Flashforge ASA issues
So I have some Flashforge burnt titanium ASA filament for a project. When I first tried to print with this filament, it gives me a strange issue that I have not seen on any other filament, or any other ASA. my printer was converted from MK4 to MK4s to now a Core 1. I think I printed this filament on the MK4 but had issues that I don't exactly remember, but it could have been this issue. It looks like a weird scaly or bubbly texture that appears on the benchy hull line the most, but if you haven't tuned your settings specifically to counter this issue, it appears all over the hull. I need an answer different from "calibrate your filament" that is like the answers seen on similar posts. I have been "calibrating" this filament for weeks now. Various settings make this issue worse or better when combined. for example, decreasing the print speed helps, but only in a specific combination with temperature and extrusion multiplier, otherwise it gets worse. the best setting I have tested is increased print speed with a lot of under extrusion (0.9, when the calibrated extrusion multiplier is supposed to be around 1.1224), noticeable because there are gaps in perimeter lines . Is this an issue with the flow calibration cube that I have just ran into with this specific ASA? It appears that increased temperatures and higher fan speed helps in a specific combination, although if you get the settings wrong, the side on the fan is a lot worse. The only answer I have managed to see other than "calibrate your filament" is over extrusion, although the calibration cube tells me otherwise. Note that changing layer height to 0.2 from 0.1 makes it somewhat better, and the horrible floor of the benchys appeared recently after changing a couple of settings, although it might have something to do with it. the floor was fine before, but I am still experiencing the scaly hull. Any help or ideas would be appreciated.
RE: Flashforge ASA issues
Great to find a fellow sufferer from the dreaded FlashForge Burnt Titanium ASA! Pic below is the same print printed fresh from the bag and a couple of days later.
Like you I've tried a lot of tweaks, but interestingly enough I spotted a couple of Reddit posts where users of this particular colour of filament (ASA and PLA) have been complaining about it - basically when it prints properly it's sublime, but otherwise it's a total pain in the seat!
Most suggestions I've seen about the ASA (in particular) is that the additives that make it that cool multiphasic colour also make it about 1000x more hygroscopic, so the "crowd wisdom" was that this needs a 60-70C drying for about 6-8 hours before you even start thinking about using it. One guy also suggested a 10 hour dry and then print from the dryer while it's still drying.
So that's what I'm going to try next - those models take about 4 1/2 hours, so I'm going to dial up a 9 hour drying programme on my Eibos dryer on its ASA program then do a feed-from-dryer print after about 5 hours.
PS not sure if it's my C1 going out of tune again, but I'm seeing a lot of nozzle clean errors with this filament after the first print. It's been sitting out for a couple of days, so maybe the Redditors are correct in saying that it's now H2O saturated?
Hope this helps, I'll keep my fingers crossed for your tweaking. Failing that, I'll come back here if the drying does sort this out...
RE: Flashforge ASA issues
Well, I did my experiment, and here's the results below, from right to left that's fresh-out-of-the-box; sat-out-for-a-few-days; and dried.
The walls of the freshly-opened and dried are smooth, as is the roof. Plus the sat-out-for-a-few-days is actually a different colour and the walls and roof are rough enough to use as a nail file... 😉
So, I'm going to say that the Redditors appear to be correct - that the additions needed for the colour also make FlashForge "Burnt Titanium" ASA also pretty hygroscopic.
My "dried" filament was in the Eibos Polyphemus for 12 hours on the ASA programme (70C no rotation) and I printed from the dryer. I'm currently doing a print of four of my test models (print time 17 hours+) with feed from the dryer, and it's set to 60C (because I've already dried this filament!). One point to watch though, the drying process also seems to make the filament a bit more brittle - I managed to snap the filament during loading when I tried this test print, so I was a lot more careful with the current print!
Hope this helps, let me know how you get on @fake_jello ...
PS I'm using a slightly tweaked version of the default Fibreology ASA profile.
RE: Flashforge ASA issues
Thanks for the testing and data, but based on the radius of the corners of that center test part being different than the left and right parts, I have to guess they were printed from different gcode files. That sort of invalidates the test results, doesn't it?
RE:
I noticed too the brittle effect on a spool of Fillamentum ASA after drying it for several hours at 65C on my PrinDry ProII, but only the external coils became brittle. I expect that the temperature was lower in the inner coils.
Strangely enough, the technical document released by Fillamentum on this matter, advises 2 hours at 80C for ASA, while Printdry recommends at least 4 hours at just 65C. Who is right ?. I guess it depends on the brand and color of the filament. Also the accuracy of the sensor and the capability of the machine to keep an even temperature in every part of the drier plays an important role.
RE: Flashforge ASA issues
Thanks for the testing and data, but based on the radius of the corners of that center test part being different than the left and right parts, I have to guess they were printed from different gcode files. That sort of invalidates the test results, doesn't it?
Not wishing to be rude, but no, you're guessing wrong, unless the slicer was doing something clever under the hood (actually I might have just hit reprint, but I can't swear to that). What I can be certain of is the the base geometry driving that was consistent. I will (sheepishly?) admit though that removing the modelled support from the rightmost one doesn't help any visual comparison.
RE:
Okay, I've completed testing on this and I'm standing by my findings* so - in case it helps any other poor soul - here's my recommendations:
- Nozzle temperature - this prints hot. For my last iteration (longer version of my model) I was using a DiamondBack nozzle running at 255/250C (1st/2+ layer). Cooling was set to flat 10% with 35% for bridges
- Bed. 110C seems to work, especially if you preheat the bed and allow it to stabilise/soak (15-20 minutes is ample). Also on the smooth PEI bed, wash clean and Magigoo. You can re'goo for 2-3x before the build up gives you print failures.
- Chamber. This confused me but I ended up having to override the 'default ASA' chamber temp to 50C on my Core One. Thermometer at the bottom of the enclosure said 32-34C, so I'm thinking that either the Prusa sensor is rubbish (unlikely) or else there's a heckuva gradient in the C1. A cooler enclosure seems to cause adhesion failure spots, which then act as crack starters for cooling issues.
- 1st layer prep. Treat it like TPU - so decent brim (my 'long' model had an 8mm modelled and a 10mm slicer-added one, the original 'short' model does fine with only the 8mm modelled brim) and run slow. I used 20mm/s for 1st layer print speed, 30 mm/s for external perimeters and 25 mm/s for top solid infill.
- Perimeters. This ASA (I haven't printed a lot of ASA, so if this is general thing then apologies) seems to suffer from cooling issue where more infill and less perimeters caused horrendous outer shell cracking. I've got a 3.6mm wall thickness and setting 8 perimeters made those come out quite well.
- Drying. 70C for 4 hours is fine - unless you've got a new spool, in which case just open it and print! Once dried it's okay, but if your print time is longer than 8 hours then it's probably safer to print from an (active!) dryer - 60C seems to work nicely.
Now, my esteemed Prusati - can someone explain why the Prusa material chart says to use the satin PEI sheet with ASA? Is it wrong, or am I either just 'doing it wrong' or very unlucky because the satin sheet didn't seem to work well with this at all!
I've also got a spool of "normal" black FlashForge ASA - I'm going to try a test or two with that, because I suspect that a lot of the issues with the FF Burnt Titanium ASA is down to the "Burnt Titanium" additives, given that Reddit etc shows a lot of complaints about the same colour in PLA and ABS.
(* I'm NOT a material scientist, so if there's barn door sized holes in my 'method' - or results - then polite corrections/suggestions are always welcome. I also claim no great expertise, but thanks to people on this forum I'm learning fast)