Purchasing material

[cindy.burns]

I am a teacher and need alot of material to start I plan to get some proofgrade the kids may bring some of their own wood. How do I know what settings and is there some wood that cannot be used.

[bansai8creations]

I don’t have much experience with non PG woods (yet), but I use lots of other non PG materials…

For settings, start with the closest PG option to what it is (or you think it is), and then if it’s a softer or harder wood, adjust a bit, and then test (or at least don’t remove the board from the bed until you confirm it’s been cut through). E.g. cedar (soft) will not need as much power as walnut or oak (hard) for etching and cutting.

Risk of using non PG plywoods is you don’t know if the glues used will release any toxic chemicals–or any other treatment for the wood. And have a fire extinguisher or a spray bottle of water on hand in case you do get more than just smoke!

Also the density due to knots in the wood or type of adhesive and filler layers will always contribute to variations in the results, too, so even if etching on plywood looks great, the cutting may be affected…

Good luck!

[ben1]

You will want to use the search function in the upper right corner to learn how to test your materials and what to look for. This question has been answered many times. There are also many resources online as the GF is not the first 40-45 W CO2 laser on the market.

[marmak3261]

My go to cheap wood that I can get whenever is a 1/4" lauan from the big box hardware stores. Once side is usually in good shape. There are issues with voids and knots, but at $6.00 for 2x4’ sheet, it works great in a pinch. Just do some tests using the settings for thicker plywood. You can re dimension it with just a good utility knife and score deep on both sides.

Lots of other places to go, depending on where you live. Lots of posts about alternate wood sources.

[eflyguy]

Beyond the manual in 3… 2… 1…

You can’t allow them to just bring in any random material, because you will end up spending hours chasing down settings - assuming you can accurately identify what the material is! A lot of material looks similar, i.e. there are plastics that appear similar but some can damage the machine (and you!) while some are completely safe.

I suggest you get an idea of the things they would want to make, then find local sources of materials that are suitable for those that don’t want to pay for PG materials.

[PrintToLaser]

@cindy.burns

. How do I know what settings

Testing is the only sure way to dial in the settings. The proofgrade materials have a few advantages depending on what you are after. #1- they are safe. There is no sanding, staining or finishing and it is masked, so when you pull the mask you are done - except for assembly if there is any.

Like @eflyguy said, you need to use known safe materials so put restrictions on what the kids can bring in.
It won’t take you long with a heard of kids, to get an understanding of limitations - and soon you will be the coolest teacher going!

[brokendrum]

@cindy.burns

is there some wood that cannot be used

Not all woods are created equal, but most you find in places like Home Depot will be usable.

I have found this site to be handy for the ‘odd’ woods.
Explanation of some terms at the bottom of link.

Wood Allergies and Toxicity | The Wood Database

[evansd2]

@marmak3261

lauan from the big box hardware stores

My 1/8 meranti lauan chars so badly I hate to use it. Luckily I can get Baltic for a very low price so I just use that for almost everything.

[rbtdanforth]

@marmak3261

There are issues with voids and knots, but at $6.00 for 2x4’ sheet, it works great in a pinch

I have used that Lauan and like the look of the less than paper thin surface, however at $15 a 4x8 foot sheet that I cut into 5 - 19 x 48 inch sheets Revolution ply starts a 3/4 the price and gets another 25% more useful pieces. Still less than paper thin, and mostly only one side nice, but many fewer voids (Only where two big sheets go together there is a line) and it is barely more laser resistant than the base wood, and it is far more eco-friendly as they go out of their way to point out.

For other pieces of wood (make sure it is not pressure treated, as that makes it very bad) you can used this to check out the best settings…

Engrave and Cut 1/4" Mahogany tips?

This is the test I run on every new wood species and often on several to test what I want to actually use. but this first test runs the engraves at twice the number noted and then comes back and makes the cuts at the numbers noted and then cuts off the piece at two passes at 125 all full power. [evans%20tests] Watching closely while it is done allows me to put a wet cloth on after it cuts in the case where it starts to make charcoal,this is the Zebrawood piece after sanding it as the cut is de…

[caribis2]

I would look at this problem from a “what are they going to do?” perspective.

If they are going to cut out stuff, I would approach it as:

1. Set a max material thickness. You really don’t want someone doing nine passes on a 3/4" piece of wood.
2. Non-resinous domestic hardwoods. There are exceptions to this rule, but do you really want to deal with them?
3. Plywood has to be true Baltic Birch or an mdf core. Remember, there will be part of a cut that doesn’t go all the way through. How old are your students? At some point you’ll need to free a piece with a utility knife if you’re not using proofgrade.

If they are just going to engrave piece of wood that is less than 2" in height, and fits in the machine, settings don’t really matter. Engrave it and if it isn’t deep enough do it again (just don’t move it.)

[cindy.burns]

I have 9-12. Thanks for the info. I think will work with proofgrade until we get comfortable. Then venture out.