Hi, all! I've just spent a couple of hours reading through some very informative posts relating to a problem I'm having with my laser cutter, and I want to start by thanking you all for the wealth of information that is here!
I found lots of posts that might relate to my situation, but I wanted to post and see if anyone had any further insight.
I have a home-built (Buildlog 2.0) laser cutter that I've been using in production for over a year. I'm very used to how it normally operates, so when things started going awry last week, I immediately checked all the usual suspects.
Some specs that might help:
- 40w tube (we buy from Light Object)
- Water chiller inline (it's a lab-grade chiller, and water is kept just under 60 degrees F)
- No protection switches for water flow or door closure (I do have an indicator that shows if water is running or not and check it very, very often, as well as continually monitoring water temperature while working)
- The cutter is run anywhere from 5 to 18 hours in a day and has done this for over a year
- Mostly cut 1/16" cork and wood, sometimes 1/8" acrylic
I started having two concurrent problems, and I'll start with the most troubling one- power loss during a cut. I've seen this happen a few times before- we got into a couple of bad tubes last fall, so I know all the signs of a failing one. Cuts would start out great, and by the bottom of the sheet (anywhere from 12 to 25 minutes later), the beam would no longer cut through the material. The tube was rather new- just installed September 1st and had a few hundred hours on it (we run hard here!)- so I was surprised that it would start to fail so quickly. We did investigate and replace the high-voltage power supply, but it didn't make a difference. After verifying alignment (again- so many times since last week!) we pulled the tube and replaced it with a new one that we just got in about 6 weeks ago (we always keep a spare on the shelf). Imagine my surprise when the issue continued!
At this point, with a new tube and new power supply in place, we wondered if the controller (an AWC-608) was having trouble, so we swapped in our spare of it (yes, we keep gobs of spares here). Still no fix. Not only that, but I discovered that now the laser would sometimes emit a high-pitched whine/squeal when first trying to cut at full power, especially if I'd been running at PPI for a while. I actually managed to catch that failure on video and uploaded it to YouTube.
Since discovering that, I've put the original HVPS power supply back in, and the whine/squeal is still happening. I don't see any arcing around any of the connections or wiring when running with the lights out. I did redo all of the high-voltage connections just this afternoon for good measure.
At this point, I'm wondering if I either a) have had two bad tubes in a row (it has happened before) or b) have had two bad high-voltage power supplies in a row. Or is there an option c) that I haven't thought of yet? At this point we've replaced every major component in the cutter with the exception of the low-voltage supply. I do have an extra one of those, but it just seems so unlikely that it's the culprit.
Any help or ideas would be greatly appreciated!