Junk Filaments and Moisture

[Capt. John]

Been printing now for 6 months. Major part of my learning curve has been spent
fixing self inflicted problems that raise hell with the V3B hot end from junk filament
purchased for Amazon and Makergeek. Amazon? ...never buy a unrated filament, then
do so at your own risk. Makergeek's extra glow ABS caused me 2-3 days of grief,
that had to be mis-labled PLA.

Next issue and it's a big one is keeping the filament dry. Moisture content and how to remove
it and keep my used filament dry is the next thing on my list. Figured out excessive droll was
from moisture expanding inside the hot end.

I use a lot of PET+ because it's stronger than ABS. Recently, purchased a spool of clear from Amazon.
Thought no biggie, when the spool arrived with torn, broken vacuum seal and missing the dry stuff packet.
OK, more problems, this PET+ was more grief with droll that seemed to go on forever, leaving zits
on my models every retraction cycle. Good thing about Amazon is their return policy and getting
your money back asap.

Another bad idea that I had was purchasing the tiny clog clearing drill off Makergeek.
This crap tool broke off inside one of my hot ends, after it made the opening in another
way too large.

I'm done trying to clean hot ends, for 10 bucks new from Makergear will save me one helluva of time.
Sure it's 10 bucks out the window, but what's your time worth? ...not to mention the frustration meter?

Something worth sharing is keep hot ends and drives dedicated to either PLA, ABS, or PET+.
Changing different kinds of filament back and forth in the same hot end is where I've had too many issues
to continue this practice.

If you have a good way to store filaments, or a small affordable dehumidifier system
please share it.

[Tim]

There have been a number of posts about setting up good dry boxes. It appears that you can get by keeping it really low-tech: A decently sealed container of the sort you can get from Costco, the Container Store, etc., and lots of dessicant packs that you can buy in bulk from Amazon. Before storage, bake the moisture out of your spools by putting them in the oven. There are probably tables somewhere of time vs. temperature. If you look at various blogs and forums, you'll get wildly varying answers, so I won't try to add more random values to that here. Just keep the temperature below the point where it will warp your spool, and let it dry out for a couple of hours, then put it in the box with a lot of dessicant.

I've also seen some posts where people put a hole in the top of the dry box and fed the filament directly from the box to the printer, so that the filament never touches the ambient air. This is probably overkill; your filament won't pick up much moisture from being in the air for a day or two, and it's probably good practice to remove the filament if the printer is going to be idle for longer than that. Of course, sometimes the problem is that you intend to get back to working on that print, but various other things take priority, and before you know it, two weeks have passed with the spool sitting there in the air. So maybe it's not a bad idea to feed directly from the dry box into the printer.

Keep in mind that all this really depends on the type of plastic. PET+ is supposedly hydrophobic. So if it's dripping, it's almost certainly not due to absorbing moisture, but more likely and indication that you should turn down the extruder temperature a few notches, and maybe increase the retraction amount. PVA, on the other hand, absorbs moisture like crazy (it's water soluble, after all), and flexible filaments are pretty bad about absorbing moisture as well.

Also, note that being hydrophobic, most PET+ is shipped without dessicant on purpose, because it doesn't need it.

From reading the forum for a long time, I've come to the conclusion that the best way to clean a hot end is with a propylene torch. The V4 is the best for this, because it's the easiest nozzle to get on and off, as long as you're careful not to put so much torque on the nozzle that you snap the hot end at the heat break. So maintenance will get a lot easier when MakerGear starts shipping V4s.

[Capt. John]

Thanks Tim, very informative.

V4? now that I have ordered parts to rebuild 3 V3bs, kinda seems like I should have waited.

Does the V4 used the same printed extruder piece, or part like the v3b?

[insta]

Shoulda told me you wanted V3Bs, I have 3 I'm not going to be using

For what its worth, Taulman 618 does an amazing job of cleaning nozzles, if you use it in a cold pull. It's honestly worth buying a roll just for this. I was astonished the colors it was coming out with for several iterations. It generally takes about 6-7 iterations to completely flush a nozzle for me (on another machine with a Hexagon hotend). Haven't had a chance to try the M2 yet with the new hotends. I usually poke a ball-end allen key down into the hotend to get the barrel mostly empty, then start chasing with Taulman until it just starts to peek out the nozzle tip. At that point, cool to room temp, reheat to 160, and provide very firm upwards pressure as soon as it crosses 140C. Cut the last inch off the Nylon and repeat. It generally takes me about half an hour to clean a nozzle, and 95% of that is waiting for temp up / temp down, so I just have the TV on in the room.

[Tim]

I'm not aware that MakerGear has a single V4 extruder setup, although I expect that they have one under development in-house somewhere. The dual extruder setup has a similar but slightly smaller printed extruder mount, and the part of the extruder mount that links the two extruders in the dual setup is machined. The main difference is that there is a gap, a complete physical separation, between the top of the hot end and the rest of the extruder mount. The nozzle, heat break, and heater assembly comes away with the turn of a machine screw. But MakerGear hasn't made any promises for when they will start selling the V4. Makes me feel lucky to have signed up early as a beta tester!

[jimc]

back when i was using the v3b i agree with john. switching plastic types causes a bunch of issues over time. having one dedicated to each plastic is the way to go. the v3b is a really nice printing hot end but it does have a somewhat long hot zone due to it having no real heat break in the brass tube. this leaves a long section of melted plastic that builds up over time tightening things up. my e3d i have been using quite awhile now has a very short hot zone and i have yet to have an issue with that getting tight. i originally was going to get one for each plastic type like i had planned with the v3b but it seems i dont need to with this. not sure of the v4 but i do remember someone saying that has a nice short hot zone as well. a short hot zone allows for better extrusion control and seems to be the new development with hot ends so im sure rick set the v4 up and its done right!

[Capt. John]

Pieced together an old hot end. New barrel and tip, and now it prints amazing well.
As good as new. ABS now prints like velvet, 2 tone when the light bounces off it
with no annoying droplets. For the $20 bucks, this is a bargain compared to cleaning
out old tips and barrels.

Ordered parts on Monday, came out of Ohio to Michigan arrived on Wednesday.
Karen is an asset to those of us who need parts, because they do not sit on orders.