XL multi tool blob or blobs on purge tower
Hi, my Xl Multi tool is creating blobs of filament on the purge tower, that lead to....
1/ Me trying to snip them off while the print is in progress, and sometimes causing a crash, because my hand gets in the way of the tool, or....
2/ The blob happening overnight and eventually causing an unaided crash.
After recovering from a tool crash (whatever the cause) there is always a bit of layer shifting, which detracts from the finished model.
I have searched the web for solutions to this, and see things like, leaky nozzles etc causing this, but I don't think this is happening here. It seems to be more common after about 16 hours of printing with long print jobs. This is V frustrating, since it requires a restart of the job, and the printer is tied up for another day or two.
RE: XL multi tool blob or blobs on purge tower
I meant to add, that it does seem to be associated with particular tool, in my case the black tool, and the white tool. I am using Sunlu PETG atm.
RE: XL multi tool blob or blobs on purge tower
Did you set the nozzle seal at the correct height?
https://help.prusa3d.com/guide/4-first-run_482742#663410
I would double check that, then it could be a difference in temperature settings. or possibly "wet" petg that would need to be dried.
Shane (AKA FromPrusa)
RE: XL multi tool blob or blobs on purge tower
Thanks for the reply Shane. Here is a print that is currently in progress. The layer shift about 1/2 way up is due to a rehome after a crashed tool, caused by a blob. I set the nozzle seals as per the build instructions.
I suspect we will see a lot more of this when people start using huge INDX arrays. Typically it occurs about a day into a longer print with PETG or TPU.
For me that's how long it takes exposed filament to absorb enough moisture to start oozing and with 5 heads the filament is not being used up as fast as the outer layers on the spools deteriorate - the answer of course is to pre-dry the filament and print it from a drybox.
Cheerio,
RE: XL multi tool blob or blobs on purge tower
Thanks for the reply Shane. Here is a print that is currently in progress. The layer shift about 1/2 way up is due to a rehome after a crashed tool, caused by a blob. I set the nozzle seals as per the build instructions.
I would look at a few things.
When its printing if you hear some pops, crackles or snaps, the filament is "wet" and it would need to be dried.
Also seeing a lot of stringing on it, I would laso look at the temp settings and see if htey need to be adjusted / tuned in
Shane (AKA FromPrusa)
RE: XL multi tool blob or blobs on purge tower
It looks like you are using multiple mods on your printer. Especially nozzle wipers, shouldn't they prevent this kind of issue?
It reminds me my very first print with the XL: the default filament profile was too hot, and the filament hadn't been dried. Since then, I never start a multi-tool print without drying the filament first, and depending on the print geometry and the filament, I adjust the temperature if needed.
I also noticed that the thermistor is positioned differently relative the fan. I guess the actual temperature inside the hotend is higher than on other printers.
The rare times I've had a "blob" were when a filament stayed too long at the parking position. When it comes back to the tower, it spits out liquid filament. Once, during the initial purge, a drop fell onto my hand and burned me. So now I never keep my hands underneath. 😄
RE: XL multi tool blob or blobs on purge tower
Cheers Shane, you said "When its printing if you hear some pops, crackles or snaps, the filament is "wet" and it would need to be dried. Also seeing a lot of stringing on it, I would laso look at the temp settings and see if htey need to be adjusted / tuned in" The filament is fairly dry, it's autumn here now, with daytime averages around 30C. I do have a heated drybox, but that only holds 4 spools of filament, so if it does help, Murphy's law might come into play :). When you talk about temp settings, I have always used the defaults for whatever filament type I am using (PETG atm), is this likely to be different to the manufacturer's temp recommendations? Whilst there are no noises associated with damp filament, it does ooze a bit as temp increases from cold, I put this down to thermal expansion, but it could be excess moisture in the filament as well.
Thanks for the reply Kachidoki, the various nozzle wiper mods are intended to mitigate oozing, and particularly the brush on the first toolhead does seem to collect some filament. Also, I've learned to press "pause" now, rather than trying to snip off blobs while the printer is printing :).
RE: XL multi tool blob or blobs on purge tower
Cheers Shane, you said "When its printing if you hear some pops, crackles or snaps, the filament is "wet" and it would need to be dried. Also seeing a lot of stringing on it, I would laso look at the temp settings and see if htey need to be adjusted / tuned in" The filament is fairly dry, it's autumn here now, with daytime averages around 30C. I do have a heated drybox, but that only holds 4 spools of filament, so if it does help, Murphy's law might come into play :). When you talk about temp settings, I have always used the defaults for whatever filament type I am using (PETG atm), is this likely to be different to the manufacturer's temp recommendations? Whilst there are no noises associated with damp filament, it does ooze a bit as temp increases from cold, I put this down to thermal expansion, but it could be excess moisture in the filament as well.
Thanks for the reply Kachidoki, the various nozzle wiper mods are intended to mitigate oozing, and particularly the brush on the first toolhead does seem to collect some filament. Also, I've learned to press "pause" now, rather than trying to snip off blobs while the printer is printing :).