I’m trying to get back into 3d pruning after a long hiatus.
I found my old Anycubic Chiron, and thought I’d give it a go. Smaller prints seem fine. But anything longer than an hour. Come off like this. I say that what I mean is I excitedly take the multi hour print off the bed in excitement and for get to look at how it is.
The two longer prints definitely were at least in part still adhered to the print bed despite it being cold.
My next plan is to set a print away and check on it every hour or so and see if one side of the print has warped mid print (so far I’ve been printing before I go to bed, and only watching the initial couple of layers).
My guess it that the (pla+) filament is warping mid print… Its old I’ll admit. But was stored in an airtight container with silica packs, and I dried it out before using. But any of your thoughts would be greatly appreciated!
My guess is it’s warping from thermal contraction as it cools. PLA is easier to print with than, say, ABS, because it doesn’t contract as it cools quite as much, but it still contracts some, and each successive layer, it’s like layering on rubber bands, until it pulls off.
there’s several things that can help it. The first is to use a heated bed. (you want to set it for moderately below the glass transition temperature PLA+ is typically around 50-60 in actual temp. I’d suggest measuring the actual surface temp with an IR thermometer… if it’s glossy, take a sheet of paper or a single-layer bed leveling test print and place it on top.
If you’re already using a heated bed and the temp checks out, the next option is to print a brim up around the part. this increases the surface area. Additionally you can increase the skirt height to create a wall that traps air and keeps the part warmish (slightly lower than bed temp, typically.) You don’t need to go all the way up, even an inch will help.
Going a step further, you can set up a box over the printer as a make shift enclosure. Or, if you’re looking for a more permanent solution, I like using rigid insulation foam- you can get it from your big box hardware store for pretty cheap. 1/4" 1/2" sizes are easy to work with and you can use PVA glue to hold it together, or most epoxies. (hot glue if you’re careful, but it’ll melt if you put too much on.) for just a one-off project, you can cut it using a box cutter, but if you use it a lot, there’s hot knife cutters (or wire cutters,) that work wonders… but that’s another topic.
Thanks for the advice.
The heated bed was set to 70, however I’ve realised it’s actually only for the initial layer where it drops to 60.
Do you think I should try to consistent 60 or 70?
I do have an IR thermometer so I will give it a thorough probe…
As for an enclosure… This is something I remember planning when I initially got the machine years ago. Unfortunately one of the big selling points of the any cubic chiron was the enormous build plate! This means building of an enclosure for it eats up quite a bit of space 😂 It’s currently situated underneath a desk with three of the four sides covered, but I shall make a curtain to cover the front.
N.b. I can’t ever recall using any significant amount of the enormous build plate… So when I look to buy a new printer, I’ll definitely go with something a lot smaller, with an enclosure.
its not uncommon to start high and come down a bit. PLA+ typically has it’s glass transition right around there, and you do not want to be above that.
check the actual surface temperature, if you can, since most beds, the surface will be cooler than what the probe under it is saying, but typically you want 55ish for printing temp.
another way you can check is to just set some scrap plastic of the same filament on it. If it goes rubbery and pliant, its too high. the tricky thing about glass transition is it’s not a single point, it’s more of a small range, where, approaching it, it starts getting noticeably softer until it stops changing as much.