LaserUser.com Forum (formerly RDWorksLab)

Hello all - I'm about to upgrade the air assist on my laser and wanted to see what the minimum compressor tank size should be. Right now I'm leaning towards the little vertical 8 gallon "Super-Quiet" NorthStar oil free compressor from Northern Tool. Or perhaps the California Air Tools 8 gallon horizontal aluminum tank on Amazon.

Are these tanks suitable enough in size to power the laser during cutting operations?

Beyond the needs for the laser, I don't run a lot of air-powered tools. My current and only compressor (for my shop) is a 1 gallon Senco PC1010.

Tank size will determine how frequently the compressor cycles/runs.
The CFM rating of the compressor will determine if the compressor can keep up with your use.
5psi supply to you laser head will typically result is 2.5-4 SCFM use of air.
The compressor you listed will generate 4 cfm according to the specs - You could probably run for 1-2 hours before you lost pressure below 5psi at the laser - your compressor would probably run continuously though.

Thank you Pete. Can you elaborate on your "5psi supply will result in 2.5-4 SCFM use of air" comment?

The NorthStar description says it will deliver 4 CFM @ 90 PSI and 5.4 CFM @ 40 PSI. The CFM rating increases as PSI decreases. I'm confused on how only 5 PSI of airflow will max out the compressor's output. They only have a 70% duty cycle for these 'quiet' motors on this style compressor, so running continuously won't be ideal.

Do you have a recommendation for a suitable compressor or pump?

I have been using the Calif Air 4710 [4.7 gal, 1 hp] for a year and have flow gauge as my hearing is impaired, and it works a treat, quiet and enough air to blow off debris when needed .

LOL . What a rookie error. You are correct. I failed to account to the change in capacity with a lower line pressure. I locked in on a 4 cm flow rate and did not pay attention to 90psi.

The flow through an oriface at 5 psi with a pressure drop to 1psi assuming an oriface size approx 0.2 will be about 3.5 -4 scfm

Hi .... I have the 10 gal. California Air Compressor .... it keeps up at 40 psi continuously .... a great quiet compressor.

Brian