[mekanofreak]

Hi,

I got a 50w 40x40 co2 laser from china a while ago (maybe 2 year) and upgrade it a bit, I added a true air assist (adjustable 5 to 35 psi), installed an ampmeter, a hood switch and water flow sensor, a water chiller (compressor type), adjusted the power supply output below 20ma (came adjuster at 22) and replaced the tube a few month ago because I had doubt about the power of the tube since some people with the same machine claimed to cut material I had trouble with and that solved all the problem I had.

The problem I am facing today is bugging me, I can cut thick acrylic (1/2 inch), 6mm plywood in single pass at 10mm/s 80% power ,and 12mm in 3 pass at the same setting, I tried cork and gasket maker sheet, engraved glass and wood, cut 10mm birch plank and never had a single problem ! But today I tried cutting 1/4 inch MDF and even at 5mm/s and 5 pass the laser just wont go trough ! At 6 pass the laser start to pierce in some spot but not enough to separate de piece from the sheet. I suspected the laser and I double chececked everything, mirror alignement is perfect, all mirror and the lense is clean. tried cutting birch plank and plywood and all is good so the laser is not dying, I tried upping the air assist pressure but that did not help. If i slow the laser to a crawl at 3mm/s at 90% it get trough after 4 to 5 pass but the part is so charred all around that it is unusable. I went to the store ( following all coronavirus precaution, gloves mask and all that) and got another sheet of mdf from another company, this one seem a bit lighter in color, same thickness, but that wont cut either and when it does its more burned than cut !

So I guess my question is, any of you got experience with cutting MDF ? Plenty of people here seem to cut it with k40 without problem and I just can't figure what I'm doing wrong ! Maybe some additive or the glue used in the MDF I got have are the culprit ? maybe some magic laser setting I never messed with ? I would really like to use MDF for some future project.

[Dean448]

Man made wood composites can be difficult to cut due to the glue. I’d buy samples of mdf from different sources to see what cuts. Slowing it down just creates a charred mess


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[mekanofreak]

Man made wood composites can be difficult to cut due to the glue. I’d buy samples of mdf from different sources to see what cuts. Slowing it down just creates a charred mess


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Yeah, I found some other sample at various hardware store that are still open in my area and not a single one of them seem to cut well. I will probably try again after the pandemic is over, because washing everything every time after I come back home is making my wife give me nasty look !

[robertlroberts]

I have cut MDF, but have found that it is not a good material to use with a laser. I have a 180W machine. The heat thatt is generated make MDF a poor material, backside burns badly.

[mekanofreak]

I found one type that would cut. but like robertlroberts said, it made a sticky burned mess on the backside, guess I'll use plywood instead. Thanks everyone !