I’ll soon be printing a largish set of radius gauges which will be used outdoors and will get exposed to all kinds of weather. They need to be tough enough for real-world usage (e.g. they will get dropped and/or tossed about).
I have both ASA and PETG-CF on hand and, being quite new to 3D printing, can’t decide which would be the more appropriate. Can someone please tell me which of the two filaments you think would be the better choice, and just as importantly, why?
Please, I’m not interested in other filaments, which I don’t already have and while I do have PLA I know that would be a a very poor choice for this job.
Fibre-reinforced filaments (like PETG-CF) should be handled with gloves which can make them annoying to use for tools. Small particles of the fibre get into skin etc.
Hence I would use ASA.
However, the dimensional accuracy of fibre reinforced filaments is better (they shrink less) but this can be overcome with print calibration or just scaling and reprinting.
Thanks for the quick response. I know that PETG in cars can at time be problematic but that’s really not a concern for me. However, I didn’t know that fibres might separate from the printed item and that most certainly is an issue for me, as I normally only wear gloves when welding and grinding, never for woodwork. Thanks for that.
You’ve made my choice simple; ASA it will be.
Because I create the gauges using a FreeCAD macro I’ll look up typical ASA shrinkage rates and incorporate an adjustment into the macro and just have it generate a new set of step files.
EDIT: After a brief search for the shrinkage rate I think the best idea is just print one or two of these gauges and measure them after at least a day, just to ensure they’ve settled to their final size.
There have been a few threads here about CF bits and folks have posted micrographs showing ends of fibers sticking out of the plastic that can get broken off when the parts are handled.
But it seems to depend on the plastic and even manufacturer how big of an issue it is.
The discussions here tend to get derailed when someone points out a danger and there are sensationalist videos on youtube with people screaming for likes and views. It’s hard to tease out the truth.
But what is true is if a part can shed carbon fibers it’s dangerous. They are tiny and if inhaled can cause lung irritations that can eventually turn into cancers.
People have stuck tape on CF printed parts and when removed has fibers stuck to it.
(Added after being marked as solution - I’m not trying to prevent use of CF filaments. I don’t have a dog in this. But since there is discussion I found those articles which discuss it. Everyone should make their own decisions based on use, audience, or anything else relevant. Those articles at least give points to consider that people can use to decide for themselves if it’s the right decision. If anything, just raising the flag that the issues should be considered.)
As I already have emphysema I’m rather concerned about these kinds of dangers and will play safe if there’s even so much as a possibility of risk. And before anyone asks, I am aware of the problems with ASA fumes and have built an effective fume extraction and filtration system to deal with it.