Getting More Air

[Mike]

Just some feedback for those who might go down the same route of trying to get more air on the cheap.

I have installed a second Chinese air pump, the flow rate is meant to be twice as much as the one that came with the machine, same make.
The way I have set it up is to run both compressors on parallel or just one at a time, so I should be getting a good blasting at the cone, except I am not.

The air flow out the air tube at the bulk head fitting on the back of the machine is very good but by the time it gets to the laser head cone it’s lost a huge percentage of its flow, reason for this is that the tube which runs from the bulk head to the laser head is very thin causing large losses and the supplied compressors don’t have allot of pressure behind them to push all the air through this tube.

I have already changed all the air tubing form 6mm to 8mm on the outside of the laser cutter, which helped a little, and plan to change the thin tubing inside tonight to more substantial tubing, it has to be flexible though so I have got some silicone tube.

I suspect that if I had just changed the tube to start with, i.e. reducing the losses in the pipe, I would have got better performance without needing to buy a new compressor.

[Spooky]

Velocity / Pressure / Volume,

It's a combination of the three Mike, as yet i haven't found a way of achieving it under £400, tubes of reducing diameter increse velocity but reduce pressure, what we are looking for is increased velocity and increased pressure, to get that you need big displacment to get high free air delivery figures. Compressors of all types rate as Displacement, Free Air Delivery is what actually matters @ any given pressure. To get decent (read:worthwhile) improvement you need 4 Ltr Min Free Air delivery at 25 Psi. No compressor under £400 will achieve that. (unless you use a direct drive type that sounds like the orchestra of hell playing in your workshop )(95DBa +) Direct drives are also not rated for continious use, using one to power a laser all day will burn it out in a few weeks. Belt drive is the way to go if you can stand 75DBa or SHHH / dental if you can stand the prices.

best wishes

Dave

[Mike]

Hi Dave, yes I know , trying to do things on the cheap often ends up costing (me) more.
There is enough improvement with what I have done and I would say it was worthwhile, but I am not doing all the cutting work that some guys here do.

When I get a new bigger machine I will definitely look at getting a better compressor

Cheers

Mike