Cutting MDF

[Chuck Kahler]

Good morning gentlemen,
I need to cut some 3/4 inch thick MDF on my 180 W CO2 laser.


Anybody have any suggestions on doing this, Like Lens focal length and air assistpressure Setting.


Thanks for any input,
Chuck

[Kev Williams]

I've successfully cut thru 7/8" thick Cherry and 3/4" oak in one pass with my 80watt Triumph- VERY slow, but it did it. And I did it with a 2" lens. I tried the same cut using a 3" lens and it didn't even make it 2/3 the way thru the wood. (the unfinished cuts in the pic)
Seems the general consensus is the longer usable beam-focus distance that a longer 3" (for example) lens provides means you'll have better luck cutting thru thick items. My tests show otherwise -- my opinion is that the cut-kerf itself keeps the beam focus in check throughout the cut simply because the beam has nowhere else to go! My tests are evidence that a 3" lens's focal point power density is MUCH less than the power of a 2" lens. Any other settings, I don't do enough cutting to have much experience, but I will recommend cutting with a 2" lens, you should do fine!

cuts.jpg

[Chuck Kahler]

Thank you, that’s some pretty impressive cutting.

With your 80 W laser, what speed were you cutting the three-quarter inch cherry?

[John Lifer]

Real solid wood is easier to cut than MDF. Even with 180 watts, I think 3/4" is a stretch and Dang the smoke and charred edges will be ugly. Use a saw.
(my 80 watt won't cut 1/2" MDF btw)

[Chuck Kahler]

I went ahead and set up my 3 inch focal length lens and with the power set at 150 W and the speed set at 15 in./min. I was able to get a very nice cut on three-quarter inch MDF. There was some smoke, not A lot.


There was very little charing.


See attached photos s


As was suggested I am going to set up my 2 inch lens and see how well that cuts.


ChuckE783FA8D-36BD-402D-AD75-919D7439A4F8.jpg

[Chuck Kahler]

Which speed were you cutting the 7/8 cherry and the 3/4 oak?

Thanks,
Chuck

[Kev Williams]

SLOOOOWW, like 2mm/sec which is what, 4-3/4" inch per minute... Even slower wouldn't get thru with the 3" lens.

I would think you could go faster than your 15" per minute with a 2" lens-? However, a180 watt tube is going to have a different focused beam profile than an 80 watt tube, which may play better with a 3" lens than a 2"...

The fun of trial and error!