Re: Inconsistent engraving problem ?
Posted: Thu Dec 20, 2012 9:29 pm
cvoinescu wrote:If the coolant pump is on only while the laser is on, maybe there are bubbles or dirt in the coolant, which randomly disperse some of the laser's power, until the coolant circulates a little and flushes them out, which is when the situation improves.
My pump is running anytime there is power to the machine, not just during lazing, so it is not that, I believe.
If it were mechanical - related to dirt, etc, it would vary with physical position of material on the bed. It does not seem to. Though my rails are often gritted up from jobs, I have repeatedly cleaned and tested with no real change.
Remember my comment about where the banding begins. No matter how many different thought paths I go down, I always come back to the fact that the problems are more predominant when there is a change in the on/offs of scan lines. I have seen it in photos where the facial features cause the lines to begin or end. In nearly every case, I can see a correlation between the features of any image and where the banding is or is not. There is always noticeable start point that is at the same y level as the image feature change, like bottom of a nose or edge of a running stream or edge of wings, etc.