Unresolved A few quick questions

Hey guys I have a small handful of questions. First off I know that bridging is hard but whenever I i print the slightest overhang it droops and if i try to print even a small bridge it dosent work at all. Secondly every time the printer moves up a layer it leaves a little bubble. I included some pictures showing what I mean

 

Mark is correct. We need some more detail.

What filament?
What slicer?
What temp?
What speed?
What layer height?
Have you calibrated your extrusion?
Single or dual part cooling fans?

These all have a part in print quality when it comes to bridges and overhangs. It's mostly just a job of dialing things in.

 

With my personal experience, definitely turn off the bed heat if using PLA layers before the bridge to allow it too completely cool down. Dual Cooling fans are almost a must to achieve good results. From my understanding, you actually want to "stretch" the filament across the bridge, which lead me to keeping the same extrusion rate but increasing the Bridging Speed Multiplier (settings in S3D). Not sure which slicer you are using. But you will want to view the layers before printing so you can see what it's going to do at the bridge. I believe some slicers only like to bridge one direction, so you may need to rotate your model to make it easier. Make sure you have an extra inflation distance specified, so it travels past the actual bridge and onto a previous layer to help.

 

Im using Im using
Hatchbox PLA
Mattercontrol
between 190 and 200 for the extruder and 50 for the bed
I have similar results between .3mm and .1mm
What exactly do you mean calibrated my extrusion?
Single, my 3d printer is stock

 

This might be one of the most linked to videos on this forum. Here is how you can calibrate the extruder so you aren't over or under extruding.

 

I'd recommend adding a second 12v 40x40x10 part cooling fan. Here is a good mount for that.

http://www.thingiverse.com/thing:720018

 

Dual Fans is an excellent and easy upgrade, and like I said previously almost a must for Bridging. This is the setup I used: http://www.thingiverse.com/thing:1037680

There are also shrouds that just snap into place with no tear down required.

LOL Tom's video is all over this Forum! Someone should create a sticky instead, to include but definitely not limited to:

Extruder Calibration Steps (Tom's video)
Firmware Changes (actual bed size, max bed temp, Acceleration Settings, XY Jerk, etc)
Process of Elimination for Stepper Motor/Driver Issues (Swap Motors, Swap Drivers, Calibrate Drivers)
Common Issues to check first (different slicer, screws, belts, hubs, bearings, wires, etc)
Wiring Diagrams/Pictures for all Connections (Ramps, Endstops, Connectors at the X-Carriage)

Might be too much for one sticky! Then we can just send everyone to that Thread and all the information is there? Thinking out loud again!

 

I hear there is a FAQ in the works.

 

I have done that already btw

 

apperently its extruding while moving over gaps? take a look

 

So that is a lot of stringing. Did you use any supports to bridge with? Looks like it needs it.

 

Also - I would tweak temp first and then retraction. For temp, play around a little, but you basically want the temp as low as you can get and still get proper extrusion. For some of my filaments that's 188 or so. I almost never print above 195 using my current filament. Again - those numbers are printer and filament specific, but the point is to make sure you are not printing too hot. Then, once at the proper temp, you adjust the retraction to take care of the rest of the stringing.

 

actually you might have a little more luck with that model flipping it over. The curve looks like it might be enough not to need supports if you print it in that orientation. I think that is most of the issue because bridging on a curve...well that just doesn't work very well as you found out. A straight line, yeah with the correct temp like Toro mentioned, dual cooling fans, and a couple other tweaks it bridges like a boss.