Step 1: Acquire Materials
1. 1" thick aluminum plate that is roughly 100mm square
2. 1/4" End Mill that is longer than 1"
3. 1/4" Drill Bit
4. CAD/CAM software
5. CNC Machine
6. (4) 6mm x 50mm bolts
7. (3) 6mm x 40mm bolts
8. (3) 1/4" ID x 1" long steel spacer
9. (2) New Throttle body gaskets for your intake (about 2$ a piece)
The total cost from the hardware store was less than 8$.
Step 2: Make the Model
Step 3: Make the Tool Paths
For this cut, I used the following speeds:
Feed Rate - 15 in/min
Spindle - 2400rpm
The endmill is 1/4" diameter and has 4 flutes. Normally, you shouldn't used 4 flutes for aluminum, but it works.
When using the CAM (computer aided machining) software you
1. Import or Create the model
2. Create the blank
3. Create the tool
4. Create the tool path and select the proper faces
** I usually choose to not use a specific corner for machining, that way I don't have to use the edge-finder.
** Adding tabs to your part will keep large cut out pieces from flying around and/or breaking the tool
After it is finished machining, use a dremel and cut the tabs off. Smooth them down and the inside will be finished.
Then use a band saw to cut out the outside dimensions. With a rough blade, this should take about a minute--pretty simple. The outside dimensions are not at all important, just as long as you don't creep into the drill holes or the center.
Step 4: Install the Part
You'll need some longer screws, and an additional gasket (available at auto parts store).
Using your hand tools, unbolt the current throttle body, add the spacer, and bolt everything back together.