adding metal screw inserts to 3D prints

Dosobye

Limp Gawd
Joined
Jul 29, 2010
Messages
400
Hello,

I am just getting into 3D printing and I'm looking for your experience in adding inserts to 3D prints. I have access to FDM sla and sls printers from my work. Are there any types of inserts that work well and hold up better? Which process is better for them? How do you set your hole sizes? I've seen some stuff online where people press them in with a soldering iron. Is that really effective?
Anything else I should know or can ready further about.
Thank you
 
Yeah those heat set inserts work great. They have different styles, unsure if they are for different securing styles. They are pretty strong if you use them responsibly.
 
FDM you can probably set inserts into most printed bosses with a soldering iron. Not sure how much smaller to size the boss.
SLS is probably a bit like FDM when it comes to melting plastic, so you should be able to set an insert into a boss with a soldering iron.
SLA sounds like that won't work. I think you'd have to make a boss where the insert fits, and then glue it in place according to https://formlabs.com/blog/adding-screw-threads-3d-printed-parts/
 
I have taken plain nuts and bolts and press fit them on a drill press with parts that have been .05-.1mm undersized. No heat.
 
Another tip: You may want to beef up just the area around an insert or screw/bolt attachment within your STL model, but keep the rest of your model as light as possible via reduced in-fill.

For example:

part.png


If using the Prusa Slicer, this can be done using a modifier. By right clicking on the STL model and then selecting "Add modifier", I can create a cylinder area to superimpose on each end of the part and then chose 100% in-fill for those selected modified regions. This way you can beef-up any region that has a insert/screw/bolt area where you would want 100% in-fill for it, but keep the rest of the model's part as light as possible using a reduced level of in-fill percentage.

Example:
1621371108606.png


1621370177024.png


Notice the STL is set to 25% in-fill overall, but the generic-cylinders I added as modifiers have 100% in-fill.
 
The inserts work really well. If you are looking for maximum strength, then like others have said, build in a nut on the back side of your print. What you use is really dependent on the design, size and whether it has to be really strong. At that point, you are not only taking your fasteners into consideration, but also your infill and 3D print material.

In my experience, ABS has been the strongest, but it also warps much easier. Nylon tends to be the toughest, but also flexes a lot.
 
Back
Top