Two big laser questions

[Josh Brower]

I have a kern laser than initially cut through 1/4 inch wood like butter, but doesn't seem to make it any more. I've used it for about 30 hours since I got it with no adjustments, and kern thinks I need to make adjustments now to make it cut correctly again. It doesn't make sense to me? Any ideas?

Second...how big a laser do you need to cut 5/8 solid wood (anyone have one), and is it worth trying since the kerf may warp with the depth of cut?

Is this a cnc router only project?

[greg lindsey]

How big a laser you got, I'm using 100 watt synrad, nossle injected air/co2 lasers and I don't get through 1/4" board easily, several passes are required.

[Rodne Gold]

The laser can go out of alignment for various reasons , even a hard bump can mess with it.
In all likelyhood , transport , unpacking, mirror/lens cleaning etc has caused a mirror or lens holder to shift or has loosened one of the set screws.
Cutting thick wood is not a good application for a laser - you will not only have charring problems , but the fact is the cutting beam is not a "straight line" , its shaped like an hourglass and the thicker you go with the material , the worse it becomes trying to cut - there is only a certain portion of the beam above and below the focus point where it has enough power per area to actually cut. You would need a powerful laser (250w) and a 4 or 6" focal length lens to cut thick stuff and even then it wont get great results.

[Dan Hintz]

I'm using 100 watt synrad, nossle injected air/co2 lasers and I don't get through 1/4" board easily, several passes are required.

Sheesh, what kind of hard wood are you trying to cut that a 100W won't slice 1/4"?!

[Frank Corker]

This might be caused by having the ppi too high, which can cause severe burning, however unless you are doing something like lignum vitae it should be able to go through it.

[Mike Null]

Kern is a respected brand in use in many commercial settings. I would be inclined to follow their advice to at least see if it helps.

[greg lindsey]

Sheesh, what kind of hard wood are you trying to cut that a 100W won't slice 1/4"?!

Dan, I read board but was thinking plywood, happens when you stay up to late. 1/4" solid isn't too bad, but plywood is a bugger. LOL Thanks for the correction.

[Chris DeGerolamo]

Dan, I read board but was thinking plywood, happens when you stay up to late. 1/4" solid isn't too bad, but plywood is a bugger. LOL Thanks for the correction.

I am able to cut 1/4" Baltic Birch plywood in a single pass with a 30W Epilog...are you doing multiple passes with 100W on 1/4" ply?

[greg lindsey]

I am able to cut 1/4" Baltic Birch plywood in a single pass with a 30W Epilog...are you doing multiple passes with 100W on 1/4" ply?

I am not really into wood cutting, my mainstay is plastics and textiles, but I get requests for cutting plywood now and then and it's probably stuff from HD that the customer brings in. Just seems like it's the lamination that gives me trouble, don't know if it's the wood or glues used, but if you guys are getting through plywood with 30 watts, maybe I need to recheck my alighnments.

[Dan Hintz]

Just seems like it's the lamination that gives me trouble, don't know if it's the wood or glues used, but if you guys are getting through plywood with 30 watts, maybe I need to recheck my alighnments.

The glues are the biggest problems with plywoods, but you should still be able to bang through the bad stuff with that much power.

[Mike Null]

When cutting wood maintenance is an important issue. Be sure your lens and mirrors are clean and your exhaust is working well. Bearings and tracks need cleaning frequently as well.

I am skeptical of anybody who says they can cut 1/2" or thicker wood cleanly with a laser--even with a 100 watts or more.

A cnc router will probably do a better job faster.

[Michael Kowalczyk]

Dan, I read board but was thinking plywood, happens when you stay up to late. 1/4" solid isn't too bad, but plywood is a bugger. LOL Thanks for the correction.

If it is exterior glue it will be MUCH harder to cut than interior glue. Check with your supplier to see which one they carry and get interior glue only next time.

Josh,
Depending on the size of the part(s), the complexity of the design and the quantity needed may help determine to CNC or not.

[James Stokes]

I have cut 3/4 white oak with my 100 watt and am unable to cut 1/4 Ebony. Depends on the woods.

I have a new tube coming that is supposed to test out at 140 watts. I will see how it cuts when I get it installed.

[Josh Brower]

I know Kern is a great brand. I have a friend with a huge bed. I cut 1/4" solids like maple and cherry (no plywood) easily at first. I'm thinking something simple is wrong, so those are the suggestions I'm looking for.

Thanks for all your comments!

Josh

[greg lindsey]

Josh, sorry if I hijacked your thread. I think I got us off subect here a little.

Did you ever say what wattage you were cutting with or age of machine, I don't remember seeing anything in your tag line. I would inspect the lens, mirrors and alignment. When my epilog is not acting correctly, it is most often the alignment. Mine gets alot of use and I bang it every now and then, knock if out of alignment.