CS 285: SOLID MODELING, Spring 2002

Assignment #5

Prepare your Design for Layered Manufacturing

Scale your Bell design, so that it fits inside a 2-inch cube. At this scale, its wall thicknesses should be at least 1.5mm (60 mils). Enhance and refine your bell design so that it becomes a usable bell shape -- with either a handle or a way to hang it.

After you have prepared a clean and consistent representation of your design, choose the "implementation/refinement parameters" in your SLIDE program, so that the B-rep of your object has between 5000 and 20,000 triangles. Save this object as a .STL file.

The next step is to check that this design is indeed ready for fabrication on a layered Solid Free-form Fabrication (SFF) machine. We will aim our current designs at a Fused-Deposition Modeling (FDM) machine. The machine from Stratasys comes with its own preprocessing software: QuickSlice.

QuickSlice now has been installed on the machines in 349 Soda. You find the application as "quickslice" on the desktop. Unfortunately, it does not know what machine we have in Etcheverry, so you will have to tell it, that we have a FDM 1650, and that we want 0.01inch slices, and run with a TP12 nozzles, dispensing ABS P400 Material and ABS P400 Release.

Examine your shapes generated in SLIDE with the QuickSlice program. A more detailed enumeration of the steps that you should go through in QuickSlice can be found in "Running your Design through QuickSlice".
Basically, you will:

orient and scale your design for a not-too-lengthy build time.
capture a representative shaded view of your object, and save it as a jpg or gif file.
cut the shape into the individual layers from which the object will be composed,
inspecting these layers to make sure that the machine understands what you had in mind,
create the supports necessary beneath extreme overhangs that slope out by more than 45 degrees,
form a "base" on which the part will be constructed.
generate the actual paths ("roads") along which the plastic filament will be deposited,

Check that the walls are thick enough to accommodate the outline roads as well as some amount of internal zig-zag-fill roads to give the walls sufficient physical strength.

Finally you should ask for an estimation of the build time, and make sure that it is reasonable to build that part. (Assume you would have to pay 5$-10$ per hour.)

If all seems OK, save that process plan as a g-zipped .STL-file, and put it into a "public" directory that you create as follows:

Creating your "public" directory

Due Date: Tuesday, 2/19/2002, 5pm

E-mail me the shaded jpg/gif-image of your part,
and a couple of paragraphs describing your approach to make a (mostly) clean B-rep,
and the tricks you used to work around any QuickSlice problems encountered.

Place the .STL file into your "public" directory (from where we will grab it with the FDM machine).

Sample Solution

As an inspiration, here is Jane Yen's solution of a similar assignment in Spring 2000.

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