Filament Choice

[Timmyjane]

I'm sure in the individual thread discussions this has been debated several times but I am wondering what everyone fids to be the best material for scuba parts.
I was under the impression that ABS was a good choice and then I come across a post that says ABS is not.
What is everyone using to make parts that need strength? Parts that are simply seals or under low stress?

 

[davehicks]

How you print can be more important that what you print with. I made some custom wrenches for regulator repair and learned a lot about this. In your slicer crank up the wall perimeters which creates long and uninterrupted fibers that can make a part much stronger.

 

[emoreira]

I print with ABS. I always print with 100 % infill to avoid water ingestion. Besides I print at the highest temperature, 250 °C to ensure good bonding in the Z axis. Furthermore I reduced the distance between lines, as default the distance between lines is 0,48 mm. I've reduced to 0,44 to avoid void spaces. Also I do not use layer fan.
Parts are almost always black. ABS has a better temperture stability. Many times, prints and scuba gear in general, are left at the direct sunlight. With PETG and PLA, direct sunlight deforms the prints.

 

[ScubaToneDog]

It really depends what you are making. There are many different hybrid filaments out there now. I use PLA+ which, depending on the company, is a mix of PLA and ABS or PET that stands up pretty well to UV and the elements. I have some PLA Plus parts I made for my picnic table and boat that have been in 100+ summer heat/sun and below zero in winter. And while they have faded some, they are still going strong. Regular PLA and PETG don't fair well in the heat of the sun. If your printer is capable, there is also POM (aka Delrin), CPE, Nylon and a whole slew of flexible filaments.

The biggest thing is the design and orientation of your part when you print it. I put fillets at all 90 degree transitional stress points. I read a lot of people have 3d printed goodman handle failures. Adding fillets, orienting your part on the slicer at 30 degrees and printing with supports will make the handle very hard to break.

By far though, Nylon with 25% carbon fiber is my go to for anything I need to be functional. Its pricy and needs a hardened steel nozzle, but worth it.

 

[OTF]

PETG is the best "common" filament for general underwater applications. It's easy to work with, recyclable, and achieves excellent strength and layer bonding.

ABS used to be king for this, it's alright, but printing stronger watertight parts is just easier with modern PETG offerings. Consider post dates when researching this stuff online, filament quality/tech/availibility has changed a lot over the last decade. ABS warps and splits like crazy, its always a battle to get perfect prints. Lots of fine tuning. A good heated bed and enclosed build chamber are required, what you really want is an actively heated build chamber but that is very rare outside of industrial printers.

Nylon works fine even though it does absorb some water and swell a little. I've even used it for propellers (which measurably gained water weight, but still worked).

PLA is surprisingly good and shouldn't be written off, especially for prototyping before your final part or anything that isn't intended to outlive you. It's cheap and more environmentally friendly, and not nearly so biodegradable that your parts will dissolve like some people assume. And no, your first print will never be your final version, so do it in PLA first.

 

[ScubaToneDog]

PLA is surprisingly good and shouldn't be written off, especially for prototyping before your final part or anything that isn't intended to outlive you. It's cheap and more environmentally friendly, and not nearly so biodegradable that your parts will dissolve like some people assume. And no, your first print will never be your final version, so do it in PLA first.

If you have a hobby or local store that sells filament, look for their sales on "ugly color" PLA. I picked up some bright red and deep purple 1kg PLA spools for $10 each on clearance.

 

[AJ]

I'm sure in the individual thread discussions this has been debated several times but I am wondering what everyone fids to be the best material for scuba parts.
I was under the impression that ABS was a good choice and then I come across a post that says ABS is not.
What is everyone using to make parts that need strength? Parts that are simply seals or under low stress?

The question is: in what conditions will it be used? Low stress -> PETG, ABS, even PLA, etc. High stress and seawater -> engineering materials like Polycarbonate? The latter is very hard to print, but is one of the toughest materials to use. Many car parts are made of PC.

There are lots of variants between them.

 

[Timmyjane]

It really depends what you are making. There are many different hybrid filaments out there now. I use PLA+ which, depending on the company, is a mix of PLA and ABS or PET that stands up pretty well to UV and the elements. I have some PLA Plus parts I made for my picnic table and boat that have been in 100+ summer heat/sun and below zero in winter. And while they have faded some, they are still going strong. Regular PLA and PETG don't fair well in the heat of the sun. If your printer is capable, there is also POM (aka Delrin), CPE, Nylon and a whole slew of flexible filaments.

The biggest thing is the design and orientation of your part when you print it. I put fillets at all 90 degree transitional stress points. I read a lot of people have 3d printed goodman handle failures. Adding fillets, orienting your part on the slicer at 30 degrees and printing with supports will make the handle very hard to break.

By far though, Nylon with 25% carbon fiber is my go to for anything I need to be functional. Its pricy and needs a hardened steel nozzle, but worth it.

I need to do some studying on part orientation. Got any quick tips or best practices?

 

[DiveDiversions]

Zack Freedman just released a Youtube video going through several types filament types, very informative.

ASA filament would seem to be the best choice

 

[OTF]

I need to do some studying on part orientation. Got any quick tips or best practices?

Generally parts are weakest along layer lines (perfect layer bonding is hard) and when they fail they split between layers. Consider the forces that will be applied to your part in use and try to print them in a way that those forces aren't splitting layers apart.

The other thing you want to do is minimize overhangs that require support while printing - eg. a cup should have the opening up instead of down. Orienting parts on the printer is a balancing act between those two factors.