I am having issues of vertical lines appearing when engraving powder coated tumblers with rotary and Luban. They appear to be consistent when they appear with every project but only on left half of graphic. Why would they be vertical when the rotary is operating on horizontal mode.? Have tried varying power up and down but doesn’t change outcome. Speed is 1000mm/min and power from 35% to 45%. Could rotary be the issue or is it a software issue… Any help is greatly appreciated…
Can you post a photo? And: Which laser module? What kind of image you use?
I can imagine a number of reasons:
- Slip in the rotary module - in this case the vertical lines on one side would have a dark edge and I’d guess that the lines are not perfectly straight
- Software bug - rounding errors may have the angular movement miscalculated, so that ever once in a while two stepper steps happen without the lase taking this properly into account - what speaks against this is that this then should be uniform across the job. Solution would be to use alternative Software, e.g. Lightburn.
- Unhappy conicidence between PWM frequency and movement - the 1.6 W and the 10W laser only operate with a PWM frequency of ~100 Hz, and this can - with fast movements - cause gaps. Solution would be to slightly change engraving speed or engrave with 100% power (PWM becomes irrelevant) and increase speed accordingly. This has limits, as the rotary can only go at 45°/s max.
- Other software bug - if you do a GCode preview, are the gaps visible there also?
- The gaps are in the shape - if you zoom in to the image you use: Are the gaps there?
- The image you use is a rasterized b/w grayscale image - in this case make sure you use the b/w setup in Luban, otherwise the greyscale algorithm of Luban may overlay with the greyscale raster of the image. I admit that this is a bit far fetched…
Thank you for the quick response. I’ll post photos directly…
10watt and SVG files. It has happened on a few other rotary projects but others turn out great… Attached 2 pics. 1st is after extensive cleaning using GooGone and magic eraser. 2nd is after reducing speed from 1000/min to 800 and increase of power from 40 t0 45%. Very faint but lines still present…
I’m not really seeing what the problem is in those pics, they look pretty good. Have you tried adjusting the Fill Interval for a higher “resolution” burn?
Alternatively, adjust the line direction to Vertical, so that any lines go in the same direction as the finish already on the metal.
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Same here - I have difficulties understanding your issue, but after all you said that you already post-processed both results, so perhaps it is less obvious? The fist picture shows some pattern on the lasered parts - to me it looks like residue from the paint treatment or metal preparation - but I have difficulties really telling from the photo. I you happen to have a new, fresh example, please post another photo before you apply any next steps to the job!
Sorry the pics didn’t express what I am seeing better. Tried a higher dpi but didn’t help. At first I thought maybe it was a flaw in the metal the manufacturer used but the lines are consistent on every piece and exactly in the same place and just the left side As far as changing the line direction, I have tried to get it to burn vertically but it doesn’t change no matter the choice. Has been that way since I started using the rotary… Flashed with firmware several times but to no avail.
Off the wall thought… Does the diameter settings on project setup have a possible conflict with being an odd number and giving the gcode fits?
Can you perhaps mark/point out the places on the photo with an arrow or circle?
Odd values should not be a problem.
A problem could be that the rotary has a max angular speed of 45°/s - which, depending on the diameter of the workpiece may translate to very different linear speeds. see This thread: Bug: Luban allows faster speeds than the rotary module can accept for more information.
Can’t see anything wrong.
Are you referring to the steel surface?
It seems all normal to me, it’s like a steel surface could be if it’s not polished.
Talking about the vertical darker bands of equal spacing that only show up on the left side of a project and with the same exact placement on 18 straight burns of same project and others as well…
If it’s not a result of the process of the metal itself, then it looks like it’s caused by an inconsistent rotation speed caused by lumpy bearings, or the drive gear (if there is one) being non-constant-velocity.
Can you share the right side without the vertical lines?
Is the Rotary module rotating equal when you laser this area or is it rotating X degrees, stopping, continuing for X degrees?
That’s the only explanation that comes to my mind - there are two threads in the forum I’m aware of that show faulty rotary module speed:
I guess the first suggestion by Snapmaker support is to check tightness of the belt, which should not be too tight, and not to loose (FWIW). The first linked thread shows how to disassemble completely, because that user hat loosened grub screws that caused slip.