Filament advice for high strength part
I am new to 3D printing but would like to replace a latch that holds a deck hatch secure on my sail boat. the part will be inside the boat and is where the handle for the hatch locks onto the deck to hold it securly shut.
I have a MK4 and hardened nozzle.
I am thinking a carbon fiber based filament but I'm just not sure. I've read all of the details on the different filaments sold by Prusa but still not sure which would be best suited.
Thanks in advance for any advice!
RE: Filament advice for high strength part
hi, i got the Prusa PETG PC the other day and i'm very happy with it. Prints very easy and the strength of the parts is very good. Its so much stiffer than normal PETG.
Only did i raise the flow to 1,1.
Of course an other questions is, how strong is the layer bonding, if you have a part that puts stress there too.
RE:
Intuitively I would go with ASA. Should do the job as described. I'd stay away from PC-CF, which is a wonderful, strong filament but also very inflexible and I don't think would work well as a latch. Maybe PETG-CF which should preserve some of the flexibility of PETG, but I haven't used it myself (even though I have a spool of it lying around).
Formerly known on this forum as @fuchsr -- until all hell broke loose with the forum software...
RE: Filament advice for high strength part
I'd go for straight PC and print a couple while you are at it. No print will quite be as strong as a solid injection molded part, but you can probably get close enough.
I've had poor experience with ASA -- the layer adhesion hasn't been that good in my experience.
PC-CF is awesome to print with (doesn't warp), It's layer adhesion isn't quite as good as straight PC, but I was never able to print straight PC until I got my enclosure
PETG might be just fine (and is an easy place to start)
Nylon and nylon-CF are cool materials, but annoying to print. Filament has to be really dry, need an enclosure to get really nice results (for me at least)
I would strongly consider TPU. The higher hardness stuff isn't too difficult to print and the layer adhesion is so good that it's effectively un-breakable. Be sure to put glue stick on the bed though.
Good luck
What are the expected stresses and in which directions..?
Maritime 3D printing differs from longshore 3D printing as much as shipbuilding differs from housebuilding.
Will the part be subject to continuous varying stress or sudden shocks? - PETG and nylon are candidates due to inherent toughness.
Must the part flex slightly under stress or remain rigid? Added carbon fibre dramatically increases stiffness.
Can you orient the print so that the significant stresses run along or across the lay of the printed fibre? This is inherently stronger. If the larger stresses tend pull the layers apart the part may fail early - consider splitting the part into sections and printing each in an optimal orientation then joining them post printing. If this cannot be done print slower and hotter to ensure good interlayer adhesion.
Will the part be exposed to sunlight? UV destroys many plastics, choose one with a high percentage of reflective pigment or paint it - we all know that it's paint that keeps boats afloat... or use a UV tolerant filament (I have been using 3D Tomorrow's Bio-Pro for maritime engineering parts and it survives well.) Be aware that CF filaments are also sensitive to UV as it's the carrier plastic that is attacked.
Will the part be subject to extremes of heat and cold? Mechanical characteristics change significantly with temperature - put a prototype in the freezer then test it to destruction before committing to it.
Think defensively - I use a lot of printed parts at sea and they can be better than the parts in the chandlers - but apply the standard seaworthiness tests. In this case: If you lose a hatch cover in a heavy sea your problems are going to get a lot worse very quickly. How could that happen and how could you design the part to counter it?
Cheerio,