jfjohnny5
Posts: 14
Joined: Wed Apr 10, 2013 9:18 pm

Tips for Improving Bridging?

Sun Apr 14, 2013 4:25 pm

I've been calibrating and dialing in my new M2 for the last week or so when I have time to work with it. I'm currently getting some really nice prints - loving Creator. Bridging is the next area I'd like to focus on. I've been using both the 5 mm Calibration Steps http://www.thingiverse.com/thing:24238 and the Ultimate Calibration Test http://www.thingiverse.com/thing:9804. And to be fair they both look quite good.

With the 5 and 10 mm overhang sections of the 5 mm Steps I get small loops that drop down with the bridged infill.

With the Ultimate Test I get some sagging starting at around 15 mm.

Images:
http://www.flickr.com/photos/7943855@N05/8650003542/
http://www.flickr.com/photos/7943855@N05/8648857041/

Again, I do think they both look quite good - but I'd like suggestions on what settings I might try adjusting to really kick it up to the next level.

Simplify3D
Site Admin
Posts: 304
Joined: Sun Feb 10, 2013 8:28 pm

Re: Tips for Improving Bridging?

Mon Apr 15, 2013 6:46 am

Hey Johnny,

Glad you're enjoying Creator thus far! We also battle with bridging a lot here in the lab, so let me make a few suggestions based on what I've learned from lots and lots of testing. First, ABS usually does better bridging than PLA. In general, PLA is pretty stringy and doesn't pose a lot of resistance against droop for long bridging segments. I'm not too surprised you're running into it around 15mm. Creator has some pretty smart algorithms included to identify and optimize infill printing. Most of this happens behind the scenes, but if you look at the "Other" tab under the Bridging section, you will see the settings that the user can play with. You can choose the ideal extrusion multiplier (flowrate) and speed multiplier to use when printing these sections. You usually want to try to slightly stretch the filament as you extrude across a bridging region to make it a little tighter and less prone to drooping. You might want to try dropping the extrusion multiplier by 5% and see if that helps. You can only reduce this setting so much before the filament breaks or the fan is too strong for it and actually blows it out of place. I might also try printing these segments at both higher and lower speeds. We see mixed results with this one, so you might need to experiment on the actual part to see what works best. Finally, lower temperatures always produce better bridging. If you can drop the extruder temperature by 5 degrees, it will help the bridging segments cool faster and not droop so much.

Hope that helps!

jfjohnny5
Posts: 14
Joined: Wed Apr 10, 2013 9:18 pm

Re: Tips for Improving Bridging?

Tue Apr 16, 2013 9:54 am

Thanks for the tips! It helped quite a bit. I ended up cooling the extrusion temp by 10 C. I also reduced the bridging extrusion multiplier by 5%. Finally I set the speed multiplier to 150%. I was able to bridge a 50mm gap with a droop of only about 0.5 mm. That's pretty good if you ask me!

JamieLaing
Posts: 6
Joined: Fri Sep 19, 2014 7:15 pm

Re: Tips for Improving Bridging?

Fri Sep 19, 2014 7:21 pm

Hi guys,

Simplify3D has changed my life, dramatically improving my prints and generally restoring my faith in humanity. I don't need to tell you the name of the company that crushed that faith. But anyway Makerware has this bridging feature that I would perhaps describe as either "over extrusion" or "bridging specific toolpath overlap". Whatever it is best called, the result of this bridging technique is that the bridge material ends up being expressed as a solid sheet instead of an array of closely spaced but non-fused strands.

Any chance there is a tweak to achieve the same result in S3D?

Bobo
Posts: 3
Joined: Thu Dec 25, 2014 1:05 pm

Re: Tips for Improving Bridging?

Tue Dec 30, 2014 3:27 pm

For me Bridging seems to be the last problematic area. I can't seem to figure out how to eliminate surface scraping and grinding sound with the bridges. I have reduced the Bridging Extrusion Multiplier to 90% and have slowed down the speed multiplier to 60% to no avail. It still produces grinding and Scraping.
Thank you!
Bob

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