Plywood is burning edges

Ok so hopefully I can make this simple:

  • Material: 3mm Plywood (Bunnings) Yes I am aware this has glue throughout and is not good quality but I do not have issues with large pieces only these 40mm circles)

  • Cutting multiple circles

  • Historically 3 cuts standard to cut through

  • 200 speed

  • 100mx power

  • Zoffset 1.00

Lately it does not seem to want to cut through in 3 cuts, so I have added an additional cut but it it now seems to be burning the edges at 4 cuts.

If more screenshots required of settings happy to do so.

Hopefully someone in this forum starts typing frantically as they have the magical answer !
Any suggestions welcome :slight_smile:
Thank you

@LunaRose Welcome to our forum…according to the laser Manufacturer your laser is the equivalent of 15-20 watts in CO2 .

You should be able to cut up to 6mm with no problem.
The burn might be cause as a result of 100% power. Have you played with a lower power ?



Thank you so much for your reply.

Yes I have an Emblaser Core and it is a great machine and has in the past cut perfectly with those settings.

I will try to reduce the power but historically if I have done that it was to create a lighter burn.


Do you have air assist? If not, I’d suggest looking into it, if you plan on cutting a lot with your laser. Otherwise you can try slowing down a bit. Also make sure your focus hasn’t changed on the laser.

Hi Blake,

Thank you for your tips.

I do have air assist which ahs been on the machine from day one but it stopped working so whilst waiting for a new one to arrive from the company I purchased it from I used the machine and it worked better without it.

I will try to slow the burns down and check the focus once again and see how I go.

Thank you for your help.

Hmm. Air assist is pretty much a requirement for cutting wood. Most folks seem to find that the more air you can blow into the cut the faster and cleaner it goes.

Also, one of the purposes of air assist is to keep soot and resin from being deposited on the lens. If you’ve been running without air assist there’s a good chance that your lens is filthy which will really kill performance.

Yeah, I run upwards of 40PSI when I’m cutting wood for sure. It keeps soot out of the cut as well, which will sap power from the beam.

Thanks to all who have helped out tried all of the suggestions and to be honest I do not know which one worked but it seems to be cutting as it did when I first bought it.

Thank you to all :slight_smile:

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@LunaRose. Happy to hear it’s working for you. :grinning: :+1:

Blake - do you have any idea what the flow rate is through the nozzle?

40PSI… Unless you mean something else?

40PSI is the pressure in the line, but it’ll come out faster through a nozzle than through a pinhole - the amount of air moving is usually measured in CFM (cubic feet per minute) or LPM (litres per minute). I have no idea what mine uses either (I run 40 PSI and my 5510A keeps up with no problem).

Is that something I can run some math calculations on, with nozzle diameter or something? It’s a solid 40 out of my regulators, but we’re running a pretty huge air pump for our whole shop.

I don’t know, honestly - You could probably figure it out based on the capacity of the tank, and how long it takes to empty at a given pressure setting, but I dunno.

Well there’s at least a dozen connections all being used, so probably not doing that.

@Blake - a simple way to measure flow rate is to install an inexpensive rotameter in the air line leading to the nozzle. I put this one on mine, with a 10-100 cfh range:

1 cfh = ~ 400 mL/min

I get about 55 cfh with the Thunder Laser’s diaphragm pump, which seems reasonably high to me. The smaller California Air Tools compressor put out about 2cfm, so about 120 cfh or twice what my diaphragm pump puts out. I may try out the CAT compressor at some point.

Dwyer makes some much cheaper rotameters but those intended more for just verifying some sort of flow exists as opposed to providing a reasonably accurate measure of flow rate.

On edit: If you get a rotameter, buy one without a valve at the inlet - those can restrict the flow rate quite a bit.

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Yes, but the CAT 2cfm is probably at 90 or 40 PSI. The diaphragm pump is probably a free air rating with little or no back pressure. That CAT is moving a lot more than twice as much air as the diaphragm pump.

You may be right about the CAT cfm being at 40 or 90psi (Googled definitions vary on if this is based on compressor input or output) but I actually measured the cfm of the TL air pump with a flow meter that was probably at something a little over atmospheric pressure so that number is somewhat known. At some point I will probably measure flow rates from both under more defined conditions. Maybe I’ve watched too many of Russ’s videos .

Absolutely. I use plenty of air blowing through the cut. Nice and crisp. Brown and not black…

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