FCS sizing

i shaped a big guy tri fin. i am stuck on what type of FCS fins to use. not sure on a certain size. the board is rather thick,prob. about 2.75. also…when measuring for you fin placement…i understand that you mark off the rail for the trailing edge, but how far apart should the leading edge be marked? 3.5" from the trailing??

4" up is ok…AM’s or R’s are for big guy shapes or G6’s

is it better to know what fins you will be using before you make the fin marks on the blank? say a fin has a 4 1/4" base…should i mark the trailing edge then make the leading edge mark 4 1/4" away? or is there a standard # used which will work for all fin sizes?

Check out the photo resources under tools. There is a jig in there, #515, similar to what I use. FD

4 1/2" is the dimension which works with the stock fin install jigs from FCS and Fin Solutions.