3D Printed parts - Working at depth?

[The Ruttmeister]

"poor interlayer bonding" is basically marketing from SLS manufacturers. Who are jelly about FDM printing in anything that melts and doing it in a fraction of the lead time for a fraction of the cost.

Can FDM delaminate? Yes, if you are doing it wrong (like printing with ABS, which is a garbage polymer alloy that needs to die), but as emoreira says, its not as fragile as people think. Far from it.
Get the material and process right and it will not fail across the layer bond.

Know your manufacturing process and understand how to use it.

 

[saxman242]

like printing with ABS

Yes, ABS is way worse than PLA in this context. About 90% weaker in interlayer bonding with ABS vs 25-30% weaker in interlayer bonding with PLA per the paper "
The Influence of Manufacturing Parameters on the Mechanical Behaviour of PLA and ABS Pieces Manufactured by FDM: A Comparative Analysis" from 2008.

Testing still shows PLA being a good bit weaker interlayer though.

 

[The Ruttmeister]

Yeah, I don't know if they have pointed a student at it yet, but CF filled filaments get much closer to homogeneous material properties, due to their much higher surface area at the contact area.

Like I said, know your process and how to use it. I see far too many people using FDM when they should be using milled aluminum, then complaining that it wasn't steel.

 

[seb13]

I copied the thread from the female thread.

So how did you do that? 3D scanning? Your thread is definitely smoother than mine. I have sharp edges where yours are round and closer to the original design.
Did you used one of the library threads or you created one from a custom vertical profile?

 

[saxman242]

So how did you do that? 3D scanning? Your thread is definitely smoother than mine. I have sharp edges where yours are round and closer to the original design.
Did you used one of the library threads or you created one from a custom vertical profile?

A quick and easy way to replicate threads correctly is if you know the thread profile you're looking for, you can generally find a .stp file of an appropriate bolt on mcmaster.com, and then incorporate it into your part.

 

[emoreira]

So how did you do that? 3D scanning? Your thread is definitely smoother than mine. I have sharp edges where yours are round and closer to the original design.
Did you used one of the library threads or you created one from a custom vertical profile?

It was done with a profile made with parts of circles. I've measured the pitch with ink and a tape, I coat the thread with ink and then I adhere a tape to the inked thread. With this I can measure the pitch.
I have no standard thread profiles loaded to FreeCAD (I even don't know how to do that).

 

[emoreira]

Yes, ABS is way worse than PLA in this context. About 90% weaker in interlayer bonding with ABS vs 25-30% weaker in interlayer bonding with PLA per the paper "
The Influence of Manufacturing Parameters on the Mechanical Behaviour of PLA and ABS Pieces Manufactured by FDM: A Comparative Analysis" from 2008.

Testing still shows PLA being a good bit weaker interlayer though.

I'm using PETG. It has the dimensional stability of PLA, the mechanical properties of ABS and the easy of print of PLA, but with the big PLUS of a greater interlayer bonding.
Of course, tweaking the configuration is paramount.

 

[The Ruttmeister]

Fusion360 has one of the most comprehensive actually modeled threats capabilities (and you can get Fusion360 for free).
Its not perfect, I still have threads I need now and then that are not in Fusion... But its darn easy when they are there.

Some calipers and decent CAD will get you there.

 

[MattAO]

I have printed all my diy scuba parts in PLA never an issue. Ymmv

 

[seb13]

It was done with a profile made with parts of circles. I've measured the pitch with ink and a tape, I coat the thread with ink and then I adhere a tape to the inked thread. With this I can measure the pitch.
I have no standard thread profiles loaded to FreeCAD (I even don't know how to do that).

wow, brilliant!