Bridging - Help Please!

Here is my setup:

Mendel with Ramps 1.2, running sprinter, pronterface and slic3r, hot end from mixshop with a 0.5mm nozzle.

I've been test printing with 3mm natural PLA on blue tape, following the steps at [reprap.org] .

I'm printing 0.3 layer thickness, everything is just excellent, until bridging.

o Idea how to get that shape to print successfully. With my layer settings, the top face has three layers... my gcode is here:
[ffaat.pointclark.net]

The first layer of the bridge does not seem to adhere at all to the perimeter. and made a big glob of filament, the second half spanned but sagged, and the top layer spanned, but all loosey-goosey, probably because there was no support below as the first bridge layer crapped out:


I also have an 80mm fan blowing on the print area from around 1 foot away.

Any suggestions whereto start, as I can't locate an equivalent to the BRIDGE FEEDRATE MULTIPLIER parameter...

-Rob A>

Going from empty air to a nice surface layer is a very demanding test, especially when the bridging only has the perimeter to attach to. A good setup can go from 0.15 or denser infill to a perfect surface in just three solid layers, but from thin air? It can take three layers to just to get a stable enough base to put the further, clean layers on. In fact, if the picture shows your third layer on top of nothing, I'd call that a very nice result already. Just use a few more solid layers when you actually need to print an object like that.

HI Rob,

Welcome to reprap.

Your prints look fantastic. I looked at your G code, and if you have not already solved it by now I could only suggest changing 2 things to test.

-------snip your code------
; filament_diameter = 2.84
; extrusion_multiplier = 1
; perimeter_speed = 55
; infill_speed = 80
; travel_speed = 130
---------------------------------

Can you confirm your Filament is 2.84? that seems a tad undersized.
Would you be willing to try a slower speed on the Infill?

I know for my my Prusa, I slowed everything down (Perimeter, Infill, and Bridging) to the 20's and 30's to start, and increase from there.

I also found that A very high travel speed would sometimes throw off either and X or Y randomly so that also gets kicked back down on my printer.

I like the print you posted, great job on your first prints. I wish mine looked that good the first time.


Regards