Good Idea? Silicone oil on the nozzle
So, I had some difficult filaments to deal with in recent times, and I also had to print some objects with three perimeters. The combination of both factors resulted in a serious problem with filament build-up on my nozzle - not much sticks to the Obxidian, but when it's enough, there will be blobs.
This really stressed me out and after some failed prints I had an idea. I first cleaned the nozzle as usual, hot and with a brass brush. When the nozzle was clean, I put some silicone oil on my brass brush and spread it over the nozzle. Nothing sticks to silicone, that's why we have the socks - maybe this would help?
Well, it seems as if the idea wasn't that bad. Since I applied the silicone, not a speck of filament has stuck to my nozzle. I also tried the awful filament that stuck like crazy before, but nothing. The nozzle is really, really clean.
I don't know if any drawbacks will show up with time. For now, this is an absolute game changer, IMHO.
RE: Good Idea? Silicone oil on the nozzle
Just think what that silicone will do to a print if it contaminates it.
I see filament stick to the nozzle but it hasn't ever caused an issue. Perhaps you have stringing issues more than nozzle clinging?
I just brush off the nozzle before a print and it works just fine. I keep the same spool of PETG on the printer until it runs out and haven't ever dried any PETG. Am I just lucky?
RE: Good Idea? Silicone oil on the nozzle
Well, the way I apply the silicone, I don't see how it could end up on the print. It's really just a very, very thin coat on the nozzle.
The material buildup does not come from stringing, I actually have that under control. As far as I can tell from looking really hard at hours of camera footage, the material gets picked up by the nozzle while printing perimeters or large surfaces.
Apart from that, I do always print out of a dryer (even my PLA) and I typically clean the nozzle before every print. For certain combinations of filament and model geometry, this was not enough, though.
RE: Good Idea? Silicone oil on the nozzle
What product did you use?
How long do you think it will last?
Interesting idea. I might try it before a really long print or on a multi-material job.
RE: Good Idea? Silicone oil on the nozzle
I used the stuff from Caramba ( https://www.caramba.eu/produkte/silikonspray/), but I guess that brand is more of a German phenomenon. There's nothing specific about it - any silicone spray should do.
I really don't have an idea yet how long one application will work as I only applied the stuff once. I would say that it has survived about 20 printing hours so far.
RE: Good Idea? Silicone oil on the nozzle
Interesting idea.
It says it's working temperature is -30C to 200C so maybe it is okay for PLA, but with anything else may be a problem such as it starts to decompose?
See my GitHub and printables.com for some 3d stuff that you may like.
RE: Good Idea? Silicone oil on the nozzle
Well, the stuff I printed with the silicone is Prusament PC Blend Carbon Fiber, so even if it shouldn't actually help (which is entirely possible), it does at least not seem to cause additional problems.
RE: Good Idea? Silicone oil on the nozzle
I am currently printing the Nextruder parts from PC-CF, and I used that for a little test. Before the print started, I applied a fresh coat of silicone and I watched closely if anything unusual happens.
After 3 hours of printing at 285°C nozzle temperature, I did notice a very faint smell of silicone oil. It was gone again after a few minutes, the print wasn't impacted in any way and the nozzle is still perfectly clean. I'd say that everything in that spray that could possibly evaporate or break down is gone now - let's see if the nozzle stays clean for the next 2 hours of printing. 🙂
RE:
I have some blobs on PETG with custom gcode to take a time lapse videos (which effectively forces print head to move to press a button and during that a bit of PETG oozes out even if well dried), and nozzle X helped in that matter but only to the extent.
So maybe silicone could help a bit more ...will check in about over a week.
If not gonna work then time to mout small brush next to the place where he print head moves.
See my GitHub and printables.com for some 3d stuff that you may like.
RE: Good Idea? Silicone oil on the nozzle
The Nextruder print completed without any issues (and a very clean nozzle), and the parts look perfect - this is PC-Blend Carbon Fiber, so obviously the high temperature does not create any side effects that mess up the print. I guess this concludes the phase I clinical trial, thus establishing that the procedure is safe.
I guess I'll have to try a print with the worst blobbing filament I own, the awful Amazon Basics grey PETG, to establish if it actually helps with the blobs beyond any reasonable doubt. 🙂
RE: Good Idea? Silicone oil on the nozzle
Try printing 2 parts, one with and one without the silicon and test them for strength. See if the silicone has any effect on the interlayer adhesion.
RE: Good Idea? Silicone oil on the nozzle
Fun fact: I did that. Not on purpose, but one of the first test prints for my Sunlu S2 Skadis Mount was a part of the rods. The first print did not have the silicone and actually triggered the idea because of a blob at the end of the print, the next test print was with silicone oil on the nozzle.
As the reason for the test was to find out if the rods would be strong enough for the application, I actually broke them in half. Both were much stronger than expected (I love PC Blend CF) and there was no difference I could have detected without measuring gear.
Also keep in mind that the actual amount of silicone that ends up on the nozzle is tiny. I changed from using a brush for application to using a cotton swab because the brush sprayed little droplets around like crazy. The amount of oil on the swab is "a tiny droplet", and only a fraction of that actually ends up on the nozzle surface. What stays on the nozzle creates a thin film that is really quite hard to remove, and I would not expect that any kind of polymer is a working solvent for silicone. If it was, silicone socks would be a very, very bad idea...