As a hobby project, I converted my unused and forgotten Ender 3 3D printer into a laser engraver. I’m completely new to this topic.
For the past few days, I’ve been struggling with wasted test samples and the fumes of burned rubber…
I have a 3D-printed rubber sample made from Spectrum Filaments S-Flex 98A. What I want to achieve is a matte, smooth top surface so that the print lines are no longer visible.
I’ve tried different speeds and power settings, but the best results so far came with:
Speed: 10,000 mm/min
Power: 15% of a 10W laser (so, 1.5W)
Line interval: 0.01 mm
Number of passes: 1
With these settings, I achieved a surface similar to brushed aluminum.
Higher power removed too much material and generally burned the rubber.
Setup:
Laser module: Ender 3 Falcon 10W
Controller: GRBL-M3 (1.1e or earlier)
Software: LightBurn 1.7.06
MacBook with Sonoma
The photo I attached shows a surface sanded with sandpaper, where the 3D print lines are still visible.
Can anyone suggest how to achieve a smooth but matte surface?
Or what settings to adjust and what to leave unchanged?
Thanks in advance – a completely clueless hobbyist.
Basically, a laser is the wrong hammer for the job.
Although the filament is a thermoplastic, molding it into a particular shape requires both well-controlled heat and considerable mechanical pressure. Applying only energy to the surface in the form of a laser beam will do:
Nothing = not enough heat
Burn small protrusions = barely enough heat
Char the surface = too much heat
The surface will not get all melty and slump into a smooth layer without pressure.
However, PrusaSlicer has an “ironing mode” to run the printer nozzle over the finished top layer to flatten it:
If whatever slicer you’re using has an ironing mode, give it a try; it’ll surely work better than the laser.
Thank you very much for your well-informed response.
Let me clarify.
Due to the complex structure of the printed model, the layer I want to finish is the first layer, which is applied directly to the 3D printer’s build plate. If the model were flipped, I would have too many overhangs, which would require support structures that are difficult to remove later.
It doesn’t have to be a perfectly smooth surface; it can even be slightly rough, with visible lines—something like brushed aluminum. I just want to get rid of the noticeable print lines.
Prusa has a bewildering variety of coatings and surface finishes, but that’s the only one I’ve tried.
The usual first-layer lines vanish in the slightly nubbly texture without any special attention, even in a multi-material object like that shim. Single-color objects have the same nubbly finish, of course.
Prusa has some cautions about PLA on that surface and their sheet probably won’t fit your printer, but if something similar is available, definitely try it!
I don’t think this can be accomplished using a laser. A laser is not well suited to burn to a specific depth. You either engrave with varying engraving depth, or cut through. There is nothing like “engrave 1mm deep”. You can try, but results will never be predictable.
Here is an example. I used the laser to create a template / jig for engraving plates. As you can see, the surface of the holes is very rough and differs from hole to hole. There are many factors that play a role here. A laser is a really bad tool for this. A CNC is way better.
Thank you for the advice. I’m already feeling bad because you’re trying to help, but I think I have to complicate things again. I have those textured steel plates for my other, smaller printers. Unfortunately, for the printer I use to print with rubber, a 600mm x 600mm plate is required. I do have one… but unfortunately, the rubber pulls it up, and the prints get ruined. After several attempts, I gave up on it and now print directly on the aluminum bed.
I don’t know much about laser engraving, as I mentioned earlier. In general, the laser is meant for engraving on plastic prints, but I thought maybe it could work with rubber as well. I see now that it probably won’t.
I just did a test using acetone, and while it does create a slightly matte surface, which looks much more interesting, it’s still not exactly what I’m aiming for. Maybe my expectations are too high. But I really appreciate the tip about acetone. I’ve used it before, but only on plastics. Thanks anyway!
I’ll keep experimenting a bit with the laser passes. Any suggestions? Higher speed and lower power? Am I heading in the right direction?
Sounds good. But if you don’t see any effect, do the other way around. You can also try to move the head up some distance, which brings it out of focus and a wider beam might be beneficial. Lasering is all about testing Check what’s working best
You have the DPI (LPI) set at 254. Your 10w laser should be capable of 318 DPI (.08mm Interval). If your goal is to remove the lines, try increasing the DPI and possibly use Crosshatch.
Check what’s working best