3d Printing a sheath for my trauma shears.

[The Chairman]

www.Thingverse.com is not getting me there.

Ah... I missed the "i"... Thingiverse - Digital Designs for Physical Objects

Here's a link to their Scuba related projects: Search Thingiverse - Thingiverse

 

[kelemvor]

I've got a gopro mask mount that I printed 3 years ago based on a thingiverse design a few years ago (Easy-Install Gopro Scuba Mask Mount with recessed nut and support by zachnfine) It's printed in PLA. I didn't really like having a gopro on my mask strap so it's only seen about 5 dives. I think the concerns about using pla when diving are overstated.

 

[The Chairman]

I didn't really like having a gopro on my mask strap so it's only seen about 5 dives.

Yeah. Trays are the only way to eliminate the jostle on a GoPro. I've almost gotten seasick while watching footage from a head mounted GoPro.

 

[jgttrey]

You're right and perhaps I should have been more specific rather than just say "biodegradable" which implies PLA would just dissolve or something. PLA will work. But, it isn't the best choice.

It is a fact that PLA is more sensitive to UV, absorbs water and has a lower glass transition temperature and is more prone to softening or sagging if left in the sun. For outdoor applications, ABS and PETG are much better choices, and of those two I like PETG the best because it doesn't stink, is more flexible/less brittle and generally has better layer adhesion, which makes parts stronger.

 

[The Chairman]

has a lower glass transition temperature

Define this.

 

[jgttrey]

There are probably a bunch of experts in material sciences that would take me to task for even trying, but generally speaking 3D printing types use "glass transition temperature" to describe the point at which the material softens - not melts, but begins to lose strength.

With PLA, that happens 130-145 degrees (f). That's why you don't to print PLA coffee cups and why PLA parts can sag if they sit in the hot sun long enough.

PETG can go 30-40 degrees more before it softens. ABS is even a little better, but IMHO is too brittle for some of the things I have printed. PETG flexes and is less likely to snap.

Effects of Temperature on PLA and PETG 3d Printing Filament

 

[grf88]

I have just started to use PETG and although it is a little fussier than PLA it makes for more durable prints. I have not tried ABS due to inadequate ventilation for my printer.

 

[jgttrey]

Agree. PLA is the easiest (most forgiving).

I think PETG is even a little more challenging than ABS in terms of sensitivity to settings. PETG is more prone to be stringy and leave little webs between parts, particularly if the extruder is jumping from place to place. It required some fiddling with fan settings, retraction speed, coasting and some of the other slightly more obscure settings in Cura. Even with that, it is known to be a "stringy" filament. ABS prints more cleanly and is harder, but not nearly as strong as PETG.

 

[guruboy]

Have you considered something PTE based?

 

[jgttrey]

You got me there. I'm not familiar with PTE based filaments.