Elephant foot

[kam]

I am having a bit of trouble figuring out how to reduce / eliminate the first layer getting squished more than the next (i think that this is called elephant foot). First layer are just a bit wider than the rest and normally I just to sand it or cut i away, but is there setting that can help me eliminate this while still getting first layer to stick?

I think a read this mentioned when reading about new stuff in version 4, but I havn't been able to find this since so maybe it's my mind playing a trick on me...

/Kasper

[jfkansas]

Is it worth messing with and losing print quality because of warping or things lifting off the bed? You could probably add a small radius to the bottom of the design, but that isn't related to S3d. I would just scrape it off and worry about other things. It can't take more than a minute to touch that up with a hobby knife, a little sanding, or using a deburring tool.

[zemlin]

Under the GCODE tab you can add a Z offset which will impact the first layer. Positive will decrease the squishage on the first layer. Negative will decrease it. At least that's how it works on my printer.

[dkightley]

The art of 3D printing is to understand what the process is and how changing printer and slicer settings affect how the end product comes out....and there are no settings that are specifically designed to cure issues with the printed product. There are no "magic" settings!!

You have described a symptom referred to as "elephants foot"....which is simply the first layer of the print being laid down with the nozzle too close to the bed for the amount of plastic being extruded. This results in a wider bead of plastic that the slicer has expected to be extruded. Now, you are likely to have set the nozzle closer than expected to the bed in an effort to prevent the first layer from lifting off the bed under the stress of the previously laid plastic cooling and wanting to shrink.

As suggested by the previous poster, you may have cured one problem (the lifting) either by lowering the nozzle (by global z adjustment) or by reducing the first layer thickness down (to a value somewhat lower than 100%). This has introduced another problem ( the elephants foot), so you may now wish to consider other measures to prevent lifting that don't give this issue.

Not knowing what material you use, I can suggest perhaps a slightly higher temperature and slower printing speed for the first layer for PLA, or using a higher bed temperature or enclosing the printer so it doesn't cool as rapidly for ABS. These changes make a difference to the physics of the printing process.....and understanding what happens will make it easier for you to diagnose and correct issues that may turn up when printing. Other measures to prevent lifting include using a skirt and strategically placed "mouse ears"....small circular one or two layer thick sacrificial pieces that are connected to the part in areas that tend to easily lift. These are removed after printing.

The bottom line is.......get to understand what the settings do, and the effect on the printed model. S3D is a great tool for printing almost every size and shape of part out of a range of materials with differing properties. To get the best out of your tools, you need to learn and understand how to use them.

[pabalo]

I would love an "elephant foot compensation" setting just like in Slic3r, which simply shrinks the geometry of the first layer by that amount then gets processed to be normally filled through g code. Then the next slices come and squish the geometry correctly. 0.5mm works awesome for me (Print Settings > Advanced > Elephant foot compensation).

AFAIK, in S3D the settings "first layer height" and "first layer width" actually extrude a proportional amount of volume of filament according to the volume of that new first layer (since it can be taller/shorter), so it just disperses the same (proportional to height) amount of material in the same space. I have tested these settings a lot, and I concluded that it can't help with elephant foot problems, hence why I sometimes use Slic3r in first layer critical jobs.

Yes, I know I can spend 5 minutes sanding/deburring every print that could have been easily tuned in the slicer. And I know I could also spend 5 minutes designing my stl to have a step of specifically the slice's layer height and the elephant foot compensation. Call me lazy, but Slic3r has just the right solution for this problem.

Again, I would love to see this setting on S3D and not need to go to Slic3r just for this.

[tonyno]

You can do this with Horizontal Size Compensation for the first layer (separate process).

[airscapes]

You don't have your starting height adjusted correctly.. With the staring height correct you have adhesion and no elephant foot..
Follow your machines manufactures instructions for leveling the bed and setting starting height.

Best tool do to this is a single wall square with a width of your extrusion and a height of 2 mm. Print with a .2 mm layer height and measure it with a digital micrometer. It should measure with in .02mm of you the size it is.. adjust extrusion multiplier to get wall thickness correct and starting height to adjust height. You must enable single wall extrusion in S3D for this to print

I have attached several files of different extrusion widths

26x26x.4x2.stl

(1.64 KiB) Downloaded 733 times

40x40x2x.3.stl

(1.64 KiB) Downloaded 658 times

40x40x2x.5.stl

(1.64 KiB) Downloaded 634 times

[dkightley]

You don't have your starting height adjusted correctly.. With the staring height correct you have adhesion and no elephant foot..
Follow your machines manufactures instructions for leveling the bed and setting starting height.

To complete the steps required.....


After setting the bed level as above, print a test piece and look at the finish on the bottom.

If you can see a non-smooth finish then you have the extruder slightly too high. If the finish is smooth and there's an "elephant's foot" then the extruder is too close. The optimum finish is a smooth surface with no "elephant's foot". To fine tune the extruder height, use the Global-Z sett on the GCode tab of the settings.

To lower the extruder, adjust the Global-Z value in the negative direction. The value can go negative. To raise the extruder, adjust the value in a positive direction. Start by adjusting say 0.2mm and reprint the test piece and see what has happened. Repeat until you're happy with the results.

You now have the bed level and the extruder height fine tuned......and you should be able to get good prints.