Slicr 0.8.2 released 5/29

[mhackney]

Fixes a bug in the previous release.

Slicr is really getting sophisticated! The new Plater tab is very cool and I was literally just thinking "it would be great to start each layer at random locations or offset from the previous layer" because the wedding bands I printed have a seam that can pop open. Low and behold, Slicr now has a randomize starting point option!

cheers,
Michael

[JTCUSTOMS]

So whats the bridge flow ratio setting for?? in the advanced tab

[guanu]

Bridge flow ratio (default 1), is if you want more or less material extruded while traveling bridges...say on bridges your filament doesnt cross the bridge, but breaks mid air, you can increase flow rate for making across the bridge... on the other hand, if your bridges sag and too much material is being extruded you can dial it back to have less filament extruded crossing bridges.. (think of the number as a x100%... 1 = 100% normal extrusion, 0.9= 90%, 1.1 = 110%... etc)

Guanu

[johnoly99]

Yep, I usually dial mine back a tad, say .9 or so, and see what happens

[JTCUSTOMS]

What happened to the scale feature in 7.1?
I could import a drawing and scale it for 25.4 for standard units now I cant find it. I see the scale button in the plater tab but it will only scale what is already there not what is imported.
Overall though I am VERY pleased with the new features they are implementing good stuff

[michaellatif]

They fixed a problem with how objects are sliced, mainly with overhangs, my prints are more true to the design. I went back and reprinted the iPhone case and its MUCH better. Almost makes me want to go back and reprint some other parts that didn't quite slice right.

@JTCUSTOMS - I don't know where the scale feature went, it was useful, I found I used it quite a bit. It might have been buried somewhere. I will see if I can find it and let you know.

[JTCUSTOMS]

Thanks Mike, I looked till I was crosseyed!
I still cant get bridging good enough to pull off that case yet but hopefully I am narrowing in, what is your bridging speed set to? bridging ext. ratio?

[Polygonhell]

Bridging is mostly about temperature and ensuring that you're extruding enough that you are stretching the filament slightly.
In slic3r the only setting that really matters is temperature.
You can bridge at almost any speed from 10mm/s to 60mm/s with similar results.

[michaellatif]

I disagree with you Polygonhell, bridging is about extrusion rate of filament across the void. If the extruder is pushing out too much filament then it will sag, if it is too little it will snap or not print a proper layer for further layers. If the temperature is too hot, printing any layers will be difficult, that's why I run my ABS around 210C-212C.

I am currently playing with .85 and .90 bridge flow rate at bridge feed rate of 20mm/sec. It still gives me a minor sag, but I think if I dial down the flow rate it will eliminate it.

[JTCUSTOMS]

I am probably printing too hot, I am running 3mm abs now, @ 250-255C
LOTS of sag, will try dropping the temps a bit to see how much it helps

[michaellatif]

Holy crap! 255C??? How do you keep from chocking and dying from the fumes?
I have found that the lower the temperature the better print quality will be, I tried playing with 190C - 200C, but was too low, 205C is what I find absolute minimum for ABS on my rig.

What I don't know is what does the filament size do to the melting temperature? Is that why you run much higher? I only have been using 1.75mm filament, so maybe that's why I can run the lower temps?

[mhackney]

In theory, the same ABS in 1.75 and 3mm would have the same melting temperature. However, since the filament has to be melted quickly as it passes through the extruder, more heat might be required to insure the 3mm melts properly. Just a guess! But 255C is very hot and I agree, I get fumes and smoke at that temp.

cheers,
Michael

[Polygonhell]

I disagree with you Polygonhell, bridging is about extrusion rate of filament across the void. If the extruder is pushing out too much filament then it will sag, if it is too little it will snap or not print a proper layer for further layers. If the temperature is too hot, printing any layers will be difficult, that's why I run my ABS around 210C-212C.

I am currently playing with .85 and .90 bridge flow rate at bridge feed rate of 20mm/sec. It still gives me a minor sag, but I think if I dial down the flow rate it will eliminate it.

I agree to some extent, but because of the way slicer calculates the w/h ratio (even if you try and set it explicitly) and the fact it derives the extrusion width from that, there is a danger that by reducing the flow for bridges you don't get complete coverage of the bridge.
In general the settings people use for Skeinforge result is significantly less extrusion and a much narrower extrusion width than you see in Slic3r, with a reasonable >1.5 w/h that will result in better bridges.
I actually don't think Slic3r is doing what the author intended, there is code in there that limits the extrusion width to between 1.01 and 1.4 x the nozzle diameter, in most normal situations, the computed values get clamped rather than using the computed value.
The clamping is still applied when w/h is set explicitly, so you don't get what you ask for.

[JTCUSTOMS]

Holy crap! 255C??? How do you keep from chocking and dying from the fumes?
I have found that the lower the temperature the better print quality will be, I tried playing with 190C - 200C, but was too low, 205C is what I find absolute minimum for ABS on my rig.

What I don't know is what does the filament size do to the melting temperature? Is that why you run much higher? I only have been using 1.75mm filament, so maybe that's why I can run the lower temps?

Yes, I know its a little hot, but I am getting very nice prints at that temp.
I am trying another print right now in the 220-230 range using 3mm black.
My printer is out in the shop which is about 50yds away from the house so I cant smell it from here haha!!
I will continually drop temp and see what works best. I ran 1.75 filament at the same temp.
One thing I did notice is that the fill looks alot tighter at 220.
BTW I printed at least 20-30 things including 4-5 hr prints at the higher temps. Even yoda turned out ok.