Monday, January 22, 2018

Wind deflector part 2

After creating the template (see last post), I applied masking tape to the polycarbonate where it would be cut. Then I marked the shape of the template on to the masking tape, including the eye bolt hole centres. A soft cloth was put on the bench to avoid any scratches when cutting. The deflector was cut to the shape of the template using an electric jig saw (use the correct blade and a very slow speed to avoid melting the material - I used speed 2 out of 5). The part cut from the bottom was supported by tape to avoid it snapping when the cut was near to the end.

Polycarbonate cut to shape
Next the four holes for the seat belt anchorages (eye bolts) were drilled. A 4mm hole was drilled first as a pilot hole with a sharp HSS bit. After checking that the pilot holes were in the right place, these were then drilled to size, using a 22mm hole saw.

The edges of the polycarbonate were shaped with a file. Then they were finished off with P80, P400 and P1000 wet n dry paper. Finally the edges were buffed with a foam pad and G10 polishing compound, using the polishing machine. The edges now look like glass.
The fixings, but note that the screws used were 30 mm long
Next the deflector was temporarily fitted on to the roll hoops using just the seat belt eye bolts. The six fixing holes (to locate the P-clips) were marked on to masking tape.

A soft cloth was placed on the bench again to protect the polycarbonate and then the holes were drilled out gradually to 6 mm. It is advisable to drill in to a block of wood to stop the polycarbonate cracking. The deflector was then temporally attached to the roll hoops again, with the P-clips and using M6 x 30 mm button head screws with nylon nuts to make sure they were in the correct position.

Once I was happy with the fit and finish, I removed the protective film from either side of the polycarbonate. Then I wiped the dust from the polycarbonate with a soft cloth.

The deflector was then fixed in its final place. The metal washers go under each screw head and against the outside of the P-clip, with nyloc nuts to stop the deflector working lose (make sure that the plastic washers are against the polycarbonate to reduce the likelihood of cracking). Finally the eye bolts were refitted, along with the seat belts.
Finished wind deflector in place
Does it work? Well it doesn't stand out or detract from the Cobra's lines. It does cut down on the wind behind you head significantly, but it does not totally eliminate it. To do that a hood, a hardtop or a tin top would really solve the problem.

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