Laser speed settings + 200 mW vs 1600 mW (vs ?)

Question about the laser engraving speeds. I just staretd with engraving with the printer I got last week.

I’m engraving (ply)wood right now, a 10x10 cm square with my 200 mW laser module that came with the machine. I made an image using powerpoint, and turned that into a .png. It contains text and shapes, if that matters. I’d say 80% of the surface is still empty, the rest is text and lines of shapes.

I made the Gcode based on the vector option, but with 20 fill in the editor because I my gut says that it’s the most accurate one (don’t know much about it really) and gives black filled in text and thick lines. Using the snapmaker laser guide I found settings 1000 working speed and 1000 jog.

It works, the image looks nice. Except it takes a LONG time. Easily over an hour for a 10x10 cm area. Is this normal? What are the things I can do to increase the speed?

Now the thing I came up with: getting the 1600 mW module. I imagined that it would go faster with it. Looking at the guide from snapmaker, they suggest for the same material working and jog speed of 1500 also at 100% power. Is this accurate? Only a 50% speed increase with a module with 8x the power? It seems counter-intuitive. Also, I read somewhere that a new laser is in development. That would be interesting.

Any tips on speeding this up are appreciated!

An hour is not long :laughing: Several laser jobs I’ve done run for 20+ hours.

Ways to speed it up: 1) more powerful laser 2) smaller jobs with fewer lines

Yea, laser power is not linearly related to speed. If you want to go very fast you would need a 40W laser, or more.

Subtle design tweaks can speed up things. Fill less than 20%. Make lines slightly thinner.

Perform material testing to find the fastest travel speed at 100% power that gives you acceptable results.

Thanks Brent!
I just checked my jog speed, and it was actually 3000 (not 1000).
I guess my expectations were off then. Still since I want to engrave several dozens of the same image (making invitations on 10x10 cm coasters) any gain in speed is welcome.

So for the vector option: fill at less than 20.

Would going B&W or grayscale help? Are there ways that can make these specifically faster while still having clear text?

So thinner lines and testing with speed, got it. Somehow I do not expect that this will make a lot of difference (but surely a few percent), because the laser still has to move over every area while jogging. Or am I imagining this wrong?

What can I do with the image itself (except making the line thickness in powerpoint of my shapes lower) to increase the speeds?

TRIGGERED

Lol. Are you doing this in Luban? I think I’m used to Lightburn where grayscale means something different than it does in Luban. I don’t know anything about the different modes in Luban.

I, with modified firmware to support this, do a continuously variable laser power with a single outline engraving at the end. Gives great results, is “extremely” fast, and fills 100%.

The trick is optimizing the number of times the machine needs to decelerate and accelerate. If you have the machine speed set to 3000mm/min, it will never reach that if every travel is going only a fraction of a mm, because there’s not enough distance for the machine to accelerate. Dithered patterns are particularly slow for that reason.

If you can do solid lines that allow the machine to travel at a maximum set speed for a long time then that will drastically speed things up.

The picture I’m trying to paint here is if you’re dedicated to optimizing throughput on your machine you’ll need to learn about the motion control the machine uses, so that you can modify your designs to eliminate as much slowdown as possible. Otherwise, just be at peace with jobs taking many hours. Even with heavy optimization you likely won’t cut the time down by more than a factor of 2 or so. The laser just isn’t powerful enough to burn while travelling at warp speed.

Hi Brent. Thanks again :slight_smile:

Yes, Luban. I’m new to this. I must say the software is user friendly, which I like. However, optimization is needed here. I have seen that the same image which takes 90 minutes with filled lines takes less than 10 without filled lines (essentially just the borders of everything).
The big difference I see between the 2 settings is that when I select fill, it starts at the bottom, and moves in straight horizontal lines, line by line making the image for the next 90 minutes.
When I don’t select that one option of fill, with otherwise the same settings, it traces exactly the borders of all the text and shapes.
So my question to you: would this method also work for ‘filling’ the text? Doing it essentially letter by letter instead of row by row? Is that something that Luban can do (I guess not by your response), or can I do this with other software? If so, which one and where should I start? Thanks!

I think I follow you, but let me know if not. I think the answer is simple, the total length of the path traced by the laser when filling is just much much longer.

It doesn’t really matter if the path goes side to side or any other way, it sounds like just tracing the outline has roughly 1/10th as much distance to travel, so it’s much faster.

Sure, I don’t think it’ll affect the time though. Same amount of area needs to be covered by a very thin laser. Just takes a lot of passes. Some software does give you that option, but it’s purely an aesthetic choice, having concentric paths rather than parallel.

I usually fill assuming the laser has a 0.1mm wide kerf. If you need to fill 1 square centimeter, that will require 100 parallel trips, each 1cm wide, for a total travel of 100cm. If your work speed is 200mm/min then that will take at minimum 5 minutes to traverse, not including time to stop and change direction.

You posted your jog speed earlier (3000mm/min), which isn’t particularly relevant to the time here, because in this square filling example the only jogging occurs when the laser is off, which would be moving 0.1mm up to the next parallel row. The distance is miniscule, and doesn’t save any time over a jog speed of 1000mm/min since the toolhead can’t accelerate to full speed in that time anyways.

Thanks Brent.
I’ll check what happens when I play around with the fill settings and how it affects the blackness, and I will look at my image some more. You’ve been very helpful :slight_smile: .
I think I automatically assumed I was doing something wrong because in the video’s I watched, it all went a lot faster.

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The owl engraving sample that got used in a lot of promos, they posted the time somewhere that I can’t find right now. I think it was 13 hours or something.