I don’t know if this is a hardware or software issue.
Sculpfun S10. LightBurn 1.5.06. Toshiba laptop, Windows 10.
Sometimes the first shape I cut in a job doesn’t cut. The laser head tracks the outline but the laser doesn’t fire. When there are multiple passes it tracks the shape multiple times but no laser output. The next shape is OK, and all subsequent shapes cut as expected. If I redo the entire job, the fault doesn’t re-occur.
This is an occasional fault, maybe one in ten jobs. It doesn’t happen often enough to fault find by elimination.
My options at the moment are add a small shape in a waste area of the job and put it on the first layer, or go back and redo the first shape.
Odd issue, hard to track down. I don’t think it’s a hardware issue, if it’s object related. The only hardware issue I can think of is a weak USB connection, you could try a different cable. And if it is in some specific area of the workspace, the laser cable could be a reason. But it doesn’t sound like this.
So it seems it’s a LB / configuration issue. But if it’s that random, it’s really hard to find…
I doubt it is a laser cable. The missing shape is always near the origin (lower, left) because that’s how I frame up most jobs.
LightBurn is set to cut inner shapes first. The outer shapes cut correctly later. The first cut might have a perimeter of a few millimetres or hundreds of millimetres, but the laser doesn’t fire. The second shape, on the same layer, in the same area, gets cut reliably.
I’ve tried three different USB cables. All with metal braid screening and routed well away from any other cables.
One other bit of information that might be relevant: I always cut first, then engrave. The air assist is automatic, controlled from LightBurn. Maybe there is voltage dip when the air pump cuts in.
Yes, could be a reason, though usually the laser fully stops if there is a voltage drop (Sculpfun machines are a little bit picky about this, a common issue). You could try to use a stronger power supply or change the power lines for the laser and AA.
Just for grins you might try changing the sequence from cut then engrave to engrave then cut on the first object and see if it makes any difference. Curious why you cut then engrave, I find when I do that the material may drop slightly and then the laser is no longer at the same focal length.
I have an S10 as well and have never had this issue, but if you are running the same job and sometimes it works and other times it fails or are you running different jobs and it is just randomly failing? Random failures are really hard to track down. If a job fails you might save the file and then when it runs correctly save it again and use NotePad++ or similar program and compare the two files to see if there was any GCode changes detected. Kinda like have you car fail so you take it to the dealer and it works fine, you get it back home and the problem pops back up. Annoying to say the least.
It’s random failures and different jobs. It might only be on the first job of a session after the PC has been asleep. It is so random I haven’t got a firm pattern of failure.
I was an instrument and control technician in the power industry. We logged random faults like this “TSFs” or “Technician Sensitive Faults”. I held the record for taking fifteen years to track down a random alarm initiation.
I’m usually working with budget 3mm pine ply. It can gum up the lens pretty badly. Early on I had a lot of failures due to gummy soot from a large engraves partly blocking the tip of the air nozzle. I had fewer problems cutting first.
I run in the Sculpfun enclosure and changed the stock fan out for a 5.25" PC fan and it helps remove the airborne debris and smoke much faster. Run with air-assist on at about 50% speed most of the time.