This is my most challenging print to date. The cast iron fence design is fully 3D (with the top rail the widest component on both sides that was extremely scaled down to the point that thickness was 1mm and the first print produced pure spaghetti.
After adjusting the thickness to allow full 3d production and enabling support (using Bambu support filament) the slicer never actually used the support because it cannot adhere properly to the bed.
So remembering an early screw-up where I discovered the utter incompatibility of PLA and PETG I eventually came up with the solution of a using PETG as the support as well as an additional “pad” layer to ensure good adhesion.
Through trial and error and the bizarre contradiction of Google ARTIFICIAL intelligence that replies in the negative to both “Does PLA have a higher thermal expansion coefficient than PETG” compared to the exact same question save the switch of “PLA” and “PETG” I’ve achieved the best release of the incredibly delicate and fully 3D decorations between the vertical elements by letting it cool naturally on the plate followed by about 10 minutes in the coldest part of the freezer as it [seems] that the PLA will contract slightly more than the PETG thus aiding release.
Here’s the pic of my best yet removal with at least 95% of the tiny elements intact.
I also discovered the GREAT importance of REGULAR running of the FULL auto-level function!!!
Once I enabled the pad I noticed that the initial layers of this ostensibly perfectly flat yet maximum length (diagonally) print did not lay down evenly. As the print progressed I realized it was because of the “quick level” function detecting inconsistencies that the support structure attempted to mask. In this instance it was as if the top-right and lower-left corners of the plate “dropped off” by two layers. So, I ran the FULL auto-level function and repeated the exact same print (after yet another scrupulous cleaning over bed and build plate) to find it built as a perfectly flat object. (I’ll add this to a separate–and shorter–topic.)
No, I’m still using a 0.4mm. You are probably right. Thanks! I’ve avoided the tiny nozzle to also avoid the wildly increased print time and [supposed] problems with clogging.
I’m fast approaching 1,000 hours of operation time in this my second A-1 after the first self-destructed due to loose assembly screws throughout the entire machine. The replacement too was utterly filled with loose–and I mean LOOSE–screws throughout as well!
Once I hit about 1,000 hours I intend to go through the entire machine again looking for loose screws to see if this is a serious problem that occurs during normal operation. I’ll order a 0.2 mm hardened nozzle and another 0.4 mm for the inevitable time when the original fails and try a swap on that print.
I think with standard filament like PLA and PETG the risk of clogging is not a big issue. In my experience, the stock filament profiles for the 0,2mm nozzle are very conservative regarding max flow at something around 3mm³/s. When I tested the maximum flow with test in Orca, i reached more than 10 mm³/s if I remember correctly. I think higher speeds even reduce the risk of clogs and the print duration doesn’t hurt that bad anymore. Another user had the same thoughts and was happy with a much higher flow.
I’m now far more comfortable using a 0.2 mm nozzle. I also recently experimented with the general speed settings (quiet, normal, sport and ludicrous) to find to my great surprise that ludicrous speed will produce a plate nearly full of fairly good-sized “identical” objects that vary only in gross height when it fails at normal speed. Of course it does require perfect cleaning of the plate after each and every print as well as the lightest spray of hairspray which must of course be COMPLETELY scrubbed away during cleaning.
My installation that finds the A1 and AMS on a 1" thick x 2’ square rough finished granite slab which itself rests on a layer of new microfiber toweling is, I believe, what makes such fast printing practical. As the objects grow above 3-4 cm or so I do slow down the speed to “sport” and use “normal” (and less than a plate full) when the same objects are scaled such that the height goes about 18-20 cm. Inertia causes the higher mass and height ones to come loose from the plate so I can only print one or two at a time.
That really sounds weird. Can you share screenshots of such a plate in the slicer? In which way does it fail?
I almost never use the faster speed modes, mainly because i have optimized max volumetric flow, so it seems to make little sense to me, printing faster than that. I prefer to instead increase speeds etc in the slicer. But I don’t know if the speed modes change more than that.
Will share pics should it happen again. At “normal” speed using default settings for the specific filament (PLA+ in this case) I seemed to get perfect adhesion with a large number of identical objects but the failures would occur when the pieces were about 1/2 cm thick with a 5 layer bottom shell, three wall loops and 30% triangular infill. Said failure being one of the items literally just coming loose during movement.
I had a similar problem with PETG objects which ordinarily adhere very well to find them being literally pulled over during the “blob detection” events following the initial one at about layer 3. Merely disabling the feature allowed me to put many more of the same object onto the plate for for an overnight print with essentially every chance of success.
I always use the “dynamic flow compensation” feature at the beginning of each print as many of the objects I print (functional support brackets and other similar pieces USING PETG are effectively solid with 100% infill or simply too thin/delicate to even have space for infill. I’ve not altered the speed setting for PETG objects as I get utterly perfect “solid” objects that interlock with “teeth” and other closely fitting means which tells me that the flow rate has been truly idealized.
I have however found it essentially impossible to print more than one detailed, fair sized “solid” PETG object at a time due to layer adhesion problems. I’ve also given up on two-color PETG objects with more than a few carefully spaced color changes and still without a wipe tower due to the very same problem of layer adhesion as the object grows. The one and only time I attempted to print two fair-sized “solid” PETG objects with frequent color changes produced objects that not only snapped apart easily but I could literally unwind meters worth of shell filament on both sides of the break.
Should I ever decide to upgrade 3d printers it will ONLY be to one that features switching tool head technology as I detest both the huge amount of waste “poop” and very frequent misprints when making multi-color objects of any more than a few mm thin.
That sounds like something has gone very wrong and should not happen.
I fully agree on the amount of poop, but i haven’t seen many failed multicolor prints yet. Especially not resulting in prints detaching.
I generally avoid crossing infill patterns, which triangular is too. They increase the chance of knocking prints over, but usually at higher layers and mainly with PETG. For that reason, I only use crosshatch and sometimes gyroid. But I doubt that this is related to your problem.
How do you clean the plate?
And have you enabled automatic bed levelling at the start of a print?
Cleaning: Wash twice with Dawn “Power Wash” using a dedicated scrubber. Cold water rinses. Thorough dry. Then a very light coat of hairspray, especially for delicate PLA objects. If using hairspray I either fully wash after every print or more the object to another location on the build plate and print an additional copy or two before cleaning.
Quick bed leveling before every print and dynamic flow compensation except when immediately making an identical print using the same roll. After watching some particularly delicate objects being constructed on a “pad” support I’ve begun to run the full bed leveling procedure weekly.
