Here is my first test on a piece of MDF: Have yet to work out how to trace a single line, not an outline. I hope this will clean up the overburn on the small details. Then i can use focal length by changing the z axis to get a finer or thicker burn line. That does not look too bad. MDF responds differently than paint. Try a painted piece of cast plastic during one of your next test to see what you get. Also, what is the max dpi you can expect to achieve with the laser you have? My guess is you are around 200 to 250 dpi. Thanks Will for the update. This is very exciting to see what we might be able to achieve on our own. The dpi only matters if he has the laser module set to pulse and is doing a raster operation. If I were to use this on my CNC I would turn down the power and set the laser to be always on. Using a pocket operation (vector) on the text should work to burn away the paint character by character. This way the laser will draw the text like an engraver would instead of doing a line scan pattern (where dpi comes in). the beautiful thing about this type of laser module and it’s wavelength is that it shouldn’t even engrave the acrylic so you should be able to easily burn the paint away leaving a clean acrylic surface behind. The question is how clean the paint will burn away in the sides. Really looking forward to seeing results on painted acrylic. Yes, I use vector graphics, its far more efficient and easier to use, and to code. I have done some test burns on a piece of acrylic painted with Testors gunship grey. Created a test file in Fusion 360 from Rons audio control panel drawing. Post processed using pocket, trace, and engraving, having defined a tool with a tip of 0.3mm. Output from F360 was interesting, i could only find a config file for laser cutter in .nc format, not .tap which I use in Mach3. They are not quite interchangable. Add to that I am using M3 & M5 for laser on & off, whereas the .nc output was M10 & M11 (which is better but my older controller doesn't like them), so a lot of time was spent code tweaking. Finally I got to burn paint. Made 3 runs (see photo) at different power settings. these were: 1: 30% power (small text 20%) 2: 50% power (small text 30%) 3: 100% power (Large text 80%; small text 30%) and backlit by a LED array torch: I have uploaded 3 indivdiual photos if you want to look more closely. If you do you will notice a the beginning of many of the text letters there is a dot. This is caused by using M3 & M5 (even with zero spindle spin up delay set). Hey Will, Looking very promising! I see the "dots" you are talking about, especially at the bottom of rectangles and circles. You might be able to minimize that effect if you are able to tweak where the engraving starts. But that would be difficult to do I think. The good news is the circles where it is most noticeable will be cut with the CNC. Judging by the photos, it looks like your second set of setting works best. I think if we are able to tune the settings and figure out a way to get around the "dot" issue, this will be a great way for folks to take on their own engraving with a laser. Two quick questions, did you see the post I put up about the Gunship Gray paint no longer being available? Looks like we are being forced to make a paint change, see this post HERE Other quick question, the words "ID" and "VOICE" on either side of the BOTH knob, what happened to the artwork there? I know this was just a test piece but it is the little things like this that you might not have noticed until after the laser engraving has been done. And we know what that means, we end up with a wasted piece of effort and I have no more hair to pull out! LOL A technique I found on YouTube to determine settings. One runs the g-code on any material to see which is best setting. I have not tried yet but seems valuable. A matrix of power settings vs. Number of passes in increments of 10. I'm building the matrix now. Time consuming. Will post the g-code when I'm done. Not sure I want to go above 50 passes. A question, Will. You mentioned your laser is 15w. Is that input or output. I found Chinese lasers (especially on Amazon) describes the input power without saying it's input or output. It would be important with the percent of power. What are the number of passes? Ron, I agree that set 2 is best. I think the only way to lose the lead-in dots is to upgrade my controller card to one that is happy with M10 & M11 commands. Yes i saw your post re paint, i still have some testors. We get Rustoleum here in OZ. Congrats, you passed my ‘who is observant’ test! Yes I noticed the “D” & “C” when I was burning them, but as a test piece it wasn’t worth redoing. I obviously selected the place holding shape, not the character. My learning for next time. Dave, I presume it’s input, I have no idea on output. I figured on testing to find the right power and passes, that way I find what’s right for my setup. I dont need to know the output power. It is all one pass at 1,000mm/min. I like the matrix idea. Given that I think I get good coverage on one pass I might create one using power and feed rate as my variables. It would be good to use some of the smaller text from the ACP as well as some shapes and large text in the matrix. I have done a test grid using power(%) and feed rate (mm/min). The grid lines and axis labels were all done at 50% & 1000mm/min (50/1000). The grid is 25mm squares, overall stock size was 300x400mm. As you can see I used a pattern with lines, shapes, and large and small text. An aside, should I choose to do this again I would only do 1 line using the diagonal values from the grid (ie: 10/100, 20/200, 30/300...) To my eye there is a little bit of sharpness change over the grid, but its quite subtle - nowhere near what i was expecting. I think I will stick with 50%/1000mm for normal engraving, and 30/1000 for the small text. For me the more interesting learning was this "if I'm doing this I might as well do that" moment as follows: I also did a Z axis comparison (the Height Focus Check at bottom and right) where I varied only the Z axis, power & feed rate stayed at 50/1000. There are 2 patterns as I did the bottom one first (+-1mm at 0.2mm steps) and didn't see much difference, so I tried 0.5mm spacing for +-5mm. OK, so a little typo slipped through and the +2.5 became +22.5. This was interesting as I cant really see any difference in line thickness over a range of 27.5mm (-5 to +22.5), even at +22.5 where the line is indistinguishably different apart from not burning as deep (which is why it looks lighter). I was expecting burn width to change with height, similar to a magnifying glass in the sun, but I now think the focus ring on my laser focuses the beam regardless of distance - at least the small distance we have on our CNC Z axis. All in all, an interesting test that has taught me something! If anyone is interested I have a 6mb original and a backlit image - PM me if you want it. FYI: I created the pattern in Fusion 360, filling only 1 square with the pattern (10/100). Then processed that square to a G-Code.tap file. Modified the .tap file to suit a laser cutter (ie remove all Z moves and add laser ON/OFF commands). Then I used excel to make all other squares by dissecting, adding the grid spacing to X and Y values, reassembling, as appropriate. I am happy to share if anybody wants. Hey guys, somehow I missed some of these recent post. Good find Dave on the power/passes matrix! And a really good report Will! It is amazing what you are able to do with a small relatively inexpensive laser head. Reading through your post, it looks like one of the biggest pains is altering the G-code. Can you email me your sample of G-code and the 6mb original with backlit image? One day I want to move forward with my own laser and the work you are doing here is pushing me hard in that direction. If nothing else, I would use a laser like this for smaller jobs. Thanks Will for the detailed update! Will, Beautifully done. Some advice, please. I cannot get the laser I purchased to work. Can't get the registration to work. Been on the phone for a total of 5 hours. Still doesn't light up. Unfortunately, the laser you purchased won't ship to the USA. I would like to try something similar (Amazon 15w). Two questions if I may, 1. Where does one find out how to wire the control board (less power), and 2. How do you align it on the X and Y axis? Mine inserts into the router so I align it with a bit first. How is it aligned with the laser lens offset? Thanks Engraving Text
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