HackSpace magazine

Portable desktop air compressor

By Jo Hinchliffe. Posted

Air compressors are incredibly useful, but are often large, noisy tools that can take up a lot of room in a workshop, or require a lot of plumbing and airlines to site them far away but still be useful. The benefits of larger compressors are that they can create more pressure and can throughput a larger volume of compressed air, meaning they can power all manner of tools and systems. However, for certain tasks, like scale model airbrushing, or for an air supply for an air assist on a laser cutter, larger volumes of air aren’t particularly needed, and the noise of a larger compressor might be avoided.

In the last few years, tiny desktop air compressors have been available and affordable online, with budget ones sold as 1/5 hp or 1/6 hp compressors. They have a tiny tank and claim to be very quiet in operation. We bought ours for £52 from a generic online platform, and it arrived after a few weeks. Interestingly, ours was advertised as a 1/6 hp model but, when it arrived, the box and the instructions claimed it to be 1/5 hp.

We would hazard a guess that a lot of the budget 1/5 or 1/6 hp compressors sold are all the same, regardless of name, and that the motor ratings may not be totally accurate. Whatever the actual rating, it’s an important note that these compressors supply enough volume of compressed air for airbrushing, but you could never run any larger air tools off this. You aren’t going to be using an air-driven impact wrench with this kit.

Whilst we giggled at the packaging as it states ‘Bottom noise’ on it as a feature, it arrived well-packed and with a UK plug. Our version was supplied with a relatively useful instruction manual.

At first glance it wasn’t too obvious how to adjust the pressure and output of the machine – the adjustment knob has to be lifted before it can be turned. It’s a pleasant surprise how well this compressor is built. The only plastic parts are the adjustment knob and the pressure switch housing, and it all feels solidly put-together. The footprint of the compressor is tiny at around 26 cm by 15 cm, and it truly is a desktop machine.

Whilst we did giggle at the text on the packaging, the unit is very quiet in operation

 The compressor is capable of pressurising up to 4 bar and, adjusted to reach this maximum, it will cut out and will power up again once the pressure drops to around 3 bar. Adjusting the output enables you to keep the machine at lower pressures, and it seems to be a similar percentage drop in pressure before the compressor kicks back in to recharge. In use, the pressure switch works well, and the compressor consistently kicks in to maintain the set pressure.

As it has only a tiny tank, it does kick in regularly: you won’t get more than a few seconds of supplying any volume of air before it kicks in again. In practice, though, this doesn’t really matter as it is very quiet in operation. Certainly, you can work right next to it for a long period without ear protection. If you were using it as an air assist for a laser cutter, it would probably run continuously but, again, we don’t think this would add much noise and probably less than the laser cutter extraction system would generate.

It has a ¼” BSP connector which is a common size, meaning that many airbrush kits will be directly compatible and there are adapters available for 1/8” BSP, for those airbrush kits that require them. Searching online, there are ¼” BSP to hose connectors available to connect to a small pipe for a laser cutter air assist mechanism. It’s recommended, with most compressors, to use some PTFE tape on threaded connectors to stop small leaks, but we found our airbrush hose worked fine without any.

All set up with a budget airbrush; this compressor can help create a reasonable budget setup

 It also has a moisture trap which is useful if using this for airbrush painting. This stops any accumulated moisture from travelling down the air line, which would cause problems with paint finishes. The compressor is oilless (unlike its larger contemporaries), so we have found that for airbrush work it’s a very clean air supply. Being tiny, it’s also very light, at around 3.5 kg, and has a pretty robust carrying handle which can be folded out of the way. After trying airbrushing with a larger compressor, it’s certainly much easier to be able to site the compressor and air lines in places, making it easy to work with.

The only small issue we have found with the compressor is that it sits on rubber sucker-type feet, and these were variable on different surfaces in terms of how well they stuck down or held the compressor in place. On a kitchen worktop-type surface, we found the compressor could slowly travel with the vibration. This is easily rectified with a small clamp, or other ways to keep it in place. Overall, we are finding this a really useful little compressor for our airbrushing experiments.  

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