So I have been working with silk filaments for a few weeks now. It has been a frustrating journey, and the interwebs was not a whole lot of help on figuring out how to work with this specific material. Most of the posts that I found on the mater had widely differing views on what settings were needed. Some said go hot, some said go slow, but nobody could agree on what worked, or even state what worked. I am going to try to do that.
I have been working with Inland Silk Violet and CooBeen Gold/Silver/Bronze/Copper filaments. I had many many failures with the CooBeen material. One failure was bad to the point that I had to spend 45 minutes digging melted plastic out of the nooks and crannies of my printer head. If you look closely below you can see bits of the rubber cover from the print head in there. It was a spectacular fail. But I learned from it. Do not leave unattended!
The problem with this material is that it reacts similar to a PETG mixed with a PLA. There is an elastomer additive in the material that helps give the material its shine, but can also cause a good amount of stringing. Because of this I have found that the material needs to be heated to a temperature higher than for normal PLA. Normal PLA I generally run at 203°C. This silk material I have found needs to be run at a high temperature depending on the machine and the specific material. I am working on an Creality CR-10 V3 with the standard setup as well as Cura 4.8 as a slicer.
Look at all those cute little failures. Most did ok, until it got to the thin parts on their ears. That is how I new there was something going on with the temperature. On the gold little monster there was a good amount of under extrusion in the middle of his head, but the over heating when it came to his ears. Isn’t just an adorable little mutant bunny. Layer adhesion was also a tricky thing to work out. Turns out fan speed and flow rate plays a huge role in that. I also learned that room temperature where your printer is was massively important. The space where I have my work studio was not exactly the best at having the heat it. It was so cold in my studio that I was wearing an extra blanket all the time. There are ways to counteract that room temperature problem. You have have your entire machine – including the filament roll – in an enclosure. This will help you regulate that temperature fairly well. You can also build a Heated DryBox (link). Warming the filament could really help improve the quality and consistency of your prints.
Nozzles and Layer Height
I would not recommend using smaller the a 0.4mm nozzle. I tried with a 0.2mm and a 0.3mm and found that I could only get two to three layers to print before it clogged. I had far less clogging issues with the 0.4mm nozzle. You need to have a minimum of a 0.2mm layer height for it though. It will clog at shorter layer heights.
The best nozzle size I have found for this material is a 0.5mm nozzle. Then you can work with as low as a 0.16 layer height. I have not had a single clog or failure since I went to the larger nozzle size.
Temperatures and Speeds
For the bed temperature I would stick to around 55º. Less than that and you risk no adhesion what-so-ever. More than that and you risk having your part come unstuck in the middle of your print.
For the nozzle temperature I would recommend between 213-218º. On smaller more detailed pieces I would go with the lower temperatures. If it is too hot and not cooled fast enough you get material layer build up at the corners, as shown below.
This is also why you need to keep an eye on your fan speed. You do not want it too high or the layers will not stick together. You do not want it too low or you will get the melting seen above. I have been working with about 40% fan speed. Then I also do minor – maybe ±3% – depending on where the print currently is at.
As for print speed… I was doing an overall speed of 40 mm/s with an infill speed going a little faster at 50 mm/s. I did slow the outer layers down to 20 mm/s. This was to make sure there was no gapping or under extrusion in that area. travel I left at the default of 120 mm/s.
Infill, Supports, and Bed Adhesion
I would definitely recommend a minimum of 8% infill with the material. I typically print hollow objects – to save time and material – but you really cannot with this material. Not unless what you are printing is rather small with little overhang. Then you can get away without infill.
Supports may be needed. I found that my prints turned out better when I added a little extra support to anything with more than a 50° overhang. and then I only went with what was touching the bedplate. Too high of a risk of supports sticking to the part and not being able to get them off is using more than that.
I almost always print with a brim. It allows me to monitor the leveling on the bed before the print begins and make small adjustments if needed. For this material I bumped the brim from 8mm to 16 mm. I did this to make sure that there was enough stuck to the bed to avoid the possibility of the part becoming detached during printing.
I highly recommend downloading a temp tower to get your temperatures and fan speeds in line. Everything else is trial and error. Print smaller things until you think you have it right then size up slowly. Needs can change depending on the size of the part you are making and how much detail it has. Be patient and don’t give up if something fails. Tweak settings little by little and everything will dial in. Good Luck!
The Settings I Use
These are the settings I ended up finding to work the best for the silk filaments. Feel free to contact me if you want to talk about anything here. Always happy to collaborate on things.