Author Topic: Why Cutting Woods is Problematic  (Read 1738 times)

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Why Cutting Woods is Problematic
« on: February 21, 2016, 06:47:57 PM »
So I started to post my results of my materials test cutting (see the other thread in this category).

As you probably know, these low cost, low powered lasers were never intended to cut anything. They were designed to engrave only (not etch). However, I wanted to find out if I could cut wood and acrylics. As you can see from my cutting results, the answer is YES you can cut 3mm wood and 3mm acrylic - however - for the woods, the cutting is problematic. What do I mean by that?

Because we're dealing with very low powered lasers (mine is 2.5 watts) the grain of the wood impacts the cutting results and thus the success. My test cuts have been one inch squares. I discovered that cutting along the grain takes less Feed speed that cutting across the grain. Thus, to get an evenly cut shape, such as a square, you actually need to change the Feed speed depending upon which direction of the grain your line is moving on. Obviously, higher power lasers don't have to worry about this...but we do. And this is not an issue for cutting acrylics, only for cutting woods.

My tests have been manually written in gcode and saved for each material. So how do I plan to actually use this new found ability to cut wood...evenly...going across and going with the grains? Early on, I knew that if I could cut wood at all, a key piece of being able to do this would come from the CAM software being used. Unfortunately, there is almost no CAM software out there that was made to support our low cost lasers. The key to making this workable and usable is in how you define your toolpaths.

While there are a few CAM software packages out there that can be used, they have so many non-laser related settings to worry about, you can get easily lost trying to make one of them work. I was not happy with any of them. The solution was CAM software written specifically to support low cost lasers.

There is another thread I started regarding my working with various companies and individuals who have developed CAM software to see if they would support this growing market. One company is working with me but they are slow to communicate with me. One developer is working with me and he is modifying his CAM software to support our low end lasers.

Once we have this CAM software, then, for the first time, we will have a usable laser machine with which we can turn out some pretty neat things. And all on the low end of the price scale!

I plan to make a tutorial video on how to use this CAM software once it is ready. For our usage, there will be a slightly different way in which we will have to interact with all the toolpaths that you don't have to do if you're using normal CNC CAM software toolpaths. I'll save the details of this for the video but I can tell you now it has to do with whether or not your lines are running with or against the grain.
« Last Edit: February 21, 2016, 06:53:09 PM by Administrator »
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ROSS

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Re: Why Cutting Woods is Problematic
« Reply #1 on: February 22, 2016, 12:52:52 AM »
Having read up a lot about these Banggood Chinese lasers in which people mentioned they were only good for engraving/etching or burning wood  I have bought a 5 watt laser to add to my mechanics  which is  REPUTED to cut 3mm thick wood with three or four passes.....
We will see when the laser head arrives.

As regards cutting PLY.  I believe, that many who buy these LOW POWERED lasers do not understand that the uual type of plywood encountered is unsuitable for less than very powerful lasers.....and if you  want a higher powered  Banggood laser to cut it,then LASER PLY  is the one to use..BIRCH PLY.... as its  laminations glue is different to the usual  glue used in the ply available from DIY timber sellers or Mall retailers....it is specific to laser ply.
Laser ply is cleaner when being cut (mainly due to the quality glue used).......(Its also more expensive).

There are different grades so check it carefully.  B on the topside and BB on the underside is a good laser ply.
You can buy AA/AB laser ply but need a deep pocket or fat wallet!

Read this..I have no connection with the firm mentioned.

https://hobarts.com/sheet-materials/wood/laser-ply-information_124_15_147/


« Last Edit: February 27, 2016, 12:38:50 AM by ROSS »
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Lasers are wonderful machines..not ONLY  can they cut a finger off BUT  they can also cauterise it at the same time.....

SAFETY -  IS NO ACCIDENT