You should be printing in PCTG. I have, and let me tell you about my experience.
Hardly anyone knows about the wonder material that is PCTG. Chemically, it’s actually PolyCyclohexylene Dimethylene Terephthalate Glycol-modified. It’s a copolyester derived from PETG (Polyethylene Terephthalate Glycol) with one key difference: it uses cyclohexanedimethanol (CHDM) instead of, or alongside, ethylene glycol.
Everyone in the 3D print space has heard of and has probably used PETG. It’s an increasingly popular 3D print material, as it offers better strength and thermal resistance than the more popular PLA, but also prints far easier than ABS, ASA or PA.
As you might guess, PCTG is as easy to print as PETG, which is very straightforward. I might even say that it can be easier than PETG in my experience.
I have used PCTG on occasion, but this week I had a situation where PCTG was actually the best material for the job. I needed a replacement skimmer basket for a pool, and normally one would trek over to the pool store and pick up an outrageously priced replacement.
Having a fleet of 3D printers at my disposal, I thought I should simply make my own. My first problem was designing the basket. This would be a little bit of work, as I could simply measure and echo the original broken part.
Perhaps someone had already done this? A quick search found this design on Printables by contributor Ivosus, which was the exact model required for the pool. No design work required for me, in that case.
The next issue was selecting a material to print the basket. I did print one using PLA just as a fit test, since it would have to successfully be mounted. However, PLA was certainly not the best material for this application.
The basket will be outside, withstand a range of temperatures, be constantly underwater, and literally hold sticks of caustic chlorine. Those are conditions not every 3D print material can withstand.
My first thought was to use ASA, a relative of ABS that is more resistant to outdoor UV light. However, it’s pretty hard to print, and this is a rather complex design. Then I saw this comment on the Printables page from Jens Wensing:
“I printed it, it came out nice, only issue… after using 1 week it dissolved. I used ASA for print, so not sure what is wrong.”
OK, so ASA is out. What’s next? The page recommends PETG. However, it turned out I didn’t have enough PETG on hand to print the basket. Could I use PCTG instead?
PCTG will be stronger than PETG, have reasonable UV resistance, and should have better chlorine resistance than PETG, all while being easier to print. I made the decision to use PCTG for this application.
The next problem was that basically no 3D printers come with stock print profiles for PCTG materials. PCTG is so unknown that it doesn’t even appear in most software.
I printed the basket’s parts (which snap together) on my Anycubic Kobra S1 using Fiberlogy Translucent PCTG. As there was no PCTG print profile in the Anycubic software, I had to take special action.
I duplicated the stock PETG profile, and then manually edited it to match the characteristics found in some PCTG profiles online. However, the Anycubic software would not let me save it as “PCTG”, so I had to fake it as a special PETG profile. Even worse, the Kobra S1 must have its spool inputs defined at the machine, and there is no option for PCTG. When you dispatch a job to the printer, it checks to ensure your slice (PETG) matches the material mounted on the machine (PETG). I had to use fake PETG at both software and machine in order to get this to work.
The results, as you can see in the images, were impeccable. The prints were absolutely perfect. No stringing, no messes, smooth surfaces and crisp detail. All prints worked the first time without issue. That is easy 3D printing.
I won’t know if the material lasts, but according to Ivosus, it should last at least a year because PETG parts have done so. Perhaps it will last even longer because it is PCTG.
My experience reinforced the idea that PCTG is the ideal 3D print material for FFF devices. It prints easily, it’s far stronger, looks great (even translucent), and offers better thermal and chemical resistance.
Why wouldn’t you use PCTG?
Well, there are three reasons, all of which should go away at some point.
Reason one: Sourcing. There’s almost nowhere to find PCTG spools. The two most prominent manufacturers are Fiberlogy in Europe (the material I used), and 3D-Fuel in North America. Typical filament outlets don’t offer PCTG, at least not yet.
Reason two: Cost. It’s a bit more expensive than other materials. Money talks, and perhaps that’s the major reason PCTG is not as popular as it should be. However, if sales volumes increase, then we should see the prices fall.
Reason three: Support. 3D printer manufacturers do not properly support PCTG. Their software and hardware usually don’t include it as an option, and there are few print profiles available.
All of these issues can be easily resolved if the parties involved simply adopt PCTG.
Let’s do PCTG. It’s a better material.
