Pleasant3D is now open source

I hadn’t too much time for developing Pleasant3D lately. Sorry for that!

However, I did some work on Pleasant3D in the last year:

  • Better (more performant) versions of the Quicklook  plugins (for previewing STL and GCode files in the Finder)
  • An experimental implementation of a DAE file import plug-in
  • Experimental support for printing directly from Pleasant3D (still not functional, but the infrastructure is there…)
  • Support for different devices (3D printers, CNC mills etc.)

… and some other stuff.

Unfortunately, I currently don’t have the time to develop, test and stabilize the current code on my own in order to release a new binary version of Pleasant3D.

So starting today, I open source the complete code base of Pleasant3D:

https://github.com/zaggo/Pleasant3D

(The slicer plugins of Pleasant3D were open source from the beginning. I’ll mark the old open source BitBucket repository as obsolete.)

I’d be very happy, if some of you 3D-printing (or CNC-milling) Mac developers out there would help with the further development of Pleasant3D!

Please note, that the published sources aren’t in a fully tested state. As far as I can tell, the project builds and runs after a clean ‘clone’. Be sure to use Xcode 4 and to choose “Pleasant3D/32-bit” as build scheme.
However, there seem to be some issues with the Quicklook generators in this version (they seem to run in Debug mode, but crash when running in the real world…).
Also the OpenCL slicer seems to be broken in the current version.

The  stable version of Pleasant3D (v2.0) is (and will be) still available as pre-built binary release: Download Pleasant3D

Flat Teardrop

The teardrop is around in the 3D printing scene virtually forever. It’s even part of RepRap’s icon.
This geometric shape is used whenever an object with horizontal holes is printed. This avoids overhangs greater than 45° at the top of the hole, which are not (or at least not easily and clean) printable on FDM printers without support material.
Some people use teardrops only for larger holes (>4 or 5 mm diameter), since the overhangs are not such a big problem on smaller holes. While this is generally true, I tend to use teardrops even for smaller holes (3mm or even 1mm), since it turns out, that even these tiny holes look cleaner when printed in teardrop shape.
It always was kind of tricky to design objects containing teardrop shapes in classic CAD apps, since the teardrop shape isn’t a standard primitive in those applications (at least not in those I used).
This luckily changed with the release of OpenSCAD and it’s ability to use user written libraries.
At the latest with the release of Randy Young’s great Libs.scad library, using teardrops instead of cylinders for punching holes into objects is easy as pie.

Here’s the code of teardrop module from the Libs.scad library. I changed the Libs.scad code on my computer to use the polygon code instead of whosawwhatsis’ projection code, since the projection code takes forever to render in CGAL mode.

module teardrop(radius=5, length=10, angle=90) {
	$fn=resolution(radius);

	rotate([0, angle, 0]) union() {
		linear_extrude(height = length, center = true, convexity = radius, twist = 0)
			circle(r = radius, center = true);
		linear_extrude(height = length, center = true, convexity = radius, twist = 0)
			polygon(points = [
				[radius * -cos(-45), radius * sin(-45)],
				[radius * -cos(-45), radius * -sin(-45)],
				[(sin(-135) + cos(-135)) * radius, 0]],
				paths = [[0, 1, 2]]);
	}
// This code take forever to render:
// teardrop module by whosawhatsis <www.thingiverse.com/thing:3457>
// Creative Commons LGPL, 2010.  I added default values and resolution code
/*	rotate([0, angle, 0]) union() {
		linear_extrude(height = length, center = true, convexity = radius, twist = 0)
			circle(r = radius, center = true);
		linear_extrude(height = length, center = true, convexity = radius, twist = 0)
			projection(cut = false) rotate([0, -angle, 0])
			translate([0, 0, radius * sin(45) * 1.5])
			cylinder(h = radius * sin(45), r1 = radius * sin(45), r2 = 0,
					center = true);
	}*/
}

The problem with teardrop holes is, that they need considerably more space. This can be a real problem, when the main object is limited in size for one reason or another.

For example, this is a ball bearing retainer:

 

When simply using teardrops instead of cylinders for the holes, the result would be this:

As you can see, the larger footprint of the teardrop shape becomes a real problem with the larger holes in front and back of the retainer. In this case, the structural stability might still be good enough, since the smaller center bore  is still closed at the top. But often teardrop holes just aren’t an option unless you significantly re-design the main object (and usually make it larger).

Well, it turns out there is another option after all:

Introducing the Flat Teardrop

The solution is simple. Although overhangs > 45° are a problem in 3D printing, reasonably short bridges aren’t!

So why not just cut off the dead space in the tip of a teardrop?

 

 

 

I wrote a new module in OpenSCAD, called flatteardrop. This module is derived from the original teardrop module in Libs.scad:

module flatteardrop(radius=5, length=10, angle=90, luck=0) {
	$fn=resolution(radius);

	sx1 = radius * sin(-45);
	sx2 = radius * -sin(-45);
	sy = radius * -cos(-45);
	ex = 0;
	ey = (sin(-135) + cos(-135)) * radius;

	dx= ex-sx1;
	dy = ey-sy;

	eys = -radius-luck;
	dys = eys-sy;
	ex1 = sy+dys*dx/dy;
	ex2 = -ex1;

	rotate([0, angle, 0]) union() {
		linear_extrude(height = length, center = true, convexity = radius, twist = 0)
			circle(r = radius, center = true);
		linear_extrude(height = length, center = true, convexity = radius, twist = 0)
			polygon(points = [
				[sy, sx1],
				[sy, sx2],
				[eys, ex2],
				[eys, ex1]],
				paths = [[0, 1, 2, 3]]);
	}
}

Since the top is cut at radius height of the theoretical cylinder inside the teardrop, it might be a problem when the bridged part at top of the flat teardrop sags a bit during printing. This might happen when the bridge gets longer, i.e. on larger teardrops.

As a countermeasure it’s possible to add a little bit height to the cut “for luck”. To do so, set the value of the luck parameter to the additional height. However, the default value of this parameter is 0 and simply can be omitted in most cases.

The module makes use of the resolution function of the Libs.scad library. If you add the flatteardrop module to this library (as I did on my computer), it just works. If you plan to use the flatteardrop module separately, you might want to comment out the line

$fn=resolution(radius);

or set $fn to a fixed value (e.g. 36).

High resolution whistling

I absolutely love Junior Veloso’s high resolution print of my Whistle design:

His homemade resin-based 3D printer seems to work really, really well.

According to his blog, he plans to somehow publish documentation and maybe even kits with the required parts for his 3D printer design.

I can’t wait to get my hands on one of these printers :)