first overhang / bridge attempt

Hello!
so i tried my first overhang + bridge yesterday.
the bridge was ok, although the material was a little difficult to remove (as it was in a very thin gap)
the overhang however didn'tr eally turn out that great... (image attached)

it was done at a 0.1mm layer height.
It almost looked as thought it failed to bridge a very small gap, not too sure though
The print seemed to recover once it reached the top layer of the overhang, just the lower layers were messed up

I'm going to have another go tonight/tomorrow. any tips on what to change in the slic3r settings??

any input always appreciated

Try slowing down the speed of bridges and gap fills (under the "speed" settings of Slic3r). Try 10mm/s or even lower. Reducing extruder temperature might also help - the idea is to try to cut down the length of molten plastic that is trailing behind the nozzle. Another thing you can try is blowing an external fan on the nozzle when it gets to the bridges (perhaps use a small battery operated fan or a hose from a vacuum cleaner - which will cool whether you use the "blow" or "suck" end). Sometimes the extruded plastic can detach and curl up, which has a risk of catching the nozzle later and making the X or Y stepper miss a step, or knocking the print off the base. I always watch for that situation when the print reaches a bridging section, and am ready with a needle file to try to push down or file off any curls quickly while the print head is out of the way (if there's time!).

The print you are attempting has a curved section that is printed in the air rather than a simple straight bridge, which may well need support to print successfully with no external cooling fan. Cura does a better job of adding support than Slic3r (If you go that route you will need to download the plugin for Cura - see the "Cura" topic on this forum). It is also close to the bed, so you could try reducing the bed temperature so the bridge cools faster.

Dave
(#106)

apologies i should have been clearer.. the labeled overhang did have a support underneath. it that has been removed in the image.
The underside off the support for the overhang actually looked quite well formed (cun upload a pic later) but the touching face of the model looks really deformed.

Yes i had to use a small tool to flatten two sides of a curling where deformation has occured. still came out looking really awful


im going to look into cura.

The external fan & slower speeds sounds like good ideas, that will be the next test.

lowering the bed temp soudns good too! im assuming i should do this after the first couple of layers.

thanks again dmould

Edited 1 time(s). Last edit at 03/13/2014 10:50AM by 88Zombies.