3d printed quite cap?

The radius for the cap is 21.75mm, and i made it 15mm tall to void the generator tube while as tall as possible. There is a M4 screw go through the middle of the cap to connect with the stove. Wall thickness:1mm
all the holes are 0.7mm and there are 225 of them.
A rendering picture from shapeways:

It would cost around $32 to printed from shapeways with stainless steel.
But before that I will use a makerbot to print a plastic sample.

Liang, for any of us who are not familiar with contract design and 3D printing of prototypes, could you explain a little more about the process? Did Shapeways render that image of your "quiet cap" for you, or did you render it yourself with Sketchup or Blender or some other software? Am I correct in understanding that the total cost for all necessary services from Shapeways including printing of the final stainless steel part is less than $40?

You are very resourceful, and I appreciate your description of your project. It looks like this part will do what it is designed to do, and the methods you are using are clever. I think there are probably others like myself who would love to know more about the process.

Hey Colin

Software wise:
openscad is usually the first tool i use for this type of job.
it provides a list of shapes (cube,cylinder,etc) a list of transitions(scale, rotate, translate) and a list of operators(union, difference).
it enables you to create a simple model with basic shapes.
Also by importing .dxf and .stl file you are able to have complex shapes from outside source.
For example here i made the cap myself, and added a gear from gear.stl on top of the cap.

Blender is also a really good tool, but I only use it for coloring models.
inkscape+"path to openscad" enables you to convert 2d pictures to 3d models for openscad.

3d printers:
most of 3d printers under $1000 prints abs plastic or some other kind of plastic.
the accuracy is bad too.
Below is a 3d key cap i printed from a Makerbot.

Fancy printers can print resin and even metal. but that comes with a very high price tag.
Luckily there are online printing service available.
I got the same key cap printed from shapeways for around $23

shapeways allows you to upload .stl .dxf and some other format of 3d model files, makes quotations based on volume. And yes around $34 for the quite cap since it's around 3.4cm^3.

What I usually do is design a model, try it on cheap 3d printers which i have access to locally. If everything looks good send it to shapeways for high accuracy printing.

No reason it wouldn't work. Used to be able to get these in super-limited quantities since they were hand-made but they were really really expensive.

Might need a few tries to get it "just right" but I'm interested in hearing how it works for you.

That is a cool looking project, thanks for posting! Looking forward to seeing how it turns out.

Some other good resources for 3d diyers:

Makexyz.com – cheaper and more local than shapeways (but more limited selection of materials)

123d design: fairly intuitive and powerful free cad program for 3d objects.

This is a prototype printed by ultimaker with pla plastic and 0.2 level thickness.
It is used to test the fit and functions.
Good news it fits perfectly. Bad news the lower level vent holes might be to low.
And also vent holes might be too small.
And it's too tall to reuse the same screw for the origin one(not a big deal).