I have posted an article about silent home-made airbrush compressor before. It was a free translation of article I have found at one of the resources from eastern Europe I use. Then I decided to build (diy air compressor) myself and since I have found few tips to make this compressor more comfortable to use with less maintenance effort.
Here is the schema:
As you noticed this does not include the electric drawing as it is exactly the same as in my earlier post. On top of that I’ve added a pressure switch which needs its own power cord.
So how does it work?
The air from fridge compressor is pumped to receiver (tank). To keep the air clean I’ve used air filter (petrol filter) on the input of the compressor.
Tank (receiver) works as capacitor (collecting the air) and we can use any empty gas tank or fire extinguisher that can hold the pressure around 100 psi. Some people are using 2L or 5L plastic bottles which I wouldn’t recommend as it can’t hold that pressure. Here is the tank I have used.
When we consider the pressure in the tank, the air is as well pressing in reverse on compressor with that pressure and this can cause the compressor to overheat or even destroy it after some time. So I recommend to use check valve (non-return/one-way valve) between compressor and receiver.
Check valve allows air to flow only one way.
Do not forget what I mentioned in my earlier article about compressor that fridge compressor use to spit some oil on its output, and I’ve recommended to use transparent tank that you could see all the spat oil in it and from time to time empty it. Here we go further by using oil-humidity collector-reducer (professionally called Air Filter / Regulator / gauge - Ampro AR2654 3/8-Inch Air Filter, Regulator) before the check valve, that means there will be no need to empty the receiver :).
Very useful part is a manometer on your tank. You can watch the pressure inside while configuring the air pressure switch.
Automatic Pressure switch
A really scary word for someone who builds his own compressor. Don’t worry there is nothing scary about it. Setting it up is also very easy.
Simple explanation of its function:
It will switch compressor off when we get maximum pressure in the tank and then switch it back on when pressure gets down to the minimum level. On the schema it is connected between tank and check valve because we have to set it up according to pressure from the tank. Technology is very simple and genius at the same time. The compressor is connected to electricity through this switch. When there is no pressure the circuit is closed and compressor is switched on pumping the air into tank. But when pressure is raising up pressure switch gets to a certain point when the pressure gets to the maximum and the circuit and compressor goes off. While we’re working the tank is loosing the air and at one moment the pressure is too low to keep the circuit of pressure switch opened so compressor will go back on again; so your compressor works less with better efficiency and it won’t overheat and hopefully will live longer.
The pressure switch is very useful thing because it saves not only our compressor but reduces our electricity bills as well (Air Pressure Switch for Single-Stage and Dual-Stage Air Compressor – 1/4in).
How to set-up the pressure switch?
This switch has two threads under the hood. All you have to do is to set the position of screw females to set the maximum and minimum level of the pressure. First turn on the compressor and notice the pressure on manometer when it goes off; after that, loose some air to notice the pressure when it goes back on. Now pick one of the threads and screw the female screw halfway in. Turn it on and watch the pressure again for both positions.
What we have to find that is which particular thread is responsible for switching it on / off.
Update: just added more detailed instruction on “How to Set Up The Air Pressure Switch“
That is all from theory. Let’s do some manual work. I won’t write about building process, you can read it here because it is similar except for few things that are not really important. All depends on your skills.
Here is some of the stuff I have used.
As case I’ve used an old speaker box.
And some pictures of final product “Silent almost maintenance free airbrush compressor”. I hope that not only airbrushists will enjoy this post…
I didn’t even finish the case. I wanted to put a grill or net on both sides to keep it practically opened for good air flow. For now the cooling is fine as it is still opened :). It is working fine and the most important thing – it makes noise like fridge (almost unnoticeable).
When I come across something better be sure I’ll post it here.
made by Ing. Alexander Voronko, PhD.