i’m wondering what the best material would be for an application that snaps together. currently i’m using PLA+ but im noticing after a few cycle the connection starts to get looser and looser. is ther a material that resist wear better than PLA but is still cheap and available in many colors? i’m currently testing PETG but no data to share yet. please keep in mind the parts are rather small so high quality printing is essential.
That’s a great question with a not so simple answer. 90% of my printing is from original designs and many include snaps. You already learned that PLA just doesn’t work well.
I have had some good results with PC and PETG. I suspect that ABS or ASA may work but did not test it because of the fumes issue. While PC can be expensive, it is far more sturdy of all the filaments I use for parts fabrication albeit not very pretty at times. Whereas no 3d filament is perfect for 100% durability, these two filaments appear to be the least problematic.
What you will likely find is that layer orientation will have a far greater impact on durability of snaps. If possible, if you can arrange for the print to go in the direction where the layers are perpendicular to the lines of force, you may see greater durability. And if you are doing your own CAD, add chamfers to the joints to spread the stress out onto the part. Fillets also work but chamfers print better.
Note that getting to the ideal layer lines is difficult and tricky. Often I may resort to splitting the model within the slicer with tabs and then using Acrylic Cement(not glue or epoxy) to chemically weld the plastic together. Then I simply print the two components using an orientation that puts each in the ideal layer configuration.
Here is the best cement for thermoplastics. It has worked to “weld” not glue, every plastic I have tried it on with the exception of silicone.
Nylon. I’ve used this for a lot of mechanical stuff. In my experience anyway, significantly more durable than ABS/ASA/PETG/PC. I’d use it for everything if it wasn’t such a pain to print - always requires drying prior to use…
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really good information you sound like you know what you’re talking about. perhaps if i can alter my dsign to accomadate an easier material like PLA or PETG. would you mind if i private messaged you as the design i’m working on isn’t something i want in the public right now?
Can you share the filament you’ve had the most success with? The “pure” nylons I’ve tried out have been less than stellar but to be fair, they have been industrial grade and my P1P is just inside the hairy edge of tolerance for proper temps.
This is the material I experimented with and had abysmal results. There was very poor layer adhesion and it did not survive any of my stress tests.
When I requested a SDS, they revealed that this is PA66. I haven’t tried out
This is a table I found that highlights the choices in the market. It came off of a technical website and unfortunately, I don’t remember where.
| Nylon Type | Properties | Filament Makers |
|---|---|---|
| Nylon 6 | Strong, durable, high melting point, slightly flexible | Taulman3D, eSUN, MatterHackers, Polymaker |
| Nylon 12 | Flexible, less hygroscopic, good impact resistance | Taulman3D, Sainsmart, 3DXTech |
| Nylon 6/6 | Higher strength, stiffness, thermal resistance | Ultimaker, Taulman3D, 3DXTech |
| Nylon 6/66 | Balanced properties, mechanical strength, easier to print | Polymaker, MatterHackers, 3DXTech |
| Nylon Carbon Fiber | Increased stiffness, strength, reduced warping | ColorFabb, MatterHackers, 3DXTech |
| Nylon Glass Fiber | High rigidity, strength, requires hardened nozzle | 3DXTech, MatterHackers |
| Nylon 618 | Good strength and flexibility, lower printing temperatures | Taulman3D, eSUN |
| Nylon 645 | High strength, translucency, toughness | Taulman3D, MatterHackers |
I had that issue in the past for the phone mount on my motorbike.
PLA is no good as it wears too quickly, great in terms of stiffness though.
Nylon is really good, especially the harder types.
It deforms rather than wearing off.
PETG is about the same and a bit easier to print but does not last as long.
Over time the deformations become more permanent, so I start with a rather tight and annoying fit.
Then, when things works smooth I get ready to print a replacement and have it at hand once the fit becomes too loose to be secure.
TPU95 is my new favourite here.
Needs slightly larger connectors but I just fail to break them or wear them out.
I see no need for fibre filaments in my applications so I can’t comment much of their suitability.
+1 on Nylon or PA. Not necessarily CF Nylon, or GF. Those will go the opposite way from what you want, however, they do make PA easier to print.
Its super durable and relatively tough, and generally will take many cycles of hinging provided they are designed well.
PC, and PETG would be my next choices. I personally like PETG for living hinges and flexures, it’s my go-to and they last a decent number of cycles. But I feel like they do still fall off, just slower.
For snaps, like Olias stated make sure to print them optimally. Never tried TPU as other member referred to, but if designed well, I can see that working well. Maybe even using TPU as a bolt on or glue in second component.
Another thing to manage is the thickness and length of the flexing part. These two aspects have a significant effect on its ability to last. Personally, I like round clasps or locking features, they don’t hold super tight, but they generally give a better feel when opening and closing (less resistance, but still a positive detent). Play around with the various aspects and see what you like.
Funny how getting into hardware store brings back memories of this problem…
I found ‘cable clamps’ of the stick on kind - with a nifty snap mechanism.
Like a double hinge system, not unlike those articulated wheels.
And on the pack it said ABS, not Nylon or such fancy stuff.
Indoor use only of course LOL
The design made me wonder a bit as it seems extremely basic.
The snapping power is provided by large sections of the clamp.
The hinges basically just anchor points with surprisingly little movement.
Take a look:
As you can see the design is rather clever indeed.
Closed the left arm folds over and pushes against the right arm -with a proper fit of course.
The middle part folds down using those three hinge points.
It should not be too hard to replace the left arm with a copy of the right one.
That gives a perfect inner space to grab things while the open arms provide the grip strength.
The one pictured is the “long life” Nylon version, the China shop in town sells them in cheap ABS but identical look and of course no 3M tape on the back LOL
If you design the arms and snap in part to flat at the top it would take quite some force to get them apart.
So a release finger like on the original for both arms would be advisable…
Just thinking - and it seems to confirmed that Nylon is the way to go, not TPU after all.