Printing large parts with Nylon and PVA

[jav 0]

Hi,

first i would like to say hello to the community as it is my first post.

I was trying to print some large parts using UM Nylon filament black and I wasnt able to get the perfect combination of parameters and also all my tries was wrong.

My first tries was using the cura profile and with small parts I obrtained good results but when the height of the part exceed about 15 mm I started to get underextrusion and finally total oclusion of the extruder.

Then I made some test changing these parameters:

bed temperature 70 º (from 60 º that cura profile indicate)

extrusion temperature 250 (from 245)

with these parameters I had serious troubles with bed adhesion and i watsed a lot of material. Also with these parameters i also had underextrusion and total oclusion in the end.

Then i tried to add some dimafix spray and the adhesion get worse, maybe the glue works better with nylon? but I run out of it.

Then I changed the settings again:

bed temperature 70

extrusion temperature 260

cooling fan speed 0 )from 40%)

with these parameters i have a good extrusion even in large parts but also troubles with bed adhesion.

To solve the bed adhesion I try to use PVA as raft and it works well.

now i have other problem, i need to build a large part with support structures and I need to use PVA in the interfaces between support and part because of the complex geometry but i cant get a good adhesion between Nylon and PVA and i end up having awful results (between PVA and Nylñon it works well).

Does anyone try to use nylon in combination with PVA?

does anyone have accurate values to print with nylon UM?

Thanks!

[gr5 2,172]

Do you have the UM3? Or are you doing this with an UM2?

The PVA and Nylon that UM sells are different from other brands as far as I can tell and they work very well together. Even better than PVA and PLA. I strongly recommend you start with UM brand and use the defaults in Cura. Default temperatures. Default horizontal expansion. But it's okay to print slower than the defaults. I found they worked very well together.

If you are having trouble with something sticking to the bed it's usually because the nozzle is too high above the glass. You can experiment while it's printing the bottom layer by simply pushing up on the glass and if it starts sticking better then just turn the 3 screws an equal amount to move the glass closer to the nozzle.

[Labern 774]

Also, make sure you keep firmware and cura up to date as possible as UM is constantly making improvements to the default profiles.

If you hear lots of little pops and crackles when Nylon is printing then it may have soaked up too much moisture and may need drying out. This can cause all sorts of issues when printing.

[jav 0]

Im using nylon and PVA materials from UM. My machine is a UM·. Im experiencing under extrusion in nylon parts higher than 15mm and in PLA parts higher than 140mm.

[gr5 2,172]

You didn't say if this is um3.

Well there are many things that can cause underextrusion. For example if you print CF filament (carbon fill) it can wear down the bumps in the feeder until they are smooth. Printing too fast or too cold (240C is plenty hot!). 15 other causes. What printer is this? What are all the print speeds (cura has maybe 10 different speeds in a given profile).

[Gigi 43]

Ultimaker Transparent Nylon.

Cura 2.5   draft 0.2 profile recommended .

First attempt was with hairspray but after few layers the print was raising off the build plate on the extremity.

Then i used the glue stick from my UM3 and everything is ok.

Printing a box cover 11 x 6 x 5 cm.(wall 1.5mm)

Bottom already printed.

Edited April 9, 2017 by Guest

[Gigi 43]

Not bad for draft print with nylon.

[BWilt 0]

Do you have the UM3?  Or are you doing this with an UM2?

The PVA and Nylon that UM sells are different from other brands as far as I can tell and they work very well together.  Even better than PVA and PLA.  I strongly recommend you start with UM brand and use the defaults in Cura.  Default temperatures.  Default horizontal expansion.  But it's okay to print slower than the defaults.  I found they worked very well together.

If you are having trouble with something sticking to the bed it's usually because the nozzle is too high above the glass.  You can experiment while it's printing the bottom layer by simply pushing up on the glass and if it starts sticking better then just turn the 3 screws an equal amount to move the glass closer to the nozzle.

I have a UM3 extended. I have been trying to print with UM Nylon and UM PVA and i have had issues of the nylon warping and not adhering to the print bed. I have also had multiple print stop or not print at all. I have had lots of success with PLA and PVA but no success with Nylon. Is it possible to print nylon with the .06mm profile? If so are there any setting that I need to change to have a better success?

[Gigi 43]

https://ultimaker.com/en/community/prints/31844-baby-groot

[gr5 2,172]

Yes you should be able to print nylon. It's important to squish it very well into the glass so maybe turn your 3 leveling screws CCW a half turn (and with autoleveling off!) to get it to stick extra well. Also use some pva glue (glue stick, hairspray or wood glue mixed with 90% water) and make sure it's very thin so if you use glue stick then take a wet tissue and spread it around well until it's all wet and very thin and let dry.

Nylon shrinks quite a bit but because it's more flexible than PLA it doesn't need to stick quite as well to avoid warping. That flexibility helps it stretch a bit to spread out the forces. But also use brim. That helps it stick well also. It helps keep the air from slipping under the corners.

[BWilt 0]

Yes you should be able to print nylon.  It's important to squish it very well into the glass so maybe turn your 3 leveling screws CCW a half turn (and with autoleveling off!) to get it to stick extra well.  Also use some pva glue (glue stick, hairspray or wood glue mixed with 90% water) and make sure it's very thin so if you use glue stick then take a wet tissue and spread it around well until it's all wet and very thin and let dry.

Nylon shrinks quite a bit but because it's more flexible than PLA it doesn't need to stick quite as well to avoid warping.  That flexibility helps it stretch a bit to spread out the forces.  But also use brim.  That helps it stick well also.  It helps keep the air from slipping under the corners.

Thanks! Ill try this out!