Creating grayscale images with Linksprite 3 axis CNC/Laser engraver
Okay, here's where we get to the meat of the problem. I'm going to try to provide as many pictures and links as I can so people know exactly what I'm working with, and I can follow any step by step instructions as long as you understand I may not understand the directions, I'm just following them.
First, the preamble and background:
I purchased a linksprite 3 axis CNC machine from my local Microcenter. It also apparently uses a woodcutter CNC board?
Originally I wanted to use it as a CNC machine (as it is designed to be used) but after playing with the CNC functions I quickly learned that this **** isn't for dumb idiots like me and I kind of need to know how to deal with code and electronics and a lot of other things. I think with the right guide I could figure it out, but that's a different problem.
I decided instead to purchase a laser engraver head for the machine. This sucker is a 500 mw, 12v laser and so far it actually works great. I'm learning how to calibrate the machine for size and detail, and I'm learning what a lot of the functions within the software (laser GRBL v2.8.19) can do. I've vectorized some images and so far I can engrave plastic (sort of), wood, and leather. In one 'color.' Here's some examples:
And now the problem. I want to engrave in grayscale. That's not working so great.
I know that LaserGRBL allows for grayscale. I can see where it talks about how to engrave in grayscale, and I've played with the contrasts and brightnesses and all that. It says my machine needs to support PWM in order to use grayscale though, and that's where I'm getting confused.
In order to engrave the plastic correctly, I had to increase the power on the laser. Compare the 255 strength with the 550 here:
So how exactly do I figure out whether this equipment supports PWM? Is that a function of the control board, or the laser itself? Does the fact that I was able to do this mean that the engraver supports PWM? And I've got two follow up questions depending on the answer to that one.
1. If it DOES support PWM, then what am I doing wrong with grayscale engraving?
Most of the grayscale attempts I've done have come out looking like this:
And the absolute best one I've managed so far looks like this:
That is literally an intensity of 35 on the black one, and I think 33 on the 'good' one. The default setting was 255. Setting it to 30 usually means it leaves no mark on the wood at all.
What do I need to change or fix in order to make this look better? I've got a laser engraved keychain a friend made years ago that looks leagues better than this thing, where details are clear and the contrast is pretty high between the 'colors' they engraved. Mine has detail but it looks like the only major difference is how close together some of the dots are, not that they are actually 'lighter' or 'darker.' Do they need to just be spaced out more? What do I need to look into learning in order to properly create grayscale engravings with my equipment?
2. If it doesn't support PWM, is there a relatively accessible means of making it support that feature? Could I, say, remove the control board and put in an arduino control board instead?The frame and motors work great, if it's not super involved to just 'recycle' those parts and give this thing a better brain then I would be interested in learning how to do that.
If I can't do that then honestly that wouldn't be too upsetting, as engraving in one color still has some pretty good uses. The machine is very small, and can only work with a space of about 5x7 inches, but that's room enough for keychains and wallets and what have you.
Thanks in advance to anyone who reads this whole thing, and I can't wait to speak with people and improve this skill! Let me know what other info is needed, if any is needed.
Creating grayscale images with Linksprite 3 axis CNC/Laser engraver
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