In Which I Designed a Part for My Truck, and Got It Built From Scratch

Recently I converted my old Ford pickup to diesel, and I needed to make a bracket to hold a throttle position sensor, which helps to control the new transmission. Often I wing this sort of thing, working from notebook drawings or cardboard models. But this time I decided to use 3-D CAD modeling, CNC manufacturing and 3-D printing to design and fabricate the part to the exact specifications I wanted.

Printed Bracket: Step 1

STEP 1: DESIGN

Using Alibre Design Expert 3-D CAD software, I created an assembly, which lets you model previously designed parts as they will eventually fit together. In the assembly, I placed my throttle position sensor (TPS) over the fuel-injection pump to derive all the dimensions of my bracket from those two parts. I then modeled the bracket that will attach the TPS to the pump.

Printed Bracket: Step 2

STEP 2: FABRICATION

I first 3-D-printed an inexpensive prototype to verify that my design would work. Then I looked to machine it. Parts better suited to conventional machining require a multi-axis CNC machine. For anything made from flat parts, a laser cutter is the best tool. Because my bracket would be made of sheet metal, I took the CAD model to a local shop that has a punch press, another type of CNC machine.

And, of course, video of the construction:

FABRICATION SHOPS AROUND THE WEB

eMachineShop: For laser cutting, injection molding, and a variety of other machining processes.
Ponoko: For laser cutting of plastics, cardboard, wood and other materials.
Shapeways: For 3-D printing.