Trefoil Knot - Version 04 - Large Segmented

I wanted to scale up my  trefoil knot  print, so I designed a version which can be printed in “fit-together” segments.

Print Instructions

The knot is printed in six segments with “socketed” connections. In order to keep track of the individual pieces, I gave each segment a distinct color in CAD, and then labeled the STL files accordingly :

1. Blue
2. Brown
3. Gold
4. Gray
5. Green
6. Purple

Note that I used the colors strictly for identification; I printed all parts in yellow PLA. The parts are designed to be scaled up by 200%; greater or smaller scaling may be possible but I have not tested other sizes.

• scaled 200%
• compensate for elephant's foot

I printed each segment one at a time, and to simplify assembling the segments I labeled each segment with it's “color," using a felt tip pen on the inside of the tube.

Each segment forms an “arch” on the printing plate, and my prints showed a bit of roughness on the underside of the arch. This could likely be alleviated with supports, but I did not want to spend the extra time or material to experiment with this possibility. Another possibility would be to print each arch “upside down” with minimal supports on the bottom - possibly a future experiment.

On some of the segments there is some internal stringing where the “socket” transitions; these are easily removed with a razor knife. In addition, if the parts of the segments that contact the printing plate do not fit together easily, there may be elephant's foot “flashing” which can also be removed with a razor knife.

When properly “trimmed”, the segments should fit together smoothly and firmly without gluing (although of course gluing will give a more permanent construction).

CAD

The OnShape 3D CAD files are here :

https://cad.onshape.com/documents/f36468084e28f8df8fa36937/w/4ddd1ec94fcc3fbe8bf684cd/e/e203757048166706b080d91a