple device filters those pulses out to smooth the airflow. Pulsed air may be better than smooth airflow, some pulsing may help clear the cut line? The bottle may also reduce condensation of water on the lens when your air is very humid.

It works by directing the air into a large closed volume, in this case a 2l pop bottle. The pressure pulses go into the bottle where they're absorbed into the large volume. Another port lets the air out at a constant pressure, hardly any pressure variation.

Want some puffing, use a smaller bottle.

The thing here is simply a bottle top with two 7mm diameter barbed couplings for the flexible hose between the pump and the laser. There are two versions, the first has slightly longer threads because it has a flat inner surface designed for a cork (or similar) gasket to seal tightly. You don't really need this for your laser because the static pressure is low and a bit of air leaking isn't important.

The second version has a small conical sealing ring where the top of the bottle is supposed to seal, it's also not as deep since it doesn't need a gasket. It seals reasonably well but not nearly as well as a proper bottle top. The barbs are more barb-like and the internal spigot also has a small ring to help retain a soft flexible tube.

It could also be used in a different way to filter dirty air, attach a pipe to the inside tube long enough that the end is submerged and it will bubble through the water in the bottle before it goes out the other air port.

Its easy enough to make this device with some hotmelt and a pop bottle to but it will be slightly more tricky to get it to fit because a pop bottle lid is so small. Use a larger mouth bottle if you want to do this, a mason jar for example.

Place this filter near the laser so that the pipe's frictional resistance to airflow helps filter the pulses from the pump, this is basically a first order low pass filter, to those who understand electronics it will make perfect sense.

3D printed parts are NOT as air/watertight as you may think, if you want it to be completely air or watertight the you should paint it with nail varnish to seal the porous 3D printed material.

Print with the thread side up, as shown in the picture, and use supports only touching the bed, don't want to fill the internal plumbing with support material!

It leaks air because printed parts are porous

Update 2023-05-23: On request, added a version where the ports are 10mm diameter. The barb is still 0.8mm more (on the radius)

Print Settings

Printer Brand:

Creality

Printer: 

Ender 3

Rafts:

No

Supports: 

Yes

Resolution:

0.2

Infill: 

20

Filament: Amz PLA Blue

Notes:

Supports in contact with the bed only.

Print with the barbed connectors down, cap open end facing up

Category: DIY