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View Full Version : banding... the tube, or not the tube....



Scott Weinstein
09-11-2012, 11:23 AM
Hello All,

I run a Vy-tek 60w laser. Over the last 3 years I have encountered plenty of banding issues mostly resulting in resolution vs material and of course dirty or misaligned optics, which can easily be resolved through plenty of R&D. This new banding issue has me quite stumped so I turn to the Sawmill community for suggestions.

I am running a basic solid fill bmp and am getting horizontal banding across my entire image in random sections. It is as if the power of the laser is working like a roller coaster, it peaks power, then it drops power in no even order. The photo below looks as if it is a repetitive pattern but on other parts of the image the banding spacing is different and random, like 1/2 inch dark, 1/4 inch light, 3/4 inch dark, 1/8 inch light...etc.

I have ran multiple files, lowered DPI's, tried gray-scale BMP's, changed black fill to gray, changed speeds, changed powers, tighten belts, re-aligned and cleaned lenses, re-booted machine, hardwired my machine rather than running it on a network, tried different materials, and nothing seems to correct these banding issues. I am leaning towards the tube beginning to fade out however after taking power readings following hour runs the power appears to stay constant.

We have had the machine since 07', and it sits in a warehouse that is not exactly spotless. Never have we had to change the tube.

So to those whom have had to replaced your laser tube, do these issues and photo suggest that this thing may be on its last leg?

I appreciate any help and guidance!
240956

Lee DeRaud
09-11-2012, 12:29 PM
I can't visualize any failure mechanism in the tube itself that would be that consistent from one sweep to the next. (Hint: the tube has no way of 'knowing' where the beam is hitting.)

Given that there are multiple causes for banding (DPI mismatch, motion-system glitches), it's quite possible that you have more than one thing happening and the multiple banding at different intervals adds up to the irregular pattern you're seeing.

Russell Holder
09-13-2012, 7:28 PM
Try rotating your image 90 degrees. What does that do to the banding. My banding just appeared when I switched my image from one direction to the other. I have a 35 watt Vy-tek. I have know idea what is going on with mine. I am getting ready to start at the basics and see what makes it better.