PA - Nylon Printing  

A picture of a failed print would help us diagnose issues.

I haven't used that particular filament but non-CF nylon in general behaves very like PETG when printing, they are both polyamide, but Nylon is the most hygroscopic of all the usual filaments so drying is particularly important.

Cheerio,

RE: PA - Nylon Printing

Posted by: @diem

non-CF nylon in general behaves very like PETG when printing, they are both polyamide

I don't think PET (and hence PETG) is a polyamide; it's a polyester. Nevertheless, both materials are known to be pretty hygroscopic.

Overture states the following on their website. It seems to mainly say that supports must be removed soon after printing -- but maybe it also implies that printing with Nylon that is already damp may cause stronger bonding to the supports? 

If this nylon material is used as the support material for itself, please remove the support structure before excessive moisture absorption. Otherwise the support structure can be permanently bonded to the model.

RE: PA - Nylon Printing

it's a polyester

Oops, yes, you're right.  For some reason I keep repeating that one 'though I do know better.

- but I do stand with the printing characteristics.

Cheerio,

RE:

I've had reasonable luck with Sunlu Easy PA, using the settings for Tectonic-3D KRATIR PA6.66 CF but unchecking Abrasive material in the Filaments | Advanced tab. They are both a mix of Nylon 6 and 66 and the temperature ranges are similar. Printing turned out well, with minimal stringing and good features, with only fair bridging. I had to clean off a few loos threads. The layers stick together well. The winding on their spools is very loose. It hung up once and wrecked a print. The PTFE tube is a little bent but it seems no issue in the extruder. It worked properly the next time. I dried it at 70 C for a day and returned it to the drier overnight when not printing with it.

Regards,

Mark

RE: PA - Nylon Printing

I recently bought some Sunlu Easy PA too.  For my first print I just used the first PA preset I found (Filatech), but it didn't come out very well.  The material was noticeably scorched and the geometry was a bit distorted over the first mm or two.  So then I checked the recommended print settings and was surprised to see that it needs quite a cool build plate - they suggest 30-50 degrees, and 250-270 degrees for the nozzle.  I went for the middle of that range (40/260) and result was vastly improved.  As a test I went to the bottom of their range (30/250) and got an even better result.

I'm still struggling a bit because the printer's default behaviour with a material defined as 'PA' isn't quite right for this filament - it oozes a bit at the idle temperature, it gets stuck in the extruder when it unloads the filament (wonky filament tip), and the printer wastes a lot of time heating the print bed to a much higher value before then taking another age to drop back to 30 degrees.  So I'm still working on dialling it in properly.  The idle temperature should be easy to fix, the tip forming is a matter of trial and error with the ramming settings I think, but the default bed temperature is eluding me at the moment.  Just a matter of digging around in Prusaslicer though I hope, but I'd welcome any advice.

The result will be worth it though - it seems to produce nice prints that feel strong and slick, like Nylon should.  For a gear part that I'm working on it should be ideal.

RE: PA - Nylon Printing

I went through all the PA presets and chose one with the closest temperature setting to those recommend by Sunlu and the most similar material, Nylon 6/66. 

I don't have any issues getting stuck in the extruder. I do get some oozing. I do have to cut the filament end at a diagonal to push it through the filament sensor.

All the temps are found in the filament tab. The chamber preheat does take time, but I haven't had any warping, so it's a tradeoff.

Regards,

Mark

RE:

Posted by: @mark

All the temps are found in the filament tab. The chamber preheat does take time, but I haven't had any warping, so it's a tradeoff.

I have no objection to the chamber pre-heat and the heat soak, and there's always the option to skip them if I judge that the printer is still hot enough from a previous print, or the part is small enough that it doesn't matter.  But I don't think what I'm seeing is related to those.  I guess it could be - maybe it judges that the best way to pre-heat the chamber is by having a hot build plate.  I'll try setting a lower minimal chamber temperature.

But Sunlu recommend a 30 degree bed temperature, so I guess that chamber temperature isn't critical, and despite me having no such high temperatures set anywhere in the filament tab the printer still wants to take the bed to a high temperature (I don't recall exactly, but I think it was over 100 degrees), before dropping back to the 30 degrees that I set.  It's that needless heating and cooling cycle that I'd like to eliminate (for which there's no 'skip' option), especially the cooling since that takes a very long time.  I think it may be related to some conditional commands in the gcode based on the filament type being defined as 'PA'.

RE: PA - Nylon Printing

Posted by: @mark

I don't have any issues getting stuck in the extruder. I do get some oozing. I do have to cut the filament end at a diagonal to push it through the filament sensor.

Ah, I think I see a difference - I'm using an MMU, but if you're feeding filament through the filament sensor I guess you're not.  I believe that a non-MMU printer has some default ramming configuration, that I don't think we can modify in the slicer.  This seems to produce filament tips that unload and load cleanly.  I'm only guessing, but I think that the ramming parameters in the 'Toolchange parameters with single extruder MM printers' aren't used unless you define multiple extruders, e.g. with an MMU.  And I think the default ramming configuration in that case is different from the non-MMU ramming configuration - that's what I found with ABS anyway.

So in my case I need to work on the ramming configuration for this filament so that the tips formed by the MMU configuration are the same as those formed by the non-MMU configuration.

RE: PA - Nylon Printing

Posted by: @chris-hill

Ah, I think I see a difference - I'm using an MMU, but if you're feeding filament through the filament sensor I guess you're not.  I believe that a non-MMU printer has some default ramming configuration, that I don't think we can modify in the slicer.  This seems to produce filament tips that unload and load cleanly.  I'm only guessing, but I think that the ramming parameters in the 'Toolchange parameters with single extruder MM printers' aren't used unless you define multiple extruders, e.g. with an MMU.  And I think the default ramming configuration in that case is different from the non-MMU ramming configuration - that's what I found with ABS anyway.

So in my case I need to work on the ramming configuration for this filament so that the tips formed by the MMU configuration are the same as those formed by the non-MMU configuration.

You are correct. I don't have an MMU. The vast majority of what I print are functional parts, so I don't use more than one color or material. For the Nylon, I am more interested in layer adhesion and strength, so I tend toward the high end of the temperature range and accept a few visual anomalies. I do wish the bridging was better as takes time to clean up the few strings hanging down. Overall though, the parts are pretty good.

Regards,

Mark

RE: PA - Nylon Printing

My experience with Fishy Filaments and other nylons is that they need at least 24 hours of drying before even attempting to print and you really need to keep them in a dry box as they will almost immediately start absorbing moisture.

The way I test it is to print a very small quick test print, and if the surface isn't "buttery" smooth its not yet dry.

RE: PA - Nylon Printing

Posted by: @laura-f-farrell

My experience with Fishy Filaments and other nylons is that they need at least 24 hours of drying before even attempting to print and you really need to keep them in a dry box as they will almost immediately start absorbing moisture.

The way I test it is to print a very small quick test print, and if the surface isn't "buttery" smooth its not yet dry.

I have a dryer and dry all filaments, sometimes for days before using. It always makes things better.

I ordered a hardened nozzle and will try some CF filled filament, either PA or PC, haven't decided which yet. I've had good luck with both in their non filled versions.

Regards,

Mark

RE: PA - Nylon Printing

I trying to get up to guts to print Nylon with Kevlar....

RE:

I've had really great success with Polymaker Fiberon PA6-CF on a PA sheet. Doesn't warp and the layer adhesion is excellent. However I run it through the drier overnight, transfer it to the dry box and print directly from the dry box (perhaps I'm over doing it). I also anneal the printed parts at 100C for 10 hours. After doing this I get (nearly) indestructible prints. I haven't had the need to print anything with supports yet. Waiting for the BondTech tool changer so I can print with PVA (for example) as the support material. 

RE: PA - Nylon Printing

Cool, I have a few rolls of that laying around.  Different note: I've been picking up 3kg rolls of Fiberon PETG RCF08, and the stuff prints wonderfully. I also just picked up a 3kg roll of their ASA-RCF08... so I'm looking forward to playing with those.  Obviously, they don't need to dry anything like the various Nylons, but I am liking the Polymaker Fiberon. Also, if you purchase from their website, you can use the code polymakerfirsttry on your first purchase and get 15% off of any of that purchase, which is how I get a good deal on the nylon products.

RE: PA - Nylon Printing

I haven't pulled it out yet, but Colorfabb PA-CF low warp printed nice on the P1S so would expect it to be even better on the Core One. I struggled with it until other brands CF infused nylon profiles appeared in Prusa Slicer. On the Bambu Lab it was very nice on the generic pa-cf profile.

RE: PA - Nylon Printing

First layer adhesion, warping and release after printing of many of these "specialty" filaments is often an issue. I use my "magic sauce" mixture of glue stick and Windex on the stock PEI sheet, and sometimes skirt / brim / draft shield and have had good luck with ASA, printed lots of it, PC, PA, TPU and will try others. You just have to learn each filaments characteristics. It's not PLA or PETG.

Regards,

Mark

RE: PA - Nylon Printing

Posted by: @mark

First layer adhesion, warping and release after printing of many of these "specialty" filaments is often an issue. I use my "magic sauce" mixture of glue stick and Windex on the stock PEI sheet, and sometimes skirt / brim / draft shield and have had good luck with ASA, printed lots of it, PC, PA, TPU and will try others. You just have to learn each filaments characteristics. It's not PLA or PETG.

Regards,

Mark

And, drying in a heated dryer for hours to days always, Always, ALWAYS makes things better. I don't print anything now without drying first.

Regards,

Mark

RE: PA - Nylon Printing

Slightly off topic but you can over-dry PLA and PETG. I've had to chuck out spools for becoming brittle after spending too much time in and out of driers. Back on topic, I love nylon. The biggest downside is it only seems to be limited color choice. CF comes in black (which makes sense). There are the glass fiber versions that come in a variety of colors, however they are very expensive (from what I've found so far). 

RE:

Posted by: @hyiger

There are the glass fiber versions that come in a variety of colors, however they are very expensive (from what I've found so far). 

Of course with white nylon you can actually boil the parts in dye to color them but not sure I want to go down that road.