How to 3D Print with Industrial Strength Nylon
Written by Justin R. Shook on November 4, 2015.
This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.
CAUTION: Always use the proper safety equipment when working around 3D printers. For this tutorial, use safety glasses and gloves.
Nylon is an impressive and exciting material for many reasons including its strength, impact resistance, and availability in several different alloy mixes for FDM 3D printers. Adding nylon to your maker arsenal can really widen your available applications ranging from gears to prosthetics. Unfortunately, nylon exhibits hygroscopic (water absorbing) properties and poor print bed adhesion/warping under certain conditions. I’m writing this guide to help take out some of the mystery and frustration in using this material. I’ve gone through a few rolls of Bridge Nylon and documented some of key points to consider.
- 1Elmer's Craft Gluestick
- 1Bridge Nylon Filament
- 3D Printer
- Digital Calipers
One problem that will stand out right away is intense bubbling and crackling during extrusion. The picture above shows bubbling nylon out of the extruder with some clean nylon lines extruded on the build plate in the background for comparison. This happens because water is literally boiling in the extruder as you’re printing or your hot end temperature is set too high. The boiling temp of water is roughly 100C and this material extrudes best at temperatures in the range of 240-250C. If you notice this issue, stop your print right away and save your material. If you let the print run regardless of the moisture issue, you seriously compromise the structural integrity of your print due to all of the bubbles present in the layers. In addition, the finished print looks like compressed cobwebs. Not a good look unless you’re trying to make a mummy costume.
The solution to this issue is drying your filament out. The easiest way I’ve found to do this is to place the roll of Nylon in the oven @ 180 F for about 7 hours.
Rather than reacting to this issue though, it’s best to prevent it from happening in the first place. There is a plethora of different filament storage solutions online, so do a little searching and I'm sure you'll find something that works for your application
Bed Adhesion and Warping:
I was printing out a prosthetic knee socket on my Lulzbot Taz 5 3D printer only to find unacceptable warping about 10 hours into my 21 hour print. If you run a 3DHub or other 3D printing service, the last thing you want is to deliver a part to a customer with a bad warp defect. Whether you have a PEI or glass bed surface, you’ll want to go to your local craft store and grab the large stick of Elmer’s Craft Glue. Believe me when I say I’ve tried just about every type of glue stick and spray. Just go with the Elmer’s.
From what I’ve read, most non-toxic glue sticks contain PVA which causes the “stickiness”. I’d like to see more of the science on what actually causes the bond from a chemical perspective though. If you have some good information, leave a comment! When you apply the glue to the print surface, be very meticulous in consistently covering the print area you’re working with. I use the "lawn mowing" grid method for application. You should only need one pass with some slight overlap.
Last but certainly not least are the print settings. I thought it would be a good idea to publish some settings I found to be successful because I saw some misleading information on forums and even 3D printer manufacturer websites. I understand 3D printers and extrusion systems vary widely, so only use this as a point of reference (I have an Ultimaker 2, Lulzbot Taz 5, and Prusa i2) and experiment as needed.
|First Layer Speed||20 mm/s||Speed||40-50 mm/s|
|Ext. Temperature||240 C||Bed. Temperature||45 C|