PETG 92 mm Long Bridge in Mean Well Power Supply Cover  

RE: PETG 92 mm Long Bridge in Mean Well Power Supply Cover

Posted by: guy.k2

This is the 3rd time I've printed this and it makes me smile seeing it complete the bridge in this piece. Printed at 0.15 mm layer height in Amazon PETG, only 5 strands are loose. There is a slight bow to the bottom of the bridge, but the Prusa successfully bridges PETG across a 92 mm gap without supports.

The model is http://www.thingiverse.com/thing:3111868

Only have to cut off the five loose strands and the piece is ready to use.

The first time I printed this, I did not notice the long bridge in the model during slicing. Otherwise, I would have specified a support. Came back and was astonished to find a completed piece with a ridiculously long bridge.

After that first time, I know the Prusa is up to the job.

Nice to see that. I tested long bridge too but I got a big bow that impacted the upper and then top layers. Then I redesigned my part to decrease the bridge.

But as you say you got good result with 0.15mm height, that makes me thinking that my bridge layer was too high. My layer height was 0.3.

I had a mass per unit length that is double than yours. The tension on the filament is may be the same in the two cases (may be not). According to https://en.wikipedia.org/wiki/Catenary#Mathematical_description, the curve of the bridge is quite different.

I will test when doing long bridges smaller layer height.