Concentric First Layer
I can have problems with first layer (who doesnt'). I'm printing a very large print on a Prusa XL in PetG that has a bunch of little footprints on the bed (islands). It seems like the 2 edge outlines of these feet come out nice and the issue can be when the zig zag happens.
I was curious if it is possible to do a concentric first layer where each individual part touching the bed gets fully completed before moving on to the next, across the board, perhaps back to front, left to right. Is this possible? Is this idea decent or does it not matter at all. It could be that if the first layer is going to peal back or curl up on the normal print that it would also do it on concentric. It just seems like sometimes when I pull a jacked up first layer off the bed the trace is in nicer condition than the inside.
I attached an image. you can see the bad area - but when it did the outline it was perfect. It does a great job bottom left to upper right and then when it gets there it looks like that. I can't sit and watch the printers every move, but I have to assume that zig zag just starts tearing everything apart.
Looking for advice there.
RE: Concentric First Layer
I didn't see any mention of bed leveling, so I'll ask -- have you used a bed visualizer to see if that corner is significantly out of level? Not sure the best approach for the XL specifically, but I'm sure you can find some YT videos/blogs giving tips on leveling it.
The only other suggestion I can give: Clean the crap out of the sheet with iso alcohol and if that doesn't fix it, apply some glue stick.
Another suggestion that may help troubleshoot the problem faster is to cut the model so it's only printing in that corner so you can iterate on it a couple of times to see if you've fixed the problem without having to print a full first layer.
Hope you get it figured out. Those kinds of issues are frustrating.
RE:
I printed the X-Mirror flip of this perfectly, and then it was failing.
I have been iso cleaning the sheet like crazy. Its helped but still did that print in picture (which Is the latest and best)
The only difference I can think of between the first (right side) print vs this new (mirror flipped in Slicer for Left Side) is that the Hatchbox PETG came out of a bag with silica in it for the first print and then the second is like 18 hours later sitting on the spool.
I have never heard of Bed Visualizer for out of level! Do tell. What is that?
I have never used gluesticks! Just get typical Elmers sticks? White or blue? And lightly skim it in that corner?
I was very much wiping and cleaning sheet. Underneath and on top etc...
One thing of note is the table it is on isn't too stable. But that usually isn't an issue. The table vibrates on small back and forth motions. I need to get a solid nice table for it but its so big I need to figure that out. I'd like enough room to easily run directly out of filament dryers and have a lot of tools and things around.
Good idea on isolating to that corner. The print before was bad all down the left side. I can try getting it solid in that corner.
I could also try a raft. This is one of those prints where i don't care how thick the base layer is. I wonder if its best to make the first layer thick or print on a raft.
Rafts can be kinda annoying to deal with though.
The concentric first layer is still a curiosity. Even if its slow, may be it would work out especially if it did each island fully before moving to the next.
RE: Concentric First Layer
Brand newly opened Prusament PETG shown in photo
I put the Hatchbox PETG in a dryer hoping that will help. I hear so much about drying filament.
The issue with Prusament is crazy shipping and handling. If that was smoother I would probably use it a lot.
RE: Concentric First Layer
For glue sticks, white/blue/brand doesn't really matter. It's just something to add a little extra adhesion to that corner. If you don't have a glue stick, you could also try hair spray as an alternative. Just let it dry before printing on it. Keep in mind, it may make the print stick MUCH stronger to the sheet when done printing if you're using PETG. Try to remove the print while the bed is still hot (or warm the bed back up again if you don't get to it until it has already cooled down).
For the bed visualizer, I use this plugin for octoprint. It's very useful for seeing how bad your bed is warped and in which corners.
I don't have an XL, so not sure how it's put together, but for the Mini, you can use rubber o-rings between the frame and the bed to tighten certain corners more than others in order to make it as level as possible. I've heard of some people using single lines of tape on low corners to prop it up. It really varies per printer, but I'm sure there are topics specific to the XL. Most printers automatically compensate for slight variations, but if it's WAY off (specifically lower than the rest of the bed), it could affect the print.
You could also try doing the live adjust Z calibration and bring it down a bit if it's too high.
Prusament is good filament, but you shouldn't have to use that to get results. I print on just about anything, and I rarely adjust the profile in the slicer. Prusa has profiles for Hatchbox PETG, so I would use those since they're available, but I don't think that's your problem.
Drying out the filament is definitely a good idea. Moisture causes all sorts of problems. I once printed the same model with filament that was dry and then after it had been sitting out for 24 hours, and the difference was astounding. I was a believer after that and I dry box all of my filament now. There are DIY solutions using sterilite containers with foam gaskets that work well and are much cheaper than buying an actual dry box. This is the one I use, and it has served me well.
RE: Concentric First Layer
Another idea: Until you get a solid table, you can try putting the printer on rubber feet or foam if it's not already. If you're in the US, Harbor Freight has foam knee pads for $3-4 that help dampen vibrations. I don't think the vibrations are your problem either, but it couldn't hurt if nothing else works.
Another thought -- are you using an enclosure? If so, you might remove it or change the air flow in case that corner is getting a weird wind pattern from the fans.
If you look closely at the failure pattern ... those are fingerprints.
@willdeed was right in his first post - rigorous cleaning should address this issue.
Clean the sheet with dishwashing detergent (Dawn/Fairy) and plenty of HOT water, rinse well and pat dry with a fresh paper towel. Handle by the edges only.
Suggested routine:
Clean with IPA between prints.
At the first hint of a problem, use dishwashing detergent (Dawn/Fairy) and HOT water.
If this is not enough rub neat dishwashing detergent into the sheet, wait a few minutes then rinse clean with VERY HOT water.
All this assumes ordinary fingerprints, perhaps including stray sugars or light lubricants but if you are handling aerosols, paints, sprayers or similar in the same workshop then there might be other cleaning agents required. The sheet must be clean.
I put the Hatchbox PETG in a dryer hoping that will help. I hear so much about drying filament.
Wise: It's not the cause of this particular issue but a print this big will be affected noticeably if your air is damp and you don't dry before you start.
You shouldn't need gluestick with the satin and textured build-sheets but if you use PETG with a smooth sheet a couple of lines of PVA glue diluted and wiped over the print sheet with a wet paper towel will prevent it sticking too tightly.
Cheerio,