.1 mm Layer Height Bridge Fail

[jckrieger]

Below are a couple pictures of my first .1 mm layer height print. I used the "standard" quality printing profile in Matter Control and simply changed the layer height to .1 mm. Is there a trick to getting bridging to work with this layer height? All the other settings were the same as the standard printing profile as defined by the assembly manual. This is black ABS, and I'm also using the standard ABS printing profile.

I'm guessing there's a setting to bridge with a larger layer height or to turn a layer fan on or something. Let me know what tricks I can try to resolve this issue. I also printed the calibration block that comes with Matter Control and it also had a problem printing the top of the block (same problem as seen on the top of the rook). I printed the calibration block 5 degrees hotter than the rook and both seemed to have exactly the same bridging issue.

If you guys don't have any recommendations, I think I'll try a little more in fill and try more layers for the "roof". I'm guessing with enough layers eventually the bridge would look ok.

[img]http://i202.photobucket.com/albums/aa44/jckrieger/20141212_083707_zps86e67bae.jpg[/img]

[img]http://i202.photobucket.com/albums/aa44/jckrieger/20141212_083857_zpsc21332d2.jpg[/img]

[Eaglezsoar]

A couple of things to try.
You could turn on the layer fan, try using support when you slice it, turn the heat down slightly.

[Polygonhell]

The issue with bridging at low layer heights has to do with how much the filament is stretched.
You can try a couple of things but the only one that will really fix it is a smaller nozzle. Things you can try increase the extrusion width, increase the flow rate while bridging, both are basically trying to require less stretching of the filament during the bridge. You can also try printing hotter, but this generally doesn't have much impact on ABS.

FWIW IME it's virtually impossible to get decent bridging performance at heights below about .15mm with a .5mm nozzle, and you need a nozzle closer to 0.35mm to get decent bridging at that layer height In fact with most 0.5 mm nozzles, at 0.1mm you can't even bridge a solid layer over 10% infill.

[jckrieger]

The issue with bridging at low layer heights has to do with how much the filament is stretched.
You can try a couple of things but the only one that will really fix it is a smaller nozzle. Things you can try increase the extrusion width, increase the flow rate while bridging, both are basically trying to require less stretching of the filament during the bridge. You can also try printing hotter, but this generally doesn't have much impact on ABS.

FWIW IME it's virtually impossible to get decent bridging performance at heights below about .15mm with a .5mm nozzle, and you need a nozzle closer to 0.35mm to get decent bridging at that layer height In fact with most 0.5 mm nozzles, at 0.1mm you can't even bridge a solid layer over 10% infill.

Now that's the type of information I'm looking for! I knew I'd reach the limit of the .5 mm nozzle at some point, and it looks like I've found the limit as you indicated. Bridging performance was very good at the stock .3 mm layer height. I think this is a good opportunity to pick up a smaller nozzle.

So far I'm quite impressed with the quality of the prints. The prints don't have anywhere near the surface finish of our pro SLA prints here at work. The next time I need to bridge a gap with this nozzle at a reduced layer height I'll make sure to do 100% infill.

[Glacian22]

I agree with the unbridgeability of thin layers, but you can counter this a little if whatever slicer you're using has a bridging specific flow modifier. IE crank up the flow 50% only for bridges, and definitely push the fan to max.

[jckrieger]

I've been messing with some bridging at .2 mm with my .5 mm nozzle and have been getting pretty decent results. I'm having some trouble with my hot end (can't get it to maintain above 233 C with a 238 C set point). I did crank up the flow modifier to 1.5 while bridging. Next I'll try some .15 mm layer prints to see if the higher temps and flow modifier made much of a difference.