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Paul Grothouse
12-29-2011, 11:43 PM
OK, I don't usually do a lot of vector cutting of wood with my laser.

I thought I make a few ornaments for the kids, snowflakes, snowman, etc.

Well 2 hours and a lot of cussing later I had 3 ornaments and and pile of charred up waste.

So my question, how do you work out settings for wood vector cutting. I noticed it varies greatly with wood density. I'm interested in what processes you fellow Creeker's use to zoom on the best settings.

For reference I have a Universal 120W, and was using a 2" focal lens. Material thickness was 1/8" to 1/4".

Dan Hintz
12-30-2011, 6:55 AM
With 120W to work with, you should have nooooo problem. Wood wants a low frequency shot (500Hz, give or take) and a relatively slow speed. You need to "pop" it with a lot of power on each shot, but make the pops far enough apart that they don't heavily char the wood.

Mike Null
12-30-2011, 7:02 AM
Not all wood is created equal. Some woods, such as most conifers, have different density growth rings that they engrave and cut rather poorly when compared to hard woods like birch, walnut, maple, cherry and others which have a more uniform grain.

I think as you experiment with your settings you'll find that you'll get best results with settings for nearly every kind of wood.

With that much power you actually may be using too much or you need to increase your cutting speed. Dan pointed out the frequency issue and again you may find different settings for different woods works better.

Dan Hintz
12-30-2011, 7:04 AM
Good points, Mike... and don't forget, air assist can be a big help here, too.

Kim Vellore
12-30-2011, 2:13 PM
Lighter and softer the wood less the charring. High density wood and wood with higher oil/resin charrs more. Balsa does not charr.
Kim

Michael Kowalczyk
12-30-2011, 4:22 PM
Make sure you focus in a few places. Sometimes I do all 4 corners to make sure it lays flat. If not I average it. With 120 watts you should breeze through it. For My Trotec Speedy II 60 watt laser with a 2" lens I use the following. 100% power, 1.15 % speed (this will be different than yours but is fairly quick on mine), 5000hz (again this may be different on yours but it is in the middle for me) and air assist is always on.

If you search some of my older posts you will find one with a picture showing the golden brown edge we consistently get with our 3mm & 6mm Genuine Baltic Birch plywood that we use as well as supply. Charring can also be caused by exterior glue ors is interior glue and CARB II certified. If you are getting flash back on the back side you are either going to slow, using a honeycomb table or your material is not high enough away from the table and getting a bounce back of the laser. make a bunch of circles or squares and color map them at different speeds. Watch for them to drop and be consistent but remember what works for one may not work on all. Baltic Birch can be .113" one time and the next it can be .126". Always use a digital caliper so you know what you are working with.

Sometimes harbor Frieght has them on sale for $8-$10.00 for plastic ones that aren't as accurate and only go 2 decimals places and a 6" metal one they have for $19.99 but I bought 4 of them when they were on sale for around $10.00 each. This way we have one at each machine and I have one in my office.

I made a Pin table that is high enough and out of a material that absorbs the laser instead of reflecting it so flashback is usually not an issue for me.

Let me know if I can help and ...

Paul Grothouse
12-30-2011, 9:08 PM
Good feedback guys. I have to turn the power way down or it vaporizes the wood. I do have air assist, I don't have a honeycomb table so I used a drop ceiling light grid.

I was getting varied results, best seemed to be 45% power, 1.5%speed and 40PPI.

If I lower the PPI it looks like a bunch of tabs, increase the power FIRE.

I am not sure how PPI translates to Hz.

I just feel like I am doing something majorly wrong.

Mike Null
12-31-2011, 7:50 AM
Paul

You need airflow under your cutting grid. It won't work properly if it's just set on the table. PPI and hertz are probably the same on your machine.

This should be a breeze with all that power so something is wrong with your method--focus, table, settings ????

Khalid Nazim
12-31-2011, 3:35 PM
I regularly cut 1/4 and 1/8 BB and my settings:

1/4 BB - S=10mm/sec and P=70%.
1/8 BB - S=10mm/sec and P=40%

Its possible that you are going too slow with too much power. You can try extrapolating my settings for your machine and trying it out.

Regards
Khalid