PCL printing of self-made filament

[Till187 0]

Hello everybody!

I'm trying to print something (a simple cube) out of PCL (Polycaprolactone, Mw=80k) and I'm using an Ultimaker S5 to do so. 

Unfortunately, the print will not stick to the Glass bed but instead accumulates around the nozzle. Do you have any tips for me on how to print PCL?

Some specs:

Nozzle: AA0.4 130°C printing temperature

Bed: Glass, 40°C with glue at the spot where the print should be

Speed: 20 mm/s

Fan Speed: 100%

 

One further problem might be that I have to make the PCL filament myself, so the thickness of the filament is only approximately 2.85 and maybe not exactly 2.85mm. 

What I've already tried was to do manual leveling of the bed, because I thought that maybe there was a problem with the nozzle being too far away from the bed. Still no better result.

Any help is greatly appreciated!

 

[MariMakes 178]

Hey @Till187,

 

Welcome to the Ultimaker Community 🎉

 

I don't have a lot of experience with PCL, so I had to ask our Material Experts.

They mentioned to watch the following
- The buildplate temperature can be 0
- In doubt you can probably print even colder.
- Make sure to clean your buildplate before applying the glue
- Consider chanign your glue.

They also mentioned that it's a pretty tricky material to print with. 

You can also consider using the following plug-in to print a temperature tower to find the correc temperature you need. 
https://marketplace.ultimaker.com/app/cura/plugins/Kartchnb/AutoTowersGenerator

[Till187 0]

Hey @MariMakes,

thanks for your tips, I tried them but could not yield better results unfortunately. 

 

Something else I now noticed, which might be a source of error, is that the extruder is forming a loop of material instead of a straight line. This is visible when I'm actually trying to print my design but it's better even better visible in the step of material loading when the material is extruding out of the nozzle to make sure to push out the formerly used material. 

This was the case for my self-made PCL (see-thru) but also for commercially-bought ABS (green), which I also tried. 

Do you have an idea where this problem comes from and possibly also on how to solve it? 

 

 

[MariMakes 178]

Hey @Till187,

 

Often there some material collected near the nozzle but it should start dropping down and become a straight line. 

But if your material keeps curling, than often there is some residu left in your nozzle. 
You can perform the print core cleaning procedure from your firmware to remove any residu from inside your nozzle. 

It's a tricky material to 3D print with. 
I hope some more community members jump in to help out. 

Good luck! 💪

[geert_2 556]

I think you need to keep your nozzle cleaner. I always wipe it immediately after a print completes. If there is stuck residu, I gently (always very gently!!!) scrape that residu off with a very soft brass screw thread, whereby the treads act like a soft file. Never use steel or hardened things, that could damage the nozzle.

 

Sometimes I oil the nozzles when hot, with PTFE oil. This reduces the amount of material sticking and accumulating onto it, but it does not totally eliminate the effect.

 

What can also help against edges or corners lifting, is using a brim. Or use a skirt that is very close to the model, e.g. with 0.1 to 0.3mm separation: that separates easier than a brim, but still helps in keeping corners down. Or for stubborn cases, design a custom brim into your model in CAD, in such a way that it is very stable, but still easy to remove. This may require quite a bit of trial and error, on small test pieces, just to find the optimal concept.

 

Apart from this, I have no experience with your material. Maybe try different glues or adhesion-sheets (like wiping dissolved wood glue onto the bed, tape,...). For my PLA and PET prints, I just *never* use glue..., so I have no idea about your material.