Mdf

[Bruce Dorworth]

I have been cutting/engraving a lot of MDF on the laser. I use 1/8" and 1/4" material. In the past when I cut or engraved the MDF it had a nice light brown edge and the engraving were a light brown. Now the edges and engravings are almost charred. Even if I slow thing down. Has anyone else noticed with the MDF purchased at Home depot?

Thanks,
Bruce

[Mike Lassiter]

Check your lens. I had this happen this week. Found bottom lens cracked when I checked it to see if it needed cleaning. When trying to cut heard a hissing sound that hadn't heard before and lots of smoke and flaming unlike normal. Looking at lens it has a star burst crack in it. $234 for single lens from ULS......

[Glen Monaghan]

I haven't had to replace any lenses on my machine yet, and haven't tried alternatives, but maybe it would be worth trying one of those $30-60 ebay imports? Anybody care to share their personal experience with both US OEM and import lenses?

[Rich Harman]

The 1/4 inch MDF that I get from HD cuts with a dark edge, the 1/8 inch cuts with a light brown edge.

[Larry Bratton]

Pricey..bought a new 2" from Epilog a few weeks ago and it was $108.16

Check your lens. I had this happen this week. Found bottom lens cracked when I checked it to see if it needed cleaning. When trying to cut heard a hissing sound that hadn't heard before and lots of smoke and flaming unlike normal. Looking at lens it has a star burst crack in it. $234 for single lens from ULS......

[Dave Sheldrake]

Make sure it's Medite or Premium MDF Bruce, the exterior stuff contains quite a lot of formaldehyde and won't do your lungs a lot of good. Medite uses water based resins and cuts with a light to medium brown edge, exterior stuff cuts with a dark to charred edge (and tends to spatter when your cutting it) Sheet colour isn't always a good guide but in general the best laser MDF is quite a light colour and smokes far less when cut.
Some suppliers mix it up on occasion and you end up getting delivery of the non laser stuff (I've had a few), horrible to cut, uses more power and looks aweful.

cheers

Dave

p: 1/4 inch stuff takes a LOT more heat to cut hence it's not unusual to get a blackened edge.

[Kev Williams]

Easy enough to tell if it's the lens, provided you have some scraps of the old stuff, just cut some of it--

If the old still cuts like it used to, then you can assume the problem is a different glue or additive in the new wood.

If the old cuts like the new, then look at the lens and/or mirrors...

[Lee DeRaud]

The 1/4 inch MDF that I get from HD cuts with a dark edge, the 1/8 inch cuts with a light brown edge.

Yup, same here, although with my 25W machine it tends to char more than for people with more wattage. Awhile back (2-3 years), I got a couple of batches from them of what I assume was exterior-grade stuff, which I found almost impossible to cut. But at this point, I think they only sell the lighter grade here in southern California due to emission standards, and it wouldn't surprise me if they simply use the same supplier nationwide.

For what it's worth, at the same time they went to the current stuff, they changed the labeling to reflect that it's actually 3mm and 6mm. Still marked in inches, mind you, but 0.236" and 0.118" rather than 1/4" and 1/8".

[Kevin Groenke]

I haven't had to replace any lenses on my machine yet, and haven't tried alternatives, but maybe it would be worth trying one of those $30-60 ebay imports? Anybody care to share their personal experience with both US OEM and import lenses?

In an academic environment with 4 lasers and ~1000 users, we tend to burn up some lenses (though tying together switching for exhaust, air assist and laser power has helped tremendously).

Over the years we've used OEM and domestic replacements from ULS and Laser Research Optics ($165 unmounted). The last ones I got were Chinese lenses from the auction site ($35 unmounted - seller=laserlands). The only considerable difference I have noticed between the ULS OEM lenses, the LRO replacements and the imports is that the actual focal lengths on the Chinese lenses seems to be inconsistent so the focus tool needs to be adjusted to compensate and needs to stay with the lens. Longevity of the lenses and spot size seems to be pretty consistent across the board. I put in the first $35 Chinese lens in February of this year and it still going strong.

$35 vs $230 is a no-brainer if there is not significant difference in functionality.

Oh, 1/16" mdf cuts great but it's tough to find, 1/8" cuts pretty well with light toasting whether on our 60W, 120W or 150W machines, 1/4" cuts OK on the 150W - single pass with dark toasting on the 120W - two passes with dark toast on the 60W machine. Very slow to cut 1/4" with anything but the 150W laser, so we prohibit it. Our vendor stocks Flakeboard brand 1/8" and 1/4" MDF. They special order the 1/16" for us which is Plum Creek Glacier Green MDF.

-kg

[Michael Kowalczyk]

I have been cutting/engraving a lot of MDF on the laser. I use 1/8" and 1/4" material. In the past when I cut or engraved the MDF it had a nice light brown edge and the engraving were a light brown. Now the edges and engravings are almost charred. Even if I slow thing down. Has anyone else noticed with the MDF purchased at Home depot?

Thanks,
Bruce

Bruce check the actual thickness. Sometimes that's enough to do it. And I would clean your lens every hour or so if you are doing a lot of engraving and or cutting MDF. It will corrode the interior over time from what I hear.

[Andrea Weissenseel]

this seams to be a world wide problem, I had this happen to me also - it didn't cut through and the edges were charred. It depended on the supplier where the MDF came from - here you can tell by the color of the material if it will work or not, if it is more brownish it's fine and if it's more like a yellow brown I leave it

Andrea

[Bruce Dorworth]

Thanks for the comments everyone. Yes, Andrea I did notice that the color of the MDF at Home Depot did change.

What is this Plum Creek MDF that I hear everyone talking about? Where do you get it, and how do you know it is PC MDF?

Bruce

[Jerome Stanek]

The plum creek that we use is .75 thick and is stamped plum creek on the side