Advanced filament question
Working on a project and I need a strong, stiff and chemical resistant filament. PLA is stiff but not chemical resistant and will be affected. PETG is resistant to chemicals, but like ASA, is not as stiff as I need it, even with 20% fill and 4 perimeters. I can bend and twist 6x75x15mm sample prints in my fingers.
I have read that Nylon and Carbon Fiber filaments have some flexibility to them. I am looking at polycarbonate filament but I have not seen anything on stiffness. Need to minimize any flexing due to forces on the print.
I have read many articles and watched videos but they all talk about strength, not stiffness. Think of a beam with a camera on the end and not wanting the camera to shake around due to material flexing. Exposure mainly to alcohols and oils. Some exposure to acetone and other solvents.
I will try printing it myself but will send out to be printed in metal if I cannot find a stiff enough material.
Have a MK3S+ with enclosure. Have printed well with PLA, PETG and ASA. Time to take the next step.
RE: Advanced filament question
I can only share my experience, not give a definitive answer. But I have tried different materials on my trusty Ender 3 S1. PLA, PETG, PETG-CF, ASA and PA12-CF (nylon). All without an eclosure, but be ware of draft, and fumes. The CF materials are really stiff, though not as strong as their normal counterparts. However, the PA12-CF was very strong and very stiff. The Pa12-CF is quite expensive, but could be worth a try. It also printed nicely, but need good drying (though it is less hygoscopic than PA6), and a proper print pofile.
What was difficult with the nylon was clean prints with support. A bit messy after the supports was removed. Without supports, it was very good.
This is my two cents, I hope others chime in with some advice as well 🙂
RE: Advanced filament question
Yes, carbon or glass fiber filaments are very rigid. Possibly PC-CF would be stiffer than PA-CF, but all the parts that I have printed in Prusament PA11-CF are stiff enough for me. Chemical compatibility is another question. Nylon is usually better than Polycarbonate but it depends on the kind of solvents that the filament must endure. The following link is very useful for checking this matter:
Experiment with CF. The stiffness varies depending on lay of the filament so young's modulus figures are meaningless, you have to measure the result from your component and if it is not as required adjust the slice and try again.
Cheerio,
RE: Advanced filament question
Hello and thank you for the suggestions.
Erik, you suggestions are taken into account. Drafts are not an issue. I am using an enclosure. A lesson from the early days at work when prints were failing all the time due to drafts. Printer was put in a cardboard box and was still in the box almost a decade later. I have exhaust ventilation at the enclosure. RH in my workshop is about 25% @18 degrees, which is lower than many recommendations for filament being dry. Storage boxes are at 11-15% Cost of the Pa12-CF may still be cheaper than other options.
Artur5, it looks like a CF or glass filament will be needed. Thanks for the link to compatibility. I forgot about the compatibility lists. Will look.
Diem, I will do some experiments. Options are, 3D print at home, 3D print out of metal by on-line site or machine, which will get very expensive. One thing it took me time to learn when I got into 3D printing is the cost of material is not as high as expected. I used to try skimping on wastage and testing when I first started, now I do tests all the time.
Now to check sites and order some CF filaments. I will have to slice my models to see how much filament I am going to need for this project. Two drawings left to complete. If they are stiff enough, may cut out some planned CNC work. Ordering Prusa Filaments in Canada is expensive due to the added shipping charges.
RE: Advanced filament question
Have you thought about adding metal rods?
RE: Advanced filament question
Good suggesting but it won't work. Very hard to connect things to metal rods. 🙂 There are metal rods in the system, and the 3D printed parts are going to hold the metal rods as well as other things that need to move on the metal rods. I am using 6mm metal for all the flat pieces. I was thinking of mixing 3D printed and flat metal for the other parts but if I can print then it makes things smaller and easier. Metal rods do not provide 3 directions stiffness. Only in one direction. Forces are in three different directions.
The 3D printed parts are all the connecting pieces that are not easily made with a basic metal router. Rough calculation today is about 500g of filament to print one iteration all the parts. Just about to place an order for some ASA and PETG carbon fibre filaments as well as hardened nozzles. I do know that before I go ahead with the project, I am upgrading all my PETG parts on my printer to ASA.
Since posting this, I have read about carbon fibre based filaments and how stiff they are.
RE: Advanced filament question
Take into account that ASA, ABS, PETG and PC aren't compatible with acetone !.
RE: Advanced filament question
I print rocket nose cones out of PA-CF, PC-CF, PC Blend CF. The PC cones are significant stronger in a tough landing but both are strong. PETG-CF and PLA-CF are more prone to shatter. I have not done strength testing but my observation give a slight edge to the PC. Then again, PA-CF gas been easier for me to print.
Yes, carbon or glass fiber filaments are very rigid. Possibly PC-CF would be stiffer than PA-CF, but all the parts that I have printed in Prusament PA11-CF are stiff enough for me. Chemical compatibility is another question. Nylon is usually better than Polycarbonate but it depends on the kind of solvents that the filament must endure. The following link is very useful for checking this matter:
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Chuck H
3D Printer Review Blog
RE: Advanced filament question
I have tried Prusament PETG with acetone and didn't see any degradation. It was a quick test for smoothing, not a soak. Will do some soak tests in the future. Solvents and oils are more from spray than soak.
Having never printed with more than PLA, PETG and ASA, and the time constraints, I will start with ASA or PETG CF filaments. If they work out, then I will step up to PC which is on my list. Will be improving the insulation on my enclosure for future printing. Found it made a nice difference on warping with ASA. I am not worried about direct hits. Vibration and maintaining alignment under stresses are the key factors in this project.
RE: Advanced filament question
in my experience, acetone vapors smooth and strengthen a print.
Take into account that ASA, ABS, PETG and PC aren't compatible with acetone !.
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Chuck H
3D Printer Review Blog