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Brian Tymchak
10-31-2009, 1:33 PM
Hi all,

First time poster in this forum. I've been lurking along for a while trying to absorb all I can about using a laser. The collective knowledge and experience of all of you that participate in this forum amazes me, as well as your willingness to help one another. Hopefully at some point I can contribute at the same level.

I have an idea for a product and am trying to figure out some aspects of building it. I have some questions that I hope someone on the forum might be able to help me with. I don't have a laser yet nor any experience with one. I'm hoping to get a better understanding of what my process would be before I sink the $$$ into the equipment.

The product will have a wood veneer ( .028" ) surface with inlay over a thin wood substrate, with overall thickness of about 1/4" or so. My current plan is to cut the inlay pieces with a laser. The final shape would also be cut from a larger sheet with a laser.

Here are my questions:

1. Are there considerations I should keep in mind about the adhesives I use in the product so that there are no issues, i.e. flames, when cutting with a laser? I've built a few initial prototypes using contact cement, although I don't know if it will be my final choice.

2. The inlay will consist of many small pieces of veneer. As an example, think of a 5 point star only about 1/8" wide point to point. I think I would need to use some sort of a vacuum table to keep the veneer flat during cutting. I’m wondering how to capture these small pieces as they are cut. Does anyone cut very small pieces like this on their laser? Would a vacuum system present problems with pieces this small? Wouldn't want the pieces getting sucked out the back of the cabinet... If I were to just tape a veneer sheet to a sacrificial piece of MDF, instead of using a vacuum table, would the small pieces remain in place where they are cut instead of flying away or into the path of the laser?

3. If my business plan holds up, I may need to cut thousands of those small veneer pieces of various shapes each week. Is a laser a good choice for this kind of volume cutting?

I would greatly appreciate any advice anyone can offer on these questions.

Thanks for your help,
Brian

Lee DeRaud
10-31-2009, 2:12 PM
Adhesives: unless you're talking about huge (dining-table-sized) assemblies, I'd use 4mil PSA, applied to the veneer before cutting. (If you're talking about common species of wood rather than exotics, you can buy the veneer with the PSA already on it.)

As far as cutting small pieces, I sometimes do exactly what you describe: cut over a sacrificial piece of 1/4" MDF. If you're really good and the veneer is really uniform, you can sometimes get your settings so the laser cuts through the veneer and adhesive film (see above) but not all the way through the backing paper. Not something to count on for a production process through. Most of the time, I just deal with the occasional lost small piece by cutting another one...again, that could be a production process issue.

But quite frankly, I think you're going to find that assembly time is going to be a much bigger factor than cutting time anyway.

Dan Hintz
10-31-2009, 4:29 PM
If you have a large number of varying shapes, the laser is ideal for such an application. If you have a very limited number of shapes, a die press may prove more economical.

Joe Pelonio
10-31-2009, 4:45 PM
For large quantities see my post on cutting paper:

http://www.sawmillcreek.org/showthread.php?t=122155

I also do veneer, and often attach it to MDF with temporary spray adhesive. It hasn't seemed to bother the adhesion of the glue when I apply it to the wood. The base I engrave out into the shape of the veneer pieces, not quite to the same depth, to allow for some sanding before applying the finish.

Bruce Volden
10-31-2009, 6:37 PM
think of a 5 point star only about 1/8" wide point to point.




On something this small you would need to "break" the lines apart or you may end up with something LESS than 1/8" point to point. The laser will "hog out" sharp points when it cuts a CONTINOUS kerf, but by using 10 "broken" lines in the stars shape it will work fine. I found this out using MOP and Paua in some of my inlay techniques when they didn't fit the receiving object uniformly. Just something to keep in mind. This is not a big deal to accomplish in Corel. My $0.02 worth. :cool:

Bruce

David Fairfield
11-01-2009, 5:48 AM
Good point Bruce. When a sharp angle is necessary, best to break up the lines so the laser isn't whipping around corners while firing. So for example if I need a precise rectangle, I'll draw two parallel lines, then slice (or butt) the ends with another set of two parallel lines. That renders nice sharp corners. Had I justdrawn a rectangle, under magnification I'd see rounded corners and possibly a bump or a divet near the corner.

Don't forget offsets for kerf. With a .007" kerf, the offset is .0035"

Dave

Lee DeRaud
11-01-2009, 10:28 AM
So for example if I need a precise rectangle, I'll draw two parallel lines, then slice (or butt) the ends with another set of two parallel lines.You may need to turn off vector optimization for that to work, depending on how aggressive your machine's driver is. (The one on my ULS sometimes thinks it's smarter than I am.:cool:)

Brian Tymchak
11-01-2009, 4:46 PM
If you have a large number of varying shapes, the laser is ideal for such an application. If you have a very limited number of shapes, a die press may prove more economical.

Actually, when I first thought about this several years ago, I didn't even know about laser cutters. A die press or some other stamping process was my first thought. But, I didn't have any knowledge of those kinds of tools and I also realized I would have a large number of shapes to cut, and that all led to me not doing much back then. Now, I think the best idea is to start out with a laser and then, a bit later, look at a die press for the shapes I know I will use extensively. Out of curiosity, I just did a quick search for die presses and found a small one for about $1700. That surprised me. I figured they would be at a much higher price.

Brian Tymchak
11-01-2009, 5:04 PM
I also do veneer, and often attach it to MDF with temporary spray adhesive. It hasn't seemed to bother the adhesion of the glue when I apply it to the wood.

Joe, that's interesting. What do you use as a temporary spray adhesive, and, what method do you use to release the pieces from the MDF after cutting? A razor scraper or something like that?

Thanks, Brian