On a few occasions, I forgot to remove the purge line at the front edge of the build plate after a print. I usually realize this with horror as the nozzle is raking across the old purge line at the start of the next print.
Why doesn’t the printer firmware use the X1C LIDAR to look for a leftover purge line? It seems like Bambu Lab could squeeze in a quick check for a leftover purge line before laying down a new one.
Or is there some option to do that already, and I just haven’t found it?
It doesn’t look. It would take more time. There are purge lines at the back, too. And if you forgot those purge lines, what else did you forget? If the machine was checking for left over filament on the plate, it’d really need to check the whole plate.
FYI - The purge line at the back was removed from Studio a couple releases ago.
(Circa November 2024)
Ah. I’m way back on FW and Studio revisions. Stopped updating when the security changes were made. Machine does everything I want it to, and it does those things just fine so I haven’t had a reason to update.
The few seconds would be inconsequential compared to the benefit. It might even be possible to do the check while the printer is waiting for something to heat up or cool down, adding no time at all.
That’s a False Dilemma fallacy in which you posit that the LIDAR must either check the entire build plate or not check any of it. There’s nothing wrong with the LIDAR spending a few seconds checking for a common mistake, while not turning it into a five-minute scan of the entire build plate looking for uncommon mistakes.
Many people who never left anything else on their build plate have left purge lines. I speak from experience when I say that it’s pretty easy to visually miss a white filament purge line that’s imprinted almost exactly atop a white line silkscreened onto the front edge of this build plate:
Or, you could just remove it when you remove your print. Or when you check on your print.
Not knocking you but while you may have this problem and you may not be alone, it’s not a high profile or high priority problem. I wouldn’t hold my breath for a resolution.
IMO if it’s a mistake you’re making frequently, you should consider putting together a checklist of things to do when a print ends so you don’t forget. It’s not a common mistake at all for me. Not sure I can remember ever doing it.
If the plate comes off the printer to remove something that’s already been printed, it doesn’t go back on the printer until everything is removed. Simple rule, if followed, eliminates the need for added complexity for the FW and software.
I suspect everyone has left a purge line in place a time or two. Sometimes black on black textured PEI can be hard to see. It is not an ideal situation, but I’ve never had it cause an actual problem.
I don’t expect a machine to anticipate all the potential mistakes I can make because no matter how hard to you try to make a procedure foolproof there will always be a more creative fool.
Same here, I’ve accidently and sometimes even purposely printed over the purge lines 2 to 3 times and never had an issue. Heck it can even make them easier to peel up. lol
What you describe is my standard operating procedure. But I’m imperfect, and a few times a year, I screw up and overprint an existing purge line.
It’s very rare that I make that mistake.
If you had perfect memory, you’d be sure whether you could remember. 
I have never put a plate back onto a printer with anything on it.
I don’t remove the plate if the printed object(s) will easily release with the plate in place. That keeps my finger oils off the plate and reduces potential handling-related mishaps.
Detection of an existing purge line should not be not something terribly complex for a LIDAR that is up to the task of first layer quality inpections. It’s likely to be largely code reuse. Besides, the software/firmware is already chock full of safety checks for common mistakes, as it should be.
Thanks! That makes me feel somewhat less paranoid.
You are not alone. I did it at least one time as I can remember. When I realized that, the print sequence already started so I left it be, knowing that the printer is designed to print over calibration/purge lines. The print came out fine.
The check list idea is a very good idea, that is why they do them in airplanes!
You do checklists in airplanes so that people don’t die. This isn’t a life or death situation.
This thread was just a feature request for something that would occasionally warn X1C customers with something like: “Purge line detected on build plate. Please remove and hit the continue button.”
Hi Miss Sissy. Your issue with the purge line is correct, it should be solved. So please ignore the silly people who say it isn’t a problem - and it’s your fault. It;s just typical of the comments these days from people, some with a superior technical knowledge elsewhere who just want appear superior - but they are not really. Happens on many sites these days,
LIDAR is not required to do a visual scan of the build plate; a simple A:B photographic comparison would identify anything left anywhere on the plate. A better/ better aimed cam would help but should be doable with the existing unit.
