Feature request: top solid surface layer feed/flow modifiers

Dunno if Enrique follows this group but I've got a suggestion...

I'm printing a lot faster lately - finally getting the hang of the ultimaker - and find that my top-layer surface quality suffers when I really turn up the feed rate.

Infill in the interior of the object isn't blobby or anything, it's just not as smooth as I'd like. What'd be really nice is if there were feed/flow modifiers for the outside/top solid surface layer, similar to the existing perimeter feed/flow modifiers. That'd let me shovel plastic into the middle of the object then do slower, smoother threads around the perimeter and top..

Thanks!

It's a good idea, but you might also need a small retraction of the filament at the beginning of the slow section, and a small advance at the end of the slow section, to combat the change in filament hysteresis.

raldrich Wrote:
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> It's a good idea, but you might also need a small
> retraction of the filament at the beginning of the
> slow section, and a small advance at the end of
> the slow section, to combat the change in filament
> hysteresis.

Technically yes, but it would be a very small single defect at the start of the slower section. No worse than switching from fast infill to slow perimeter.


I

If you download the development version with the Skin plug-in, that has a separate feed and flow rate which affects the top surface.

JB

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...the Skin plug-in...

Oooo.. Thanks!

It'll be interesting to see how that comes out. The docs make it sound like it's all about printing perimeters at 1/2 the layer height (doubling outside apparent Z resolution) but the params on the plug-in itself make it look like a top/bottom surface thing.

I think I've almost got my volumetric 5D e_steps setting right.. Once I get that done (and can move past skeinforge 39), this new plug-in is on the top of my list of stuff to poke at.

I need to update the comments in the skin.py file they are a little out of date. Enrique added the top surface skin modifier for me as I couldn't figure that out, but I haven't gone back to update the comments yet (too many other projects on the go at the moment)

JB

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jim_blag
..the Skin plug-in..

I tested this out tonight with layer thickness = 0.15, perimeter & infill w/t = 2.66 (for .4mm thread width), solidity = 1.0, feed rate = 133, perimeter feed & flow ratios = .33 and skin top multipliers = 0.5. Just a couple copies of the good ol' 20mm calibration cube.

Vertical surfaces are just frickin' AWESOME at 0.075mm.. I can barely feel the layers with my fingertip..

I'm not sure I agree with the way the horizontal surfaces are done, though.. It looked like those are also done at 1/2 layer height, which I don't think buys you much in terms of resolution. Dropping the feed/flow down to 1/2 speed is great - just what I was looking for - but also doing them at 1/2 layer height may not be the best way.

I think what'd really get the best quality would be the keep the 1/2 height perimeters then have separate feed, flow and w/t multipliers for solid surfaces. Layer thickness doesn't matter as much on the horizontal - thread width (via w/t) is really the key on that.

Tiny thread widths always look best but they're not very sound, structurally. If you could get them just on visible surfaces, you'd be able to keep the object strong and get better resolution..

Glad you like the effect.

It's printing the horizontal surface at half-height so that it can print the top surfaces with half-width threads, so you get a similar effect on the horizontal surfaces as on the vertical surfaces.

JB

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Check out my blog: AdventuresIn3-DPrinting

Ok. Thanks.. I didn't notice that they were at 1/2 width too..

Still, if I had a vote, I'd vote for infill to be done at full height and 1/2 width or at a specified width - I've always found it difficult to get a nice fill at both thin vertical and thin horizontal.

Dave Durant Wrote:
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> Ok. Thanks.. I didn't notice that they were at 1/2
> width too..
>
> Still, if I had a vote, I'd vote for infill to be
> done at full height and 1/2 width or at a
> specified width - I've always found it difficult
> to get a nice fill at both thin vertical and thin
> horizontal.

If you mean a W/T ratio of 0.5, then I don't think this is possible. You can only compress the filament downwards, not sideways, with the extruder tip. So, W/T has to be 1 or larger. Maybe I misunderstood you.

I was using layer height =0.15 and w/t = 2.66 so, if I understand jim correctly, it was printing surface layers at 0.075 with 2.66w/t.

What I'd like is to be able to specify w/t and feed rate for the surface layers. That or have it not cut surface layer thickness in half - a 0.15mm layer height with 1.33w/t would be better (IMO) than 0.075 with 2.66.

I think you've got the wrong end of the stick. It's divided everything by 2. So the thickness is half-height and the thickness is half-thickness. It now requires 4 threads in place of the one it replaced. It's the equivalent of printing the last layer at half carve height - but it prints two layers to keep the original dimensions correct.

The diagrams here show what is happening on the perimeter, but the same applies for the top surface: Skinning Diagram

JB

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Check out my blog: AdventuresIn3-DPrinting

Ok, 0.075 layer height and 1.33 w/t on the solid surfaces..

This is a great idea on sane resolutions but makes doing really high resolution tricky - fill that that's thin in both horizontal and vertical an be hard to get right.

It is a massive improvement, though, and I don't often take the time to do really high-res stuff..

Thanks!

The way Skeinforge plug-ins adjust the GCode is sequential. So the top layer is already sliced before Skin gets hold of it. It would need to re-slice and recalculate the paths if the everything else needs to change. Not impossible, but way outside of my knowledge of the inner workings of Skeinforge.

JB

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Check out my blog: AdventuresIn3-DPrinting

I have actually changed the skin plugin in SFACT a slight bit as it only prints 2 extra extrusions instead of 4. just makes them wider to fill the space...
Results:
First 15 layers 0.4mm last part skinned.. (0.2mm)
[www.flickr.com]

This Yoda: 31mm high only. printed in 0.2mm with skin>>0.1mm
Note that the picture is extreme Macro.. for reference: the red cap is WD40, and the PLA printed piece is the middle piece from the perimeter width test..
[www.flickr.com]

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Manufacturer of low tolerance Filaments PLA, ABS, ASA, PETG, TPU, PA, PVA,
[www.miafilament.com]
[github.com]