Best Material for Linear Motion System Brackets

Welcome to the community.

As with anything related to 3D printing, material is only have the battle. Design has more influence on strength, durability and survivability.

  1. Do you have a concept of what the device will look like that you can share? Size? Weight?
  2. What are the environmental conditions that it will have to survive? Can we assume indoors? Are there temperature extremes such as contact with a hot motor?

Once the parts are extruded, moisture absorption is not an issue. However, you didn’t state how you’re mounting the pieces. Were you relying on self tapping screws? Are you embedding nuts or thread inserts into the material? Or are you tapping threads into the material? Or are you using simple through-hole nuts and bolts?

If you’re looking for precision, you’ll want to use as much metal as possible. Also, whatever filament you chose, you’ll want to use solid walls and not rely on infill. I posted an example of that the other day which will show how to get strength out of infinite walls and zero infill.

For my material, my preference is PC because of its rigidity when printed at 100% wall thickness, but one could achieve similar results with any of the filaments you mentioned. I happened to have a fondness for PC because it produces ABS like results without the fumes, albeit, it will never win any beauty contests because there will usually be some zits, loops and other items that may need to be cut off. It is also a more of a functional filament because it’s never fully opaque and therefore the limited colors it comes in give almost a hard candy appearance due to translucent properties of the filament, but the results as far as strength and regidity speak for themselves.

Also, don’t forget that layer orientation will have more influence over flex and strength than anything you can possibly design.