Nylon Prints start going bad suddenly

[morenoa0922 0]

I've  been trying to print a prototype piece using Nylon (needs to be strong at compression). 

 

I've tried the following things:

 

1.- I leave the filament on a filament dryer all night 

2.- Print standing up

3.- Print sideways

5.- Replaced extruder head with a new one

6.- Used an Ultimaker 2+

7.- Used an Ultimaker 2+ Extended

 

And every time, after some hours of print, when the piece reaches 10-13 mm the print starts going bad... like the material flow is reduced, to a point where it stops printing...

 

I use Simplify3d with Ultimaker Nylon settings. I've been more than a week on this and keep getting the same result... Any ideas will be appreciated.

 

[geert_2 557]

I have no experience with nylon, but from the recommendations I read here before: did you keep the spool in a dry-box with lots of desiccant during printing? And with a teflon tube from that box to the printer? So that no normal moist air comes in contact with it? It is known that especially in a moist environment, in a few hours nylon can absorb so much water that is can not be injection moulded anymore. I guess the same would apply to 3D-printing?

 

Of course, theoretically there could be other causes too, such as dust accumulated on the filament and pulled into the nozzle, or the spool tangling up after some time of printing, or filament burning in the nozzle and gradually clogging it, etc..., but I guess you checked for these.

 

[CapableQuad 10]

I agree with geert_2, I print with nylon a lot, store the nylon in a dryer and feed the printer directly from there. From my experience nylon can absorb enough moisture  from a humid atmosphere to affect the printing quality in just a few hours. Listen for faint popping or cracking sounds, this may be an indication that moisture in the filament is an issue. Of course it could be some other problem (or combination of issues) involving the printhead or temperature settings.

[Brulti 177]

As the replies above said, Nylon needs to be kept in a drybox even when printing, else it will absorb humidity and go bad. You can buy dryboxes in specialized shops or find plans to make your own on this forum or websites like thingiverse or youmagine. It's actually quite easy to do.

[morenoa0922 0]

Thanks for your replies... 

 

As I mentioned on my initial post, I dried the filament on the dryer shown in the picture, for more than 12 hours every time I attempted a print. Finally I replaced the roll with another one, and the print came out. 

 

I'll leave the misbehaving filament for a couple of days in the drier, maybe that will do it.

[CapableQuad 10]

|Hi, I have the Printdry system too, and it works very well for me. My nylon filaments are normally stored in a drybox and then I move the spool to the Printdry from where I feed directly to the UM3.

I normally set the Printdry at about 55⁰C. If I have ever left a spool of nylon exposed, then I dry it for a couple of days before I use it. This system seems to work quite well with no problems. I used to significant issues before I started using this process.