When it comes to 3D printing filaments, PETG is probably the third most popular material behind PLA and ABS. It is generally easier to print than ABS, but has a higher heat deflection temperature than PLA, making it very attractive for a variety of applications. I’ve worked with several brands of the material and I’m excited to review BigRep’s PETG, so let’s get to it!
PETG has good transparency and is widely used in lighting fixtures, so I chose to work with their Clear offering. The filament itself is very clear and very tightly wound. It was easily loaded with the CPE setup on the Ultimaker S5 (Ultimaker is one of the few brands that refers to PETG as CPE). All objects were printed with an extrusion temperature of 240 °C and a bed temperature of 75 °C. A regular bed glue is needed when printing PETG on a glass bed because PETG can stick so badly to glass that it will break the bed when trying to remove parts; the glue serves as a part release interface that protects the bed. For the same reason, it’s important to allow parts to cool completely before removing them from the build plate. Let’s see how Benchy turned out.
This was printed with 0.15mm layers and it looks great. The transparency hides some of the details, but they’re definitely there, and it’s easy to see that the walls are incredibly smooth. The pillars have sharp corners and the chimney is clean. I like the glass look, but that’s just my opinion. The all-in-one 3D printer test is as follows, also printed at 0.15mm.
I knew PETG was good for overhangs, but I didn’t know it was that good. If you look very closely, you can see the distinctive step effect at the bottom of the arc up to 80° overhang. Most materials start to lose definition around 65°, so this is amazing performance. The rest of the print is also very good. The pillars are straight, the top surfaces are solid, and the corners are sharp. There are a small amount of ropes between the pillars, and the bridges are somewhat sagging, so let’s investigate that further with the Bridge Test.
It’s actually a pretty good bridge at 50mm, considering that the 15mm bridges in the previous test sagged. That tells me that bridging results with this material can be improved by adjusting some print parameters. Remember, the default settings are used in these hotfixes for consistency.
To see how this material would hold up to heat, a rectangular bar was printed, measured, annealed in a furnace, and then measured again to see if it would shrink or expand.
- Original dimensions: 20.5mm x 120.45mm x 5.88mm
- Dimensions after annealing: 20.49mm x 120.42mm x 5.88mm
There are basically no changes, so parts printed on this material should work well outdoors and in warm environments. This is good to know given the use of PETG in lamps that generate heat.
Layer adhesion was tested by printing three vertical drawbars and loading each one until they broke. They were broken at 132 pounds, 124 pounds, and 112 pounds, for an average of 122.6 pounds. Wow! That’s the highest number I’ve seen for this test by a healthy margin. The Z axis is often the weak point of FDM prints, but this PETG’s phenomenal layer bonding really strengthens that typical shortcoming.
When it comes to displaying material that has superior optics, there really is only one option. A lightsaber.
To get that signature glow effect with a 3D printed lightsaber, print the blade on a transparent material and shine a colored LED through it. The gloss will not only be brighter than what you would get by printing a colored sheet and shining a white light through it, but it will allow you to make the sheet any color you want. PETG is an ideal choice for this because it diffuses light brilliantly. And because I already knew it had good layer adhesion, I was able to print the telescoping sheet with single perimeter walls to allow the maximum amount of light through without having to worry about the strength of the sheet. It is strong enough to open and close. The grip was printed in PLX.
BigRep’s PETG is a high-quality offering of the versatile material. Although it prints at a higher temperature, it is quite easy to print with. I experienced no warping or peeling on the printed parts and each object came out fine, although some had a slight thread that was cleaned up with minimal effort; adjusting the retraction a bit would probably solve the problem entirely. When it comes to overhangs, this is as good as it gets. be able to print steep overhangs allows users to print more complex geometries and eliminate the use of support material, saving time and resources. He high heat deflection temperature opens the door to many functional applications, and the strong coating adhesion extends its functionality even further. And it’s a fantastic lightsaber. What else do you need?
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