UM Nylon warping

[ynagersheth 0]

Hi!

I have been printing with UM nylon since a while. I used to have pretty successful prints (unwarped). My last few prints have started warping and cant find out the reason why as all the settings in Cura are the same for most of the prints.

I currently use glue stick and 85-87 degree bed temp as I have 8 to 14 hour long prints.

Can anyone please suggest any other stronger bed adhesion methods for long prints?

Thanks!

I am going to try masking tape and liquid glue instead of the glue stick

Also my brim lines have not been coming great lately they lift of near the print area ( I use 15 brim lines and lines 11-14 lift for some reason after a couple of hours) and sometimes they curl and dont stick to the bed perfectly resulting in small air gaps that I try to cover with glue but eventually warps the print.

I use a 0.8 mm nozzle, 252 as the nozzle temp, 0.26 as initial layer height and 0.8 as brim line width. I keep the nozzle close to the bed to get good squish about 0.1 to 0.12mm close to the bed.

These settings have worked fine till now.

Do you think I should change them?

Thanks!

[gr5 2,271]

I'd like to see a photo because about 60% of the time I give advice and then I see the photo and I have to retract everything. However from your description you need the glass and the nozzle closer together. Too big a gap explains both parts coming loose (aka warping) and also the brim not sticking at all. You need that first layer to squish more. Don't re-run the bed leveling procedure. Instead just turn the 3 bed screws a half turn CCW to move the glass up.

More details in this video:

[amedee 349]

For nylon you need PVA glue...

[kmanstudios 1,120]

If nothing has changed, assuming all other factors are the same (adhesion, temps, etc.) and the Nylon is the same, I would think that maybe an environmental factor may be involved as well. Or, is it a new batch of Nylon?

We had a humid weekend here last week and it made my PVA not want to stick to plastics. Did ok on the glass bed, but a trial run just got worse and worse as the humidity got to it. I could hear the cracking of the filament grow as the night progressed.

Nylon absorbs moisture a lot too. Sometimes I hear it crackle :(

[geert_2 558]

Cleaning the glass plate with soap-water or some window cleaners might also destroy bonding. Soap does remove oils, but it itself is anti-stick: you can not glue anything to soap. Could this be a cause?

So, after cleaning the glass plate with any method, I always clean it again two times with warm tap water only (pure, untreated, not softened, no additives).

As kmanstudios says, the weather can have an influence too. Before discovering the "salt method" (=gently wipe the glass plate with a tissue moistened with salt water) to get my PLA to firmly stick to the build plate, on humid days it would often come loose. While on freezing cold and dry days it would stick well. This without any other differences in models and circumstances.

I guess the steam caused by water evaporation in wet nylon might also reduce bonding? You can not glue to steam. So, drying the nylon prior to printing, and then keeping it in a box with disseccant while printing, might also help?

[kmanstudios 1,120]

I have not tried geert_2's method of salt yet, so I cannot comment.

But I will strongly echo the clean glass statement. I go the extra step (because I am not using salt or tested the method yet) of cleaning with alcohol. Then I put on my special Papa K's Slurry slush.

And when a print comes off that does not pull up the slurry, I will still wipe the surface gently with alcohol (right over the PVA slurry). Basic over the counter, 79 - 99 % pure. I always use the highest grade I can get locally just to cut down on contaminants.

[geert_2 558]

Just to be clear: my salt method works very well for *PLA* only as far as I know. So for PLA it can replace all other bonding methods for me. But it does not work for ABS. For NGEN it works a little bit. I have no idea what it does for nylon or other materials (let us know if you would ever try it), but I guess you have better chances with dilluted wood glue, glue stick, hair spray, 3D LAC or so.

As kmanstudios says, I have also noticed that cheap alcohols and other cleaning aids do leave traces of oils or soaps on the glass, sometimes making things worse. Isopropyl alcohol (as also used in desinfectants) seems to work better to dissolve oils.

[kmanstudios 1,120]

Just to be clear: my salt method works very well for *PLA* only as far as I know. So for PLA it can replace all other bonding methods for me. But it does not work for ABS. For NGEN it works a little bit. I have no idea what it does for nylon or other materials (let us know if you would ever try it), but I guess you have better chances with dilluted wood glue, glue stick, hair spray, 3D LAC or so.

As kmanstudios says, I have also noticed that cheap alcohols and other cleaning aids do leave traces of oils or soaps on the glass, sometimes making things worse. Isopropyl alcohol (as also used in desinfectants) seems to work better to dissolve oils.

 

My bad...I did mean the Isopropyl. DurrrhhhhhhLOL

My favorite method of adhesion is recycled PVA. So far, it has worked well, even up to 100° C.

[MechDesigner 3]

I know you are using nylon. I have not tried it yet.

I have pretty good luck with ABS on painters tape as long as I wipe the top of

the tape with isaphrol alcohol, but with CPE it will not stick to the tape

I had to add glue stick to the tape, kind of thick and lightly

spread with a paper towel. I start the speed at about 80% and after the second layer

starts I go back to 100%. Also after the brim is done I tape the edges of the brim

down. for larger parts, good luck, the larger the prints easier they warp.

[yellowshark 153]

In my experience (with Taulmann nylons) you must make sure the nylon is dry. Any hissing or visible vapour as it leaves the extruder will indicate it is not. If there was any time gap in using the filament I would always pre-warm in the oven - be careful you get the temp right; once I warmed two different nylons at the same time, overlooking the fact that one had a lower melting point and got, well, melted!

[gr5 2,271]

I've been preheating my nylon on the heated bed with a towel over it and getting really great results. Basically if I see *any* bubbling (it should come out clear - not like snow) then I know I didn't heat it long enough. For taulman bridge nylon, 3 hours at 95C worked for the nylon I had unspooled and placed directly on the glass. 105C worked for me also.

Just unspool the qty of meters you need for your print, put those flat on the glass, put the spool on top, and a towel on top of that. Make sure your nylon doesn't melt at the temp you are heating to. (pre test a little bit of nylon at a higher temp). 80C should be a safe temp for all nylons but that might take more than 3 hours - I don't know.

[yellowshark 153]

Nice 8) Are your temps with a fully enclosed (including top) or an open printer?

[gr5 2,271]

For me, I have a box on top of the printer. Unmodified. Just taped on top. when I do high temp materials like abs, nylon.