Concept 3D print materials and production questions

[Sean Crees]

I am not looking to make an entire case with 3d printing, but i was thinking about having the internal structure that components bolt to be 3d printed. I've seen a few people do SLS Nylon for cases and case components. Is this the best bang for your buck option?

I went to https://www.craftcloud3d.com/ and uploaded what i have and one day SLS Nylon was like $100, but then i went back, with the exact same model the next day and it was like $10. Anyone know why the prices were vastly different from one day to the next on this site?

Also, I was planning on using brass heat-set inserts to get solid threads to screw into. For the motherboard, would it be better to screw a standoff into the insert then screw into the standoff, or could i just build a little plastic standoff with the brass insert and bolt the motherboard straight to that?

 

[Napybara]

Nylon is strong material in comparison to other plastic materials. And it is not really the cheap option.

Not sure how big your planned case is, but 100$ sounds more sound than 10$.

The cheapest to print is basically PLA, not that strong and quite easy to melt.

3D printing case I would go for Polycarbonate and PETG.

PETG glass transition temperature is about 84C, PC is about 105C.
PLA is 60C, Nylon about 68C.

 

[Shatrod]

I 3d print a lot and have used threaded inserts. Basically I second the PETG print although nylon is also good. Although from my experience PLA would be just fine with adequate airflow. If fans are always exhausting air it shouldn't really reach 60c inside the case. The only problem spot will be the gpu mount where it touches the plastic. That area will get hot and likely deform PLA.

For threaded brass inserts that are heat set, you MUST use this if you want reusable connections. Basically if you plan to unscrew and screw in new parts more than one time ever you have to have the metal thread. BUT just printing a hole and screwing into it directly is very strong still... Once. If you never plan to remove that screw then the threaded inserts is not necessary. I would put motherboard standoffs directly into the plastic and never remove them. You can still unscrew the motherboard from the standoffs... But treat the standoffs themselves as permanent. For say a gpu mount, use the threaded inserts.

Be weary that 3d prints shrink when they cool. So if you have a 3.5 mm hole (for a standard 6-32 screw) it WILL print smaller and your screw won't fit. You must oversize your holes in your design. By how much is printer and plastic specific. You pretty much have to experiment. Also you will want thicker walls (printer setting not necessarily design constraint). 3d prints are hollow mostly and usually the failure point is not the thread itself but the entire cylinder breaking out from the infill.

I would say it's worth getting your own printer. Something small and cheap to experiment with. Designing for printability is tricky in itself. It's not magic not all models can print cleanly.

 

[Kilrah]

Another simple method if you have the room is to just embed a nut, make it tight so it holds in place:

On my case I printed the motherboard tray in PC, and the rest in PETG.

And yes it's good to have your own printer, if only to print your parts out of cheap PLA to check fitment before you go with more expensive materials or 3rd party services. There's always that mm here or there that doesn't quite fit as expected...

 

[Napybara]

Another simple method if you have the room is to just embed a nut, make it tight so it holds in place:

On my case I printed the motherboard tray in PC, and the rest in PETG.

And yes it's good to have your own printer, if only to print your parts out of cheap PLA to check fitment before you go with more expensive materials or 3rd party services. There's always that mm here or there that doesn't quite fit as expected...

I do the nut embedding as well, just have to give it bit try here and there as for example for M3 nut which is 5.5 wide I have to give it 5.56 space. If I give less the material tends to crack on small areas. If I give it more, the nut tend to fell out.

 

[Sean Crees]

I figured out the price difference. The website defaults to mm for models, and i built mine using inches, so it was calculating the price for an item that was 1/25th the actual size.