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Perry Holbrook
11-14-2004, 8:23 PM
I'm designing several new items to add to my current line for next years shows. One item may include laser engraving in either 1/8" ply or solid hardwood.
My beginning questions: 1. Can photographs be scanned and engraved into the wood? 2. Can other print matter such as wedding anouncements, etc be scanned and engraved. 3. How much can I expect to pay for the above if the image would be around 5" x 7" ? 4. If this works out and I'd like to throw the business to Creek members, do I do that thru the classified forum?

Thanks for your help.
Perry

Keith Outten
11-14-2004, 8:53 PM
Perry,

Photographs, wedding announcements, birth certificates, etc can all be scanned and engraved on wood. Your best choices for wood that engraves well are cherry, alder, maple, hickory...but there is also a list of woods that don't engrave well like oak and pine.

You can ask for quotes in our classified forum, I'm sure that several of our members will be glad to provide you with some attractive numbers.

Rodne Gold
11-14-2004, 11:46 PM
You can engrave just about anything either scanned only , or a combination of scanning and real vector based text (small text scanned will not engrave well or crisply) , however suffice it to say that if it can be printed , it can be engraved.
Even 1/8th wood , if high in resin , can be problematic to cut without higher powered lasers and will always exhibit a burnt look if processed with low power machines.
In laser engraving , time is money , so it would depend on time of lasering as to price. Artwork too will be problematic , for example we would like the originals and to scan and process them ourselves rather than accepting your scan etc. We then have total control of output. This too would cost.
One needs highish contrast between engraved and unengraved sections , thus dark woods dont engrave well , so lighter woods work better. The resin content of the wood is also important as woods with high resin contents tend to "burn" or boil the resin and this vaporises and recondenses elsewhere and "stains" the wood. (Thus we generally laser sanded and sealed plaques rather than raw wood , its easy to wipe resin residue off sealed surfaces)
Power , resin content etc is actually a double edged sword. High laser powers will actually engrave wood well , whether "well" is good is another story.
Basically the laser does not "burn" anything , it vaporises or ablates it. The better the beam quality and the higher the power , the less there is a heat affected zone. For example a lighter and a blowtorch will burn a hole in a piece of paper , a blowtorch will burn a neat hole with little charring , a lighter will have a lot of charring.
The "Charring" around the "hole" a laser burns (lasers burn "holes" , they pulse so many times per second , almost like using a jack hammer to draw a picture) actually gives a lot of the contrast - if you vaporised the resin and wood cells , you would get a VERY clean cut with almost no contrast and would have to fill it with something dark to even see it properly. So for "nice" wood engraving , you need to actually create a heat affected zone which is counter intuitive to what a laser SHOULD do.
Thus for wood , its often a better bet to use a laser with lower power , with a larger spot size (IE less power in a set area) and to set it so it DOES burn and not vaporise.

I'm in South Africa , so wouldnt be at all interested in quoting on this , suffice it to say we charge a minimum of $1 per minute of laser time on very high quantity. A lot depends on the laser as to how long it takes to engrave this image.

Thin woods are also VERY problematic with a laser , they are often warped or warp during lasering and become difficult to engrave and almost impossible to cut effectively as they warp.

We use a 3mm low density supawood type material and have it laminated with real veneer each side instead of solids , the supawood is light and always lasers darkish due to its resin(whatever it uses ) binder and the veneer had "controllable" grain. Apart from whuch the low density fibre board inside cuts really well and predictably with lower powers.
One of the problems with real hardwood is the fact that the grain has variable hardnesses and resin content as well as colour and apart from the colour interfereing , the grain itself will modify the depth of engraving and the setting that gave high contrast on the realtively grain/knot free section might not work as well on the grained section. you often see the grain structure at the bottom of the engraving and this can be obtrusive or not - depending on the image.