I’m in the process of building some aerodynamic bits and pieces for the DF to be used by Peter Borenstadt at the Battle Mountain event coming up in September. I’ve made him a more aerodynamic hood and now I’m working on some wheel fairings to cover the exposed tires both front and rear. The front wheel fairings will be attached to the bottom of stock DF pants. The rear wheel fairing will attach to the underside of the DF. I decided to start with the rear wheel fairing.

This fairing needed to fit the contours of the underside of the DF. Rather than building the prototype of the fairing directly on the DF, I made a mold of the rear underside of the DF and made a copy from that mold to work on.

So the idea was to use the copy as the base for the plug. I would then form the fairing shape on the copy which would complete the plug. I would take a mold of the plug and I’d be ready to produce the actual part.

I designed the basic shape in Fusion 360. I translated that design to patterns to cut from a pink foam sheet using the software Slicer for Fusion 360. I then built a full scale version of that design from the foam cutouts, epoxy resin, body filler and a lot of sand paper. Next I fused the shape on to the plug base and added fillets where the vertical faces met the horizontal faces. I then made a mold of the completed plug which is the orange piece shown below.

Here as some photos of the resulting wheel fairing. The part was made with 2 layers of carbon fiber twill using the vacuum bagging technique. The final trimmed part ended up weighing 112 g.