Thanks, gdaddy!
I’m actually leaving the install to a professional. I bought the board and negotiated a price including the modifications. They told me that I cannot buy FCS2 inserts and equipment unless I am a ‘licensed installer’ or something like it. I hope the guy knows what he is doing, but chances are he does. If the fins rip out, that’ll be a lesson learned for next time.
I decided to start with the FCS II Performer PC Carbon Quad Set (large) plus the FCS II Performer Centre (large). That way, I will not need to use a key to switch fins. http://www.surffcs.com.au/…/fcs-ii-performer-centre…
The centre fin box at 10’’ is just long enough to allow the snap-in FCS2 Performer fin to sit where the original thruster centre fin used to be, and the front of the box is far enough forward to place a Gullwing Fin in the recommended position 18.5cm from the tail. I hope the tail is thick enough to fully accept the box without sanding any off it. I usually use one of Roy Stewarts polycarbonate Gullwing Fins, with or without the BLEF bumps. But for this board, I might go back to using the snap-in Gullwing fin that came with one of my Zots. I want to change fins while in the surf, and also have another Franken-McCoy in the family. With a bit of collaboration from other McCoy afficionados a complete change of fin setup in the surf will be possible.
I have not been able to find clear instructions for quad fin placement, except the McKee tables. The attached photo shows where I think McKee would have placed the fins, compared to my placement. The other difference to the McKee recommendations is that the distance to the stringer at the nose of the board is a bit larger. That is dictated by the already installed front fins, and my conviction that all 4 fins should point to a common conversion point.
Here are some measurements for those who might want to modify a Nugget to Quad themselves. The McKee recommendations are in brackets behind:
XF Nugget 6’6’':
Tail width at 12’‘: 43.6cm 17 + 3/16’’
Front fins distance from tail: 29.2cm 11+1/2’’ ( 28.7cm McKee )
Front fin distance from rail: Measured perpendicular to stringer (not shortest distance): 3cm
Front fin cant: 5deg
Front fins distance from stringer and from each other: rear of fin 18.5cm; front of fin 18cm from stringer;
Rear centre fin distance from tail: 8.6cm (8.8cm McKee)
Final rear quad placement values chosen by me:
16.6cm from tail (13.3cm McKee) ; using 3degree cant boxes.
12.0cm from stringer. (10.4cm McKee)
Rear fin projection line 5.2cm from stringer at nose ( McKee: 2.86cm)
Front fin line 8cm from stringer at nose (McKee: 6.985cm); this was of course already built into the board by the placement of the front FCS2 plugs.