Odd Warping  

RE: Odd Warping

You are printing some steep overhangs; this design comes up against the limitations of FDM printing when building things layer by layer.

I'm guessing the affected part was towards the rear of the printer and not getting cooled as effectively by the print fan. Cooling is critical for overhangs, and non-uniform cooling is a common gotcha in many printer designs.

The easiest way to avoid this is to  change the part orientation. For example, split it in half along the edge of the blade and glue the two halves together later, or split it  so it prints in two pieces with the long dimension vertically, to turn the overhangs into supported top surfaces.

There are other things you can do like a smaller layer height but that looks to be above 70 degrees, so layer height may not help much. 

RE: Odd Warping

Alright, thanks so much for the response! I'll give splitting it a try, and see how that goes.

RE: Odd Warping

In addition to splitting the part, you may want to increase bed temp from 60c to 70c when printing longer items like this; even PLA tends to warp and pull up from the bed.  You can also turn the part so the pointy end is forward, this maximizes air flow to for bridging on both edges of the blade.

For best print quality - I'd cut the blade in half at the thickest section, and place the cut face on the bed, edge up.  This builds to the finest resolution the printer can do.  

RE: Odd Warping

While it may sound counterintuitive, I'd print it standing, sharp tip up. The benefit would be a more conforming layer orientation, making for a much nicer surface finish and no warping to battle. The drawback would be a ~50% weaker part, easier to snap. And the need of supports to avoid toppling. To force supports around the part, I would place a flat disc created in Slic3r above the part, such that Slicr3t supports the disc and builds a scaffold around the blade.

RE: Odd Warping

Printing with the blade vertically will result in a weak part (less flex but will break much sooner), invite all sorts of adhesion and initial layer issues with the tangs, and part flex and shimmy as the extruder builds vertically will destroy part quality unless significant model changes are made to adapt to vertical printing.  Though, if you do decide to try printing vertically, use the smallest layer height you can as that will help strength. 

One advantage to printing vertically is increased detail in the blade cross section; and elimination of the "layered" look. If you overcome the wobble problem by redesign, the part could look more realistic. But by cutting down the middle as I suggested, layering artifacts are reduced as well.

RE: Odd Warping

Thanks for the responses everyone! I tried splitting it, and included some holes/inserts in the two pieces so that I wouldn't need to glue as much. It turned out pretty well, I just made sure that the end with the blade edge was facing the fan (I also used a slightly different blade design). I'm still messing around with some other options though, I would really like to be able to print it all in one piece, though that might not be possible.

RE: Odd Warping

I think you aren't quite getting the method being recommended.  Sharp edge up. middle of blade on bed.

Here's an example with a sword from Thingiverse ...

You can add a couple of 1.80 mm holes in the parts for alignment, and use raw filament as pins.

RE: Odd Warping

Played around a bit more ... tree supports with the part vertical (tangs would have to be added as inserts).  Eliminates gluing, but a few trim marks from the tree.  A bit of design effort would minimize the tree contact to 0.4 mm.  Also reduces strength to inter layer adhesion.

RE: Odd Warping

Thanks for the continued advice, I'll have to give that method a try! I did manage to get a fairly decent one piece print, by printing the blade with the edge facing down. I actually ended up switching to Cura for this (I have more experience there) since I couldn't get the supports to do exactly what I wanted in Slic3r PE.