[brian257]

I have attached a picture of a rocker switch that I have been doing some test engraving on. I am using a cheapie Chinese K40 laser with the Lightobject DSP upgrade. This switch was already factory engraved. If you look at the winch symbol in the middle of the switch and the word "WINCH" engraved near the top (upside down) you can see that the engraving is perfect. The edges are very crisp and clear and the engraving depth is very shallow and completely consistent over the engraved area. It is also a good milky white and easy to read (switch is white translucent backlight plastic with a very thin black surface that is engraved through). For reference, the letters are little under an eighth of an inch tall.

Now when you look at the parts I engraved (words "ANCHOR LIGHT" and the light symbol you can see that my results are nowhere near as good. It looks like melted plastic and has been turned shiney and translucent instead of the milky white. The edges are nowhere near as crisp and defined. If you look at the very lightly engraved "LIGHT" at the bottom you can see that it was not enough power to go all the way through the black, but as soon as I use enough power to go through the black it engraves many times deeper than the factory engraving and gives me the melted translucent surface instead of the milky white (and I have cut the plastic and verified that it is milky white very deep, it is not just that I am engraving too deeply, just melting the plastic).

I have tried different speeds and power settings. I did some with a shorter focal length lens than this and got better results, but still not good.

Can anyone tell me why I am getting such bad results? I understand that I am not using a professional expensive laser, but is there anything I can change to at least get better results? Do I need a higher quality tube, do I need better quality optics, is it the difference between a glass tube and an RF tube, is it something with my settings? Any help would be greatly appreciated.

Attachment 246976

[mondo50m]

What power and speed are you using? What is your DPI and the scan gap that you are using?

Milt

[brian257]

I have tried a ton of power and speed settings. Best so far seems to be about 5% power (appx. 35W laser) and about 400 mm/s speed. My scan gap is .1mm. The LaserCad software does not have a DPI setting. They do have a PPI setting, but I have played with it and did not see a lot of difference other than having to up the power with PPI turned on.

[mondo50m]

.1mm scan gap is good for about 200 to 300 dpi. You must be using the laser cad software to do your text? I use Corel Draw to to do all of my graphics and text. I can then set the DPI that I want to use and once in Lasercad I change the scan gap to match the DPI. I am no expert in this stuff, but that is how I do it. Also, I have a 1" or 25.4mm focus lens to do the really fine engraving. I would be interested in other opinions on this subject also.

Milt

[brian257]

Thanks Milt. After talking to Marco at lightobject I did order a 38.5 mm lens and I picked up a copy of Corel today. I had been using exploded AutoCad text. I send some switch blanks to Marco today also and he is going to try some things on his machines and see if he can help me get good results.

I have recommended Lightobject here several times before and will continue to do so. Aside from a great DSP controller and good software Marco is very helpful. Great company to work with.

[mondo50m]

Ditto!!

Milt