Filament is gathering on new mini2

Bought a new mini2 about 3 weeks ago. I am very new to this. The filament is gathering from the nozzle. I used the pad to clean the nozzle and the bed as the manual said to do but that did not help. Suggestions?

Thanks for any help.

Is it doing this during printing or prior to? I am by no means an expert. I purchased a used not working Mini ver 1. Once I had repaired the broken wire I discovere, I used Cura-Lulzbot to slice a model and print and found a similar thing to you. The first layer did not stick to the bed. Someone advised me to lightly sand the bed with 1500 grit wet or dry paper but I was still having the same problem. Eventually I discovered that the nozzle was not tight and was unscrewing, lowering itself and scraping of the first layer. Once I had tightened it, my problems went away and I have not needed to do anything else, it just works :slight_smile: Occasionally I do sand the bed surface if I notice that any portion of the first layer lifts at the beginning, but that’s it.

I will try that, I was also finding that it could be caused by the nozzle jamming. I saw a recommendation to do a cold pull, but you need nylon filament for that. So will get some of that filament as I will probably need it now or sometime in the future to clean out the nozzle.

Instead of nylon, get some of eSun’s cleaning filament. It works really well, has a very wide temperature range, and is easy to do cold pulls at around 90-110c.

Some basic debugging info is needed.

  • What filament are you trying to print? (PLA, PETG, etc. and which brand?)
  • What temperature are you using on the hot-end?
  • If you raise the Z-axis well above the bed and just ask it to extrude out several millimeters (e.g. 20mm) what happens?
  • What is your Z-offset set to?

When you first launched Cura LulzBot Edition (the first time ever) it would have loaded a part onto the bed and asked you to print it using the supplied sample length of PolyMaker PLA (in LulzBot Green color). How did that go?

You can cold pull PLA at 100°C. Push down on the tool head while pulling up on the filament. It will require a fair amount of force. If you can’t get it to pull out, increase the nozzle temperature in 5°C steps until it comes out.

Thanks for the help! Cold pulling helped, stuff did come out, but when I changed filaments I no longer had any problem at all. So maybe the PLA filament was not so good.

Possibly… PLA will vary from brand to brand, color to color, and even from spool to spool. Better brands tend to be more consistent. I’ve never really had issues with my PLA getting “wet” … but I have with other filaments (e.g. PETG).

If you raise up the Z-axis and just tell it to extrude maybe 20-30mm of filament, you want to see smooth extrusion … not bubbles and you don’t want to hear noises. Water in the filament will boil, turn to gas, and “pop” as it extrudes and you’ll both see and hear it. Don’t worry if the first few millimeters look like garbage (that’s normal for any filament that has been idle in the nozzle for a while and just after a retraction … over-retraction can allow the nozzle to pull in air, which will heat up, expand, and “pop” as it comes back out. So I don’t judge by the first few millimeters… but after it’s been extruding a bit (say 10mm) if it’s still coming out like garbage, you may have wet filament and it needs to be dried.

Also, as it extrudes, the filament should extrude straight down. If you notice the filament is trying to push to one side (a bit of bend in the filament just as it exits the nozzle) then you probably have a dirty nozzle and need to do a cold-pull.

Desiccant packs will keep the air dry in a storage bag … but they can’t pull any moisture out of the filament if it has already absorbed some. Only heat will get that out. I was using filament dryers (I tried eSun and PrintDry) but I find that they never really reach the temps they should reach to dry the filament (you can compensate by dying for an extra extra long amount of time). In the end, I bought a toaster over (after ruining a spool in my kitchen oven). Ovens are notoriously inaccurate and can have temp swings of 20°F … and over-heating the spool can ruin it (which is what happened to me). I found out that the Breville brand (and only the Breville brand) uses a technology that keeps the oven accurate to within 2° … so I bought one. That thing has been fantastic… I dry the spool in the toaster oven and the printing is greatly improved (assuming the problem with the filament really was moisture-related.)

what temp would you dry PLA at?

The PrintDry dryer recommends 45C (115F) for 4 hours.

This is an “it depends” answer. Here’s why.

The glass-transition temp for PLA is about 70°C … in other words at 70°C or above… you’ll spoil the filament (it will start to fuse together).

So under no circumstances should you dry at temps above 65°C.

But “it depends” because ovens can be wildly inaccurate (which is why I obsessed over finding an accurate oven). Ovens can (and often do… this is not rare) have a 20-25°F temperature swing while cooking. So you could imagine setting the oven to 65°C (149°F) … and having the filament spoiled anyway.

So to be “safe” … if you don’t have an oven known to be highly accurate… set it below 65°C… 50°C is often the recommended temp… but you could dry filament at 35°C if you just let it run for many more hours.

E.g. at 50°C it will probably be dry in about 3 hours… but at 35°C … may you let it go overnight (8 hours).

Also… keep filaments in sealed bags and toss in a desiccant pack. You can buy re-dry-able desiccant packs (you toss them in a convention oven or even a microwave … heat them up, and it forces any moisture that they absorbed out of the desiccant and they’re ready to absorb more moisture out of the air.)

I have been using a food dehydrator but the lowest temperature setting is 35C, 95F. If I use the stuff right away after about 4 to 6 hrs of drying it works better than before drying. I store it in ziplock bags along with the silica gel packages that I dried with the filament and I suck the air out with a vacuum cleaner which seems to keep the same until I open it next but usually in a day or too the filament prints ‘blobby’ and eventually restricts/plugs the nozzle. It seems to happen worse with white filament including some quite expensive Lulzbot PLA that I have.