Popular Science's Vin Marshall shows off new video: Bracketology
Featured in the January 2012 Issue of Popular Science Magazine
Recently Vin Marshall from PopSci.com converted his old Ford pickup to diesel, and he needed to make a bracket to hold a throttle position sensor in place, which helps to control the new transmission.
Vin would normally just draw this sort of thing on a napkin and work from that drawing or make real cardboard models. But this time he decided to use Alibre Design 3-D CAD software that he picked up during the filming of his new TV show NatGeo’s “How Hard Can It Be”. For this project he used the Professional edition of Alibre to help design it, then he printed the bracket on a 3D Systems printer and finally he fabricated the part on a CNC machine.
Giving the Design some Gas!
Vin modeled the existing parts of the engine that need to be held together by the bracket. In Alibre Design it is very easy to pick up dimensions from the parts you have already modeled. He then sketched the outline of his bracket, dimensioned the size of the holes for the connecting bolts. Then he converted the sketch into a sheet metal part with a flange for added stability. From here in the program you can take the part, place it back into the assembly to see spacing and alignment, so you can see for yourself that it going to fit perfectly, before you ever make it.
3D Printing the Bracket
The next step Vin took was to jump out of Alibre Design and Jump into Bits From Bytes AXON Software. This software allows you to print real 3D models of your design with extruded plastic. Once you import your model you want to position your part on the simulation BED and rotate the model to the direction you want it to prnt. Once you have that file complete you generate the G-CODE and begin the process of 3D printing your prototype.
The 3D Systems BfB 3000 printer is used here; PLA Plastic is being fed UP through the motor heads, heated to about 195 degrees and then the design it is printed out on and X, Y and Z coordinate system. This whole process took about 3 and one half hours, the video of the build is condensed down below.
Make it out of Metal
Finally Vin, install the prototype on his Ford and tested the unit for fit and postion, it worked so well he used the part on the truck for 3 weeks while the machine shop fabricated the real part out of aluminum. Vin did this with Sheet Metal and a CNC Machine and affixed the new bracket to the motor and connected the Throttle Position Sensor.