I’m using a P1S. When I print my own model, I’ve tried slowing things down considerably and have also tried fully disabling aux fan. I think slowing down does help but not that much.
I’m also using bambu PLA Basic in both cases, including different ones. I’ve also tried PLA matte which I think may have been worse.
I’m not sure what the defect is called to even research it but it’s been driving me crazy so I’d appreciate some help.
Edit: I’ve tried the belt tightening procedure as well. What’s strange is that it only happens in a specific range of the sphere - in the part that should be the easiest to print I would think.
In technical parlance, this phenomenon where you’re seeing drooping is called Gravity. It is that very egalitarian force that exerts itself indiscriminately on all mass upon the surface of a planetary body, mercilessly sabotaging your dreams of perfectly spherical prints. Truly, a tragic consequence of living outside a vacuum chamber.
Now, switching gears to plain English: when you look at this page, what do you see?
I’ll tell you what I see — just another flashy click-bait model, probably a computer render (like this one), or at best a cherry-picked photo showing only the best angle. But hey, the creator got you to waste some filament and hours of hope, right? Happens to the best of us, trust me. Fool me once… well… you know the rest.
Bottom line: you can’t print upside-down sections without droop unless you use supports, and you can’t use supports without leaving scars. Your print is actually really good — you should be proud. I don’t think you can expect much more. Want better? Sure, just wait for Jeff Bezos to sell Blue Origin flights where you can print your basketball lamp in zero-G — just make sure it finishes in under 11 minutes though!
I have some "fun’ with P1S and I gotta ask - is the “droopy” part on the opposite side of the aux fan? If so and my theory is correct, then that part of the print doesn’t get adequate cooling from that side…
I’ve tried this with my own model that doesn’t have that ridge, but this is actually happening on the side of the model so the part LEAST affected by gravity. It’s literally in the place with the least overhang of any part of this print as far as I can tell.
I.e., that picture is sideways; I’m showing the side of the print, not the top. So it normalizes shortly after hitting the easiest part of the print for some reason.
Well if that’s not the side facing the earth, it would help to understand the original model orientation as it sat in the slicer window. This will tell us a lot about how the model and the filament interacted. A screengrab of both the prepare and preview window right before it was sent for print is a key piece of data that would help us help you in a possible diagnosis.
Having said that. Has the orange filament been dried and please don’t tell me the AMS says humidity is zero because that and $10 will get you a cup of coffee at your local coffee shop but not much more.
Troubleshooting 101: Weigh the filament, dry the filament, weigh it again to look for moisture loss. Why is this necessary? Because if you don’t weigh it before and after drying, you can’t know if the filament was wet before you placed it in the dryer and therefore you have no idea if its dry or if moisture was any impact to begin with.
Thanks for the follow up! I sent this particular print from my phone so no prepare/preview but I slapped it back on the printer for a photoshoot of the orientation
Filament is dry, and defect spans white as well. I didn’t do the weighing but I use a dehydrator and then keep my AMS jam packed with silica.
As an aside, it’s also around 20% ambient in winter here because of heating so it’s quite nice for printing, although summer is quite humid unfortunately.
At this point I might be looking at fan temps. Given the size and shape of the object, if I understand you correctly, that is on the right side which would be away from the auxiliary fan. If the fan is engaging during print, there is a very high degree of likelihood that what you’re seeing is uneven cooling. So if that’s true, then here is the tricky part. You’ll want to turn off the fan and experiment with different settings.
Personally, I would not choose this model as it’s a lot of filament. However, you may be able to recreate the conditions well enough by creating a cylinder primitive about the same diameter as that ball. Then color it using the paint tool at around the same height. Then print it using spiral vase mode. This will use a lot less filament. After that, it comes down to varying fan speeds, keeping the door and lid open or closed in order to find the right temp.
Now if you really want to go down this rabbit hole, here’s what I do. Get yourself a couple of thermometers with external probes. Why probes? they can be placed more accurately. These are just some example of reptile cage hygrometer/thermometers that I use. They are cheap enough where you can by 3 or 4 and not even add up to one spool of filament.
Place the probes around the printers interior keeping mindful to keep the cables out of the way of the moving toolhead gantry. Then when you print your object, monitor the temp differences.
Ha! If I’m going to get that crazy, I have a few BMP/E280s I could wire up to an ESP32 and make the whole thing real smart although I think the homeassistant control is dead with the new security updates. Still the data could be useful. I’ve run prints without the AUX fan at all, so it would have to be exhaust fan causing uneven cooling, but that’s seems a bit dramatic of a reaction. I think I need to measure the height of the intake for the exhaust fan since those marks only show up at the mid point of the sphere.
Then again, if the chamber fan was the culprit, we would expect the marks to show a bias towards the back or at least away from front of the model … but that’s not the case.
I could also try a print where I set the sphere in the corner to see how that changes things.
This is exactly the kind of interaction that keeps me here. It’s one thing when someone has a challenge and comes here for a quick question but its a thing of beauty when folks jump in and add to the investigative body of knowledge to find out exactly how the tech really behaves and not just what is in the wiki or what some YouTuber was able to reproduce “once for the camera”.
