Bridge anchoring - How does Prusa get large anchors?  

RE:

Depends what version they used.  Bridging has changed (and gotten some issues) in the recent versions.  You just have to look at the issues on the github to see that.

The gcode should have what version it was sliced with and even the general settings embedded within it.

RE: Bridge anchoring - How does Prusa get large anchors?

Posted by: @robin_13

I am trying to print my MMU3 parts but I don't want to use the Prusa gcode as I need to keep my print times under X hours so after getting my printer and filament calibrated, I have started the print.  Now I have an issue with bridging on two parts for the second layer.  Every time I try it fails on the second layer bridge.  It has taken me quite some time to get bridging working on my printer and PETG.  As this is the second layer, the fan setting I have for bridging don't work.  The bridges are just lumps of filament,

I looked at the Prusa gcode for the same part and find that their bridges have large anchors.  I have looked through the forum and see that there are questions about the bridge anchor but no answers.  I want to know how Prusa did it in their gcode.  In the attached image, the part on the left is my sliced copy, the one on the right is what is in the Prusa gcode. 

Am I to assume that Prusa doesn't even use their own slicer?

There's a file on printables that fixes this issue. Just search mmu3 on printables

RE: Bridge anchoring - How does Prusa get large anchors?

@robin_13

The last good bridge control was in version 2.4.2, things went down hill after that. I would recommend using it still if your printer will allow it. That said there are things you can do, workarounds and such in the later versions, but its a fight.

RE: Bridge anchoring - How does Prusa get large anchors?

For the image, I downloaded the Prusa file from printables but it is two parts and a 17:40 print.  It is also not tuned for my printer such as filament flow which I had to increase by 5%.  If I could cut out part of the provided gcode and only print one part at a time would be great.

What I may do is cut out the two layers from the Prusa code and overlay it into my slice for that part. 

Or try a different slicer.

RE: Bridge anchoring - How does Prusa get large anchors?

I will look at the github site and see if I can get an older version of the slicer.  I have a MK3s+. 

RE: Bridge anchoring - How does Prusa get large anchors?

Found the 2.4.2 and the bridging is the same as what shows up in the Prusa gcode file.  I want to do some test prints as I may have to modify my bridging settings for this but it may be the solution.  Will test between the two different slicers.

RE: Bridge anchoring - How does Prusa get large anchors?

Okay, spent the rest of the afternoon playing with this.  Turned out that my settings for bridging feed was causing the issue.  At the height (0.2mm) with no fan, the filament was curling up and creating lumps that caused a crash.  From the tests I did, I only needed to change my setting by 0.08 more.  Will try to slice and print the parts tomorrow, time permitting.  So much more to learn about 3D printing.

In my searches, I did find other cases where people were asking the same question about the bridge anchors and how to adjust them.  I did find that 2.4.2 does do large bridge anchors so Prusa must still be using an old slicer.